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Welcome to a special Sky at Night. | 0:00:13 | 0:00:16 | |
This marks our 60th anniversary. | 0:00:16 | 0:00:19 | |
The first episode of Sky at Night was broadcast live | 0:00:19 | 0:00:21 | |
on the 24th of April, 1957. | 0:00:21 | 0:00:24 | |
And we've come a long way since then. | 0:00:24 | 0:00:26 | |
The programme started before the dawn of the space age, | 0:00:26 | 0:00:29 | |
when the idea of sending probes to distant planets | 0:00:29 | 0:00:32 | |
was nothing more than a dream. | 0:00:32 | 0:00:34 | |
In fact, we knew so little that the idea of advanced life on Mars | 0:00:34 | 0:00:38 | |
seemed a distinct possibility. | 0:00:38 | 0:00:40 | |
So we've come here to the Royal Observatory, Greenwich, | 0:00:40 | 0:00:43 | |
home of British astronomy, | 0:00:43 | 0:00:45 | |
to look back and see how our understanding of the universe | 0:00:45 | 0:00:48 | |
has changed over the past six decades. | 0:00:48 | 0:00:50 | |
Welcome to The Sky at Night. | 0:00:50 | 0:00:52 | |
The 60th is a diamond anniversary. | 0:01:30 | 0:01:33 | |
And the Department of Earth Sciences at UCL have been kind enough | 0:01:34 | 0:01:37 | |
to lend us this. | 0:01:37 | 0:01:39 | |
It's called carbonado, and it's a black diamond. | 0:01:39 | 0:01:42 | |
Now if you have a closer look | 0:01:42 | 0:01:43 | |
it might seem a little disappointing | 0:01:43 | 0:01:45 | |
because it's not bright and shiny, like your everyday diamond, | 0:01:45 | 0:01:47 | |
but it has a much more interesting story. | 0:01:47 | 0:01:50 | |
One that is very relevant to today's programme. | 0:01:50 | 0:01:52 | |
More about that diamond later, | 0:01:54 | 0:01:55 | |
but first, back to the progress we've made in the last 60 years. | 0:01:55 | 0:01:59 | |
We'll be taking a range of subjects | 0:01:59 | 0:02:01 | |
and with the help of The Sky at Night archive, | 0:02:01 | 0:02:03 | |
finding out what we've learned during the time we've been on air. | 0:02:03 | 0:02:06 | |
We'll be going back to 1957, | 0:02:08 | 0:02:11 | |
to see how we observed the night sky back then. | 0:02:11 | 0:02:14 | |
Dallas Campbell will be retracing on a bicycle the journeys that have | 0:02:16 | 0:02:20 | |
taken us from the surface of the Earth to the furthest reaches | 0:02:20 | 0:02:23 | |
of the solar system. | 0:02:23 | 0:02:25 | |
And Jim Al-Khalili will be showing us how in just 60 years | 0:02:28 | 0:02:32 | |
we've created an entirely new history of the universe. | 0:02:32 | 0:02:35 | |
Using maths and physics, | 0:02:36 | 0:02:38 | |
we can really understand how the universe was made, | 0:02:38 | 0:02:42 | |
where it came from, how it works, and how it might possibly end. | 0:02:42 | 0:02:46 | |
But to start we have to go back to the beginning, to 1957. | 0:02:49 | 0:02:53 | |
April 1957 was a very different world. | 0:02:57 | 0:03:01 | |
Our culinary tastes were apparently so unsophisticated | 0:03:02 | 0:03:06 | |
that Panorama could broadcast an April Fool's report | 0:03:06 | 0:03:08 | |
into the spaghetti harvest in Switzerland. | 0:03:08 | 0:03:12 | |
Harold Macmillan had just become Prime Minister. | 0:03:12 | 0:03:14 | |
And a new series, with a new presenter - Patrick Moore - began. | 0:03:16 | 0:03:21 | |
Good evening. Tonight, I want to show you a rather unusual film. | 0:03:24 | 0:03:28 | |
'But at that time our ideas about the solar system | 0:03:29 | 0:03:32 | |
'were very different from what they are today.' | 0:03:32 | 0:03:35 | |
The first programme was about the comet Arend-Roland, | 0:03:35 | 0:03:38 | |
but we don't have a copy. | 0:03:38 | 0:03:39 | |
It was broadcast live and never recorded, | 0:03:39 | 0:03:42 | |
but I do have this book, which Patrick wrote about Mars in 1956. | 0:03:42 | 0:03:47 | |
And after dismissing the idea of Earth-like animal life, | 0:03:47 | 0:03:51 | |
he goes on to say this. | 0:03:51 | 0:03:52 | |
"When we turn to plant life the situation is brighter, | 0:03:52 | 0:03:56 | |
"and as we have seen it is almost certain | 0:03:56 | 0:03:59 | |
"that extensive vegetation does exist on Mars." | 0:03:59 | 0:04:02 | |
It seems ridiculous today, | 0:04:02 | 0:04:04 | |
but 60 years ago it was a widely held belief | 0:04:04 | 0:04:07 | |
that there were plants on the surface of the red planet. | 0:04:07 | 0:04:10 | |
And, really, there's no better example | 0:04:10 | 0:04:13 | |
of how fast our ideas have changed than Mars. | 0:04:13 | 0:04:16 | |
To guide us through 60 years of astonishing discoveries | 0:04:18 | 0:04:21 | |
about the Red Planet, Maggie has been talking to Monica Grady. | 0:04:21 | 0:04:25 | |
Monica, it seems amazing to me | 0:04:26 | 0:04:28 | |
that just 60 years ago people thought that Mars | 0:04:28 | 0:04:31 | |
was covered in vegetation. Why was that? | 0:04:31 | 0:04:33 | |
Well, it's because of pictures like this. | 0:04:33 | 0:04:35 | |
This was taken in about 1956 | 0:04:35 | 0:04:38 | |
from one of the Earth's biggest telescopes, | 0:04:38 | 0:04:40 | |
and you can see this big, dark shadow here | 0:04:40 | 0:04:43 | |
right across the front of the planet, | 0:04:43 | 0:04:46 | |
and this is interpreted as being a sort of rainforest. | 0:04:46 | 0:04:51 | |
And at the time, this was the best that the telescope could do. | 0:04:51 | 0:04:54 | |
Yeah, it's pretty fuzzy, you can't see much here at all. | 0:04:54 | 0:04:57 | |
No, you can't. | 0:04:57 | 0:04:58 | |
The problem with looking from Earth | 0:04:58 | 0:05:00 | |
is that you're looking through the Earth's atmosphere, | 0:05:00 | 0:05:02 | |
which immediately starts blurring things, | 0:05:02 | 0:05:04 | |
so what you need to do is get above the Earth's atmosphere. | 0:05:04 | 0:05:07 | |
In 1964, Nasa launched the probe Mariner 4. | 0:05:12 | 0:05:15 | |
Eight months later it flew within 10,000km of Mars, | 0:05:17 | 0:05:21 | |
and pixel by pixel returned 22 images of the planet's surface. | 0:05:21 | 0:05:26 | |
It seems like a long way to go for 20 photographs. | 0:05:26 | 0:05:29 | |
Well, I mean these pictures from Mariner 4 | 0:05:29 | 0:05:32 | |
completely changed part of our ideas of Mars. | 0:05:32 | 0:05:37 | |
What do they show us? | 0:05:37 | 0:05:38 | |
Well, for a start you've got this hazy bit here and this is... | 0:05:38 | 0:05:41 | |
Hey, Mars has got an atmosphere, | 0:05:41 | 0:05:43 | |
so that's something that we didn't know, | 0:05:43 | 0:05:45 | |
and you can see more structure here. | 0:05:45 | 0:05:47 | |
You can see that there are these sort of circular patches. | 0:05:47 | 0:05:51 | |
Now, at the time they were called craters, | 0:05:51 | 0:05:54 | |
but there are two sorts of craters. | 0:05:54 | 0:05:56 | |
There's the crater at the top of a volcano | 0:05:56 | 0:05:58 | |
and there's the crater made by impact from an asteroid, | 0:05:58 | 0:06:01 | |
and there's lots of discussion as to what sort of craters they were. | 0:06:01 | 0:06:05 | |
For those who long to find life on Mars, | 0:06:05 | 0:06:08 | |
the Mariner 4 pictures were a disappointment, | 0:06:08 | 0:06:11 | |
but they weren't definitive. | 0:06:11 | 0:06:13 | |
So just four years later Nasa tried again. | 0:06:13 | 0:06:16 | |
Good evening. We've just had some amazing photographs sent back by the | 0:06:16 | 0:06:19 | |
American probe to Mars, Mariner 6. | 0:06:19 | 0:06:22 | |
As Mariner 6 approached in 1969, | 0:06:24 | 0:06:26 | |
there was much excitement that Mars would finally give up its secrets. | 0:06:26 | 0:06:31 | |
Mariner 6 came down over this direction, | 0:06:32 | 0:06:35 | |
over these so-called deserts. | 0:06:35 | 0:06:37 | |
The question is of course, are these dark areas due to organic matter, | 0:06:37 | 0:06:40 | |
vegetation, if you like, or are they not? | 0:06:40 | 0:06:43 | |
But when the pictures came back, | 0:06:43 | 0:06:44 | |
they revealed a dry and barren surface. | 0:06:44 | 0:06:48 | |
Now, what about this all important question of life on Mars? | 0:06:48 | 0:06:51 | |
Primitive life, there may be, I don't even think so. | 0:06:51 | 0:06:53 | |
Intelligent life? Certainly not. | 0:06:53 | 0:06:55 | |
So, in other words, you rather think that Mars is a dead planet? | 0:06:55 | 0:06:57 | |
Absolutely, dead as a dodo. | 0:06:57 | 0:06:59 | |
Once it was realised there was no complex life on Mars, | 0:06:59 | 0:07:02 | |
attention turned to the planet's past. | 0:07:02 | 0:07:05 | |
And here, the story became much more interesting. | 0:07:05 | 0:07:08 | |
So, this is from one of the Viking orbiters, | 0:07:09 | 0:07:12 | |
and it's not a single picture. | 0:07:12 | 0:07:13 | |
It's lots and lots of pictures. | 0:07:13 | 0:07:15 | |
It's a mosaic that has been put together. | 0:07:15 | 0:07:16 | |
-But it's glorious. -It's absolutely fantastic. | 0:07:16 | 0:07:19 | |
Just looking at these pictures | 0:07:19 | 0:07:21 | |
started to really capture how close Mars was to Earth | 0:07:21 | 0:07:25 | |
in many of its features. | 0:07:25 | 0:07:26 | |
It's got these volcanoes, which are like the volcanoes on Hawaii. | 0:07:26 | 0:07:29 | |
It's got this rift valley, which is like East Africa, | 0:07:29 | 0:07:32 | |
and, of course, it's got its icecaps. | 0:07:32 | 0:07:34 | |
But you've also got the features that on Earth we would interpret | 0:07:34 | 0:07:38 | |
as being from rivers, | 0:07:38 | 0:07:39 | |
so you've got something that looks as if | 0:07:39 | 0:07:42 | |
it's going out into a huge delta. | 0:07:42 | 0:07:43 | |
You've got other channels, meandering channels, | 0:07:43 | 0:07:46 | |
and these were formed by flowing water. | 0:07:46 | 0:07:49 | |
They were formed by rivers. | 0:07:49 | 0:07:50 | |
So, with the orbiter, we suddenly get evidence | 0:07:50 | 0:07:53 | |
-for past liquid water on Mars? -You do. | 0:07:53 | 0:07:54 | |
So, you get a picture of a planet | 0:07:54 | 0:07:58 | |
which has had all the ingredients, | 0:07:58 | 0:08:01 | |
all the things that would allow life to get going. | 0:08:01 | 0:08:05 | |
So the idea is that, yes, Mars could have harboured life, | 0:08:05 | 0:08:09 | |
it might still harbour life, | 0:08:09 | 0:08:11 | |
but if it is, it's not big life. | 0:08:11 | 0:08:13 | |
We're looking at small life. | 0:08:13 | 0:08:15 | |
So, if we are still looking for life, how do we find out the detail? | 0:08:15 | 0:08:17 | |
Well, what you have to do is, you have to get down there, | 0:08:17 | 0:08:21 | |
so you have to actually land. | 0:08:21 | 0:08:24 | |
That takes us to these pictures? | 0:08:24 | 0:08:26 | |
This brings us right up to date | 0:08:26 | 0:08:28 | |
with the most recent spacecraft to land on Mars, | 0:08:28 | 0:08:31 | |
which is Curiosity, | 0:08:31 | 0:08:33 | |
which landed a few years ago and has been trundling across the surface | 0:08:33 | 0:08:37 | |
near Mount Sharp in the Gale Crater. | 0:08:37 | 0:08:39 | |
It has been taking the most amazing pictures. | 0:08:39 | 0:08:42 | |
These are so brilliant. I feel as if I could step inside. | 0:08:42 | 0:08:45 | |
We've come a long way in 60 years. | 0:08:45 | 0:08:47 | |
We started off with that fuzzy image 60 years ago. We're now on this, | 0:08:47 | 0:08:50 | |
where you can actually see the details of single pebbles. | 0:08:50 | 0:08:53 | |
What are we looking for here? | 0:08:53 | 0:08:54 | |
Well, we're still looking for life on the planet. | 0:08:54 | 0:08:56 | |
We still haven't found it. | 0:08:56 | 0:08:57 | |
So far, a lot of the missions have been following the water. | 0:08:57 | 0:09:00 | |
Now what we haven't done yet is dug below the surface. | 0:09:00 | 0:09:04 | |
Below the surface, | 0:09:04 | 0:09:06 | |
there's a chance that you might find something still living. | 0:09:06 | 0:09:11 | |
Very difficult to get into those places. | 0:09:11 | 0:09:15 | |
We need to get more intelligent rovers and eventually, | 0:09:15 | 0:09:19 | |
we need to get the most intelligent rover of all, | 0:09:19 | 0:09:23 | |
and that's a person. | 0:09:23 | 0:09:24 | |
Can it be me? | 0:09:24 | 0:09:26 | |
I just can't wait to see what the next 60 years bring. | 0:09:27 | 0:09:30 | |
-It's going to be brilliant. -Yes. Thank you so much for coming in. | 0:09:30 | 0:09:32 | |
My pleasure. Thanks a lot. | 0:09:32 | 0:09:33 | |
Hello, this is Buzz Aldrin, Apollo 11 astronaut, | 0:09:38 | 0:09:43 | |
first landing on the moon, now working on humans to Mars. | 0:09:43 | 0:09:48 | |
I do remember Patrick Moore with great respect, great reverence. | 0:09:48 | 0:09:54 | |
I want to wish The Sky at Night happy birthday, | 0:09:54 | 0:09:58 | |
60 years of all of that wonderful education | 0:09:58 | 0:10:03 | |
as to what is going on up there at night. Thanks so much. | 0:10:03 | 0:10:08 | |
It's been a joy having you with us. | 0:10:08 | 0:10:11 | |
The Sky at Night isn't the only astronomical institution | 0:10:14 | 0:10:17 | |
celebrating its 60th birthday this year. | 0:10:17 | 0:10:20 | |
This is the Lovell Telescope, at Jodrell Bank, in Cheshire. | 0:10:20 | 0:10:24 | |
It was first switched on in August 1957. | 0:10:25 | 0:10:28 | |
It's still one of the most sensitive radio telescopes in the world. | 0:10:30 | 0:10:34 | |
Over the years, we've filmed here on many occasions. | 0:10:34 | 0:10:37 | |
To mark our shared anniversary, we asked Tim O'Brien, | 0:10:41 | 0:10:44 | |
one of the astronomers at Jodrell Bank, | 0:10:44 | 0:10:46 | |
to reveal some of its secrets, | 0:10:46 | 0:10:49 | |
and to celebrate its most important contributions to astronomy. | 0:10:49 | 0:10:53 | |
This is the incredible 76-metre wide 3,200 tonne Lovell Telescope, | 0:10:55 | 0:11:02 | |
the brainchild of Bernard Lovell, | 0:11:02 | 0:11:04 | |
an astronomer who had an ambitious vision. | 0:11:04 | 0:11:07 | |
Back in the 1950s, | 0:11:09 | 0:11:11 | |
Lovell was a pioneer in the relatively untested science | 0:11:11 | 0:11:15 | |
of radio astronomy. | 0:11:15 | 0:11:17 | |
They used huge dishes as aerials, | 0:11:17 | 0:11:20 | |
gathering not light but radio waves from space | 0:11:20 | 0:11:23 | |
in the hope that this would reveal new information about the universe. | 0:11:23 | 0:11:28 | |
His revolutionary proposal was to build this telescope, | 0:11:29 | 0:11:33 | |
ten times larger than any that had gone before. | 0:11:33 | 0:11:38 | |
But in those early days, | 0:11:38 | 0:11:39 | |
few believed in radio astronomy as much as Lovell. | 0:11:39 | 0:11:42 | |
Even as construction began, | 0:11:44 | 0:11:46 | |
he knew he was taking a high-stakes gamble... | 0:11:46 | 0:11:48 | |
..as The Sky at Night discovered years later. | 0:11:49 | 0:11:53 | |
During the building of the telescope, | 0:11:53 | 0:11:55 | |
were there are any real crises, either with design or with cash? | 0:11:55 | 0:11:59 | |
Endless crises. | 0:11:59 | 0:12:00 | |
We started building the telescope in 1952, the foundations, | 0:12:00 | 0:12:04 | |
and very soon discovered that the cost, | 0:12:04 | 0:12:09 | |
whilst going to be far greater than the £30 million we got, | 0:12:09 | 0:12:12 | |
but I didn't tell anybody. | 0:12:12 | 0:12:14 | |
Then we had, I think, the most colossal stroke of luck, | 0:12:14 | 0:12:18 | |
that certainly I've ever had in my life. | 0:12:18 | 0:12:20 | |
The Russians launched the first of the Sputnik. | 0:12:22 | 0:12:25 | |
After a few days, we got a most magnificent radar echo | 0:12:25 | 0:12:29 | |
from the carrier rocket of the Sputnik. | 0:12:29 | 0:12:32 | |
I've still got it, showing it going over the Lake District. | 0:12:32 | 0:12:34 | |
200 miles above the Earth. | 0:12:36 | 0:12:37 | |
And it turned out, to my astonishment, | 0:12:37 | 0:12:42 | |
that this was the only instrument in the world | 0:12:42 | 0:12:44 | |
capable of detecting this rocket. | 0:12:44 | 0:12:46 | |
Suddenly, the telescope became world-famous | 0:12:46 | 0:12:50 | |
and the establishment finally realised its true value. | 0:12:50 | 0:12:53 | |
Now completely operational, | 0:12:55 | 0:12:57 | |
the telescope was pulled in two completely different | 0:12:57 | 0:13:00 | |
and often opposing directions - political and scientific. | 0:13:00 | 0:13:04 | |
The politicians wanted to use it to monitor our Cold War enemies, | 0:13:05 | 0:13:10 | |
tracking Russian missiles and space projects. | 0:13:10 | 0:13:13 | |
But away from the high-profile space tracking work, | 0:13:13 | 0:13:17 | |
the telescope was actually being used for real science, | 0:13:17 | 0:13:20 | |
and those early results were breathtaking. | 0:13:20 | 0:13:22 | |
This is a map of the whole of the sky, | 0:13:24 | 0:13:26 | |
but seen in radio waves rather than visible light. | 0:13:26 | 0:13:30 | |
It revealed that space was awash with radio. | 0:13:31 | 0:13:35 | |
It was a powerful scientific vindication of Lovell's vision. | 0:13:35 | 0:13:38 | |
And all the more amazing, | 0:13:39 | 0:13:41 | |
given that some key components of the telescope | 0:13:41 | 0:13:44 | |
were actually recycled. | 0:13:44 | 0:13:46 | |
We're here at the top of the towers, | 0:13:47 | 0:13:50 | |
right on the axis of the tipping of the ball, | 0:13:50 | 0:13:52 | |
and that tipping of the giant ball is done on these gear racks. | 0:13:52 | 0:13:56 | |
These are actually from the 15-inch guns of two World War I battleships. | 0:13:56 | 0:14:01 | |
Once all the engineering challenges had been overcome, | 0:14:03 | 0:14:06 | |
the new discoveries started to roll in. | 0:14:06 | 0:14:09 | |
When these first radio astronomers started to scan the skies, | 0:14:12 | 0:14:15 | |
they spotted intense points of radio light they called the radio stars. | 0:14:15 | 0:14:20 | |
We used the Lovell Telescope and other radio antennas | 0:14:20 | 0:14:23 | |
spread across the country to zoom in on these points of light. | 0:14:23 | 0:14:27 | |
We found they weren't stars at all, | 0:14:27 | 0:14:28 | |
they were actually distant galaxies | 0:14:28 | 0:14:30 | |
and they were powered by supermassive black holes. | 0:14:30 | 0:14:34 | |
These became known as Quasi Stellar Objects. | 0:14:34 | 0:14:38 | |
The Quasars. | 0:14:38 | 0:14:40 | |
Hardly noticeable to optical telescopes, | 0:14:40 | 0:14:42 | |
these objects completely changed the way we thought about the universe. | 0:14:42 | 0:14:47 | |
Turns out that this new radio sky | 0:14:48 | 0:14:51 | |
is not full of stars held by nuclear fusion, | 0:14:51 | 0:14:53 | |
like we see with our eyes, | 0:14:53 | 0:14:55 | |
it's actually full of supermassive black holes powered by gravity. | 0:14:55 | 0:14:59 | |
Gathering this kind of data from space is a huge technical challenge. | 0:14:59 | 0:15:04 | |
So the Lovell is constantly being updated and improved, | 0:15:04 | 0:15:08 | |
but that leaves it with its own share of quirky idiosyncrasies. | 0:15:08 | 0:15:12 | |
This is the control room. | 0:15:14 | 0:15:15 | |
At its heart is the control desk dating from 1957, | 0:15:15 | 0:15:19 | |
although it is now packed with new electronics. | 0:15:19 | 0:15:21 | |
Back in the day, the control system | 0:15:21 | 0:15:23 | |
was an ingenious electromechanical analogue computer. | 0:15:23 | 0:15:27 | |
There were ten boxes arrayed around the desk here, | 0:15:27 | 0:15:30 | |
packed with dials and whirring gears, | 0:15:30 | 0:15:32 | |
and they were used to drive the telescope | 0:15:32 | 0:15:35 | |
to exactly the position that the astronomers wanted. | 0:15:35 | 0:15:37 | |
Over its 60 years, the dish itself has undergone some major overhauls. | 0:15:41 | 0:15:46 | |
In the 1970s, a new surface was built, several metres above the old. | 0:15:47 | 0:15:53 | |
And this was then replaced again in 2002. | 0:15:53 | 0:15:56 | |
We've also taken the opportunity to upgrade the electronics, | 0:15:57 | 0:16:01 | |
networking it to telescopes right across Britain and around the world. | 0:16:01 | 0:16:06 | |
It gives the Lovell a new and constantly evolving role. | 0:16:06 | 0:16:10 | |
One of the things we're very interested in at the moment | 0:16:12 | 0:16:14 | |
is a very weird phenomenon called fast radio bursts. | 0:16:14 | 0:16:18 | |
These are very brief, fraction of a second, | 0:16:18 | 0:16:21 | |
strong flashes of radio waves | 0:16:21 | 0:16:23 | |
that appear to come randomly from across the sky. | 0:16:23 | 0:16:25 | |
There's about 20 of them known at the moment, | 0:16:25 | 0:16:27 | |
but we estimate that there's probably as many as 10,000 of them | 0:16:27 | 0:16:31 | |
every single day and we've no idea what they are. | 0:16:31 | 0:16:35 | |
Theories range from neutron stars falling into black holes, | 0:16:35 | 0:16:38 | |
to perhaps rather bizarrely, beams of radio energy | 0:16:38 | 0:16:41 | |
that are being used to accelerate alien spacecraft. | 0:16:41 | 0:16:44 | |
Whatever their true origin, | 0:16:44 | 0:16:46 | |
the fast radio bursts and other similar mysteries will, I'm sure, | 0:16:46 | 0:16:50 | |
mean that the next 60 years of radio astronomy | 0:16:50 | 0:16:52 | |
will be just as exciting as the last. | 0:16:52 | 0:16:55 | |
Happy 60th birthday! | 0:16:59 | 0:17:01 | |
What a marvellous occasion. | 0:17:01 | 0:17:03 | |
I think one of my favourite ones was Michael Bentine discussing | 0:17:03 | 0:17:07 | |
if there were civilisations existing on other planets outside the Earth. | 0:17:07 | 0:17:12 | |
They both agreed there wasn't any then behind them appeared, | 0:17:12 | 0:17:15 | |
I think it was a spaceship from another world. | 0:17:15 | 0:17:19 | |
I thought that was inspirational. | 0:17:19 | 0:17:21 | |
What do you think of the planet Earth? | 0:17:21 | 0:17:24 | |
To be frank, old man, not very much. | 0:17:24 | 0:17:26 | |
Technology has transformed every aspect of life since 1957. | 0:17:30 | 0:17:35 | |
Take television for instance. | 0:17:35 | 0:17:36 | |
This is the kind of camera that would have been used | 0:17:36 | 0:17:39 | |
when The Sky at Night was first broadcast. | 0:17:39 | 0:17:41 | |
Its four prime lenses on the front here allowed you to select | 0:17:41 | 0:17:45 | |
between different shot sizes so there's no need for a zoom. | 0:17:45 | 0:17:49 | |
Compare this magnificent machine to what we use today. | 0:17:49 | 0:17:53 | |
This camera is not only smaller but it's much more sensitive | 0:17:53 | 0:17:56 | |
and so we can use it to shoot the night sky. | 0:17:56 | 0:17:59 | |
If technology has changed television, | 0:17:59 | 0:18:02 | |
that's doubly true for space exploration. | 0:18:02 | 0:18:06 | |
To explain how advances in technology have allowed us | 0:18:06 | 0:18:09 | |
to explore the planet around us, | 0:18:09 | 0:18:11 | |
we asked Dallas Campbell to take us on a cycling tour | 0:18:11 | 0:18:14 | |
of the solar system. | 0:18:14 | 0:18:15 | |
The solar system is a pretty big place. | 0:18:19 | 0:18:21 | |
This scale model just outside York, that's the sun behind me, | 0:18:21 | 0:18:26 | |
gives us an idea of some of the challenges faced | 0:18:26 | 0:18:29 | |
in crossing the huge distances in space | 0:18:29 | 0:18:31 | |
and how actually reaching the planets | 0:18:31 | 0:18:34 | |
has stretched our science and our engineering to the limit. | 0:18:34 | 0:18:37 | |
So I'm setting off to cycle between the planets. | 0:18:39 | 0:18:43 | |
Retracing the steps of my six favourite spacecraft. | 0:18:43 | 0:18:47 | |
The pioneering missions that have taken us | 0:18:48 | 0:18:51 | |
from the surface of the Earth to Pluto and beyond. | 0:18:51 | 0:18:55 | |
When The Sky at Night first transmitted, | 0:18:56 | 0:18:59 | |
the space age hadn't even begun. | 0:18:59 | 0:19:01 | |
The first object that made it into orbit | 0:19:01 | 0:19:03 | |
was the Soviet satellite Sputnik, and that wasn't launched | 0:19:03 | 0:19:07 | |
until six months after that first broadcast. | 0:19:07 | 0:19:10 | |
Sputnik was as simple as a spacecraft can be. | 0:19:11 | 0:19:14 | |
Really nothing more than a radio transmitter | 0:19:14 | 0:19:17 | |
that had been strapped to the top of a rocket. | 0:19:17 | 0:19:20 | |
MAN SPEAKS RUSSIAN | 0:19:20 | 0:19:23 | |
But it makes my list | 0:19:25 | 0:19:26 | |
because it showed that space travel was possible. | 0:19:26 | 0:19:29 | |
Within a matter of months, | 0:19:31 | 0:19:32 | |
the sights of the world's rocket scientists | 0:19:32 | 0:19:35 | |
were set on the other worlds of the solar system. | 0:19:35 | 0:19:37 | |
The first target was obviously the nearest - our own moon - | 0:19:40 | 0:19:44 | |
and actually from here, it looks really, really close to the Earth, | 0:19:44 | 0:19:47 | |
but this whole model, and that includes the size of the planets | 0:19:47 | 0:19:50 | |
and the distance between them, | 0:19:50 | 0:19:52 | |
is built at the scale of around about 575 million to one, | 0:19:52 | 0:19:56 | |
so in the real world, that distance is around about 250,000 miles. | 0:19:56 | 0:20:01 | |
In the 1950s, getting from A to B was a huge technological challenge. | 0:20:01 | 0:20:07 | |
But within just a couple of years, | 0:20:09 | 0:20:11 | |
The Sky at Night was able to report on Soviet success. | 0:20:11 | 0:20:15 | |
In September 1959, | 0:20:16 | 0:20:18 | |
the Russians landed their Lunik 2 on the moon's surface, | 0:20:18 | 0:20:21 | |
and then in October 1959, came that great triumph with Lunik 3, | 0:20:21 | 0:20:27 | |
which actually went round the moon | 0:20:27 | 0:20:29 | |
and photographed that part of the moon's surface | 0:20:29 | 0:20:31 | |
which we can never see from the Earth | 0:20:31 | 0:20:33 | |
because it's always turned away from us. | 0:20:33 | 0:20:35 | |
Well, I for one certainly won't forget those pictures. | 0:20:35 | 0:20:37 | |
But the real triumph came ten years later | 0:20:40 | 0:20:44 | |
with the second mission on our list, Apollo 11. | 0:20:44 | 0:20:48 | |
That's one small step for man, | 0:20:48 | 0:20:51 | |
one giant leap for mankind. | 0:20:51 | 0:20:54 | |
This was one of the defining achievements of the 20th century, | 0:20:54 | 0:20:59 | |
but in retrospect, what is startling | 0:20:59 | 0:21:01 | |
is just how simple the technology was. | 0:21:01 | 0:21:03 | |
The guidance computer on the lunar lander | 0:21:06 | 0:21:08 | |
had less processing power than a modern toaster. | 0:21:08 | 0:21:12 | |
When Neil Armstrong returned to Earth, | 0:21:12 | 0:21:14 | |
he came to The Sky at Night studio. | 0:21:14 | 0:21:16 | |
When you were actually walking about on the moon's surface | 0:21:16 | 0:21:19 | |
and kicking about a certain amount of dust, | 0:21:19 | 0:21:21 | |
did you notice any local colour? | 0:21:21 | 0:21:23 | |
The colour is a puzzling phenomenon on the moon. | 0:21:23 | 0:21:27 | |
Aside from the characteristics that I've already mentioned, | 0:21:27 | 0:21:31 | |
you generally have the impression of being on a desert-like surface | 0:21:31 | 0:21:36 | |
with rather light coloured hues, | 0:21:36 | 0:21:39 | |
yet when you look at the material at close range, as if in your hand, | 0:21:39 | 0:21:45 | |
you find it's a charcoal grey, in fact. | 0:21:45 | 0:21:47 | |
And we were never able to find any things | 0:21:47 | 0:21:49 | |
that were very different from that colour. | 0:21:49 | 0:21:52 | |
Having conquered the moon, it was time to start exploring the planets. | 0:21:54 | 0:21:59 | |
Mars was the main target. | 0:21:59 | 0:22:00 | |
A mere 34 million miles from the Earth at its closest approach, | 0:22:00 | 0:22:05 | |
it's still a long way to go. | 0:22:05 | 0:22:06 | |
Reaching it is hard enough, | 0:22:08 | 0:22:09 | |
but putting landers on the surface | 0:22:09 | 0:22:12 | |
is a feat that has proved consistently difficult. | 0:22:12 | 0:22:14 | |
All in all, we've tried to land 17 spacecraft on Mars, | 0:22:18 | 0:22:22 | |
half of which have failed, | 0:22:22 | 0:22:24 | |
which is understandable when you consider | 0:22:24 | 0:22:26 | |
you're actually trying to send packages | 0:22:26 | 0:22:28 | |
of extremely delicate electronic equipment | 0:22:28 | 0:22:32 | |
across tens of millions of miles of hostile empty space | 0:22:32 | 0:22:35 | |
and then land very carefully on the surface. | 0:22:35 | 0:22:39 | |
One of the main difficulties of landing on Mars | 0:22:39 | 0:22:42 | |
is that the atmosphere is so thin that parachutes are of limited use, | 0:22:42 | 0:22:46 | |
so more ingenious ways of landing have to be devised. | 0:22:46 | 0:22:50 | |
Viking, the first craft to successfully land on Mars, | 0:22:53 | 0:22:56 | |
used a system of retrorockets. | 0:22:56 | 0:22:58 | |
The Opportunity and Spirit rovers touched down in a bouncing air bag. | 0:23:00 | 0:23:04 | |
But the next generation of rovers was too heavy for air bags, | 0:23:05 | 0:23:10 | |
so in 2012 Nasa did this. | 0:23:10 | 0:23:12 | |
Just for sheer ambition and panache, | 0:23:15 | 0:23:18 | |
the third of my favourite spacecraft is the Curiosity Sky Crane, | 0:23:18 | 0:23:22 | |
a triumph of engineering and technological sophistication | 0:23:22 | 0:23:26 | |
designed to lower the Curiosity rover onto the Martian surface. | 0:23:26 | 0:23:30 | |
If getting to Mars is hard, | 0:23:33 | 0:23:34 | |
it's still a lot easier than getting to the outer planets, | 0:23:34 | 0:23:37 | |
the gas and the ice giants. | 0:23:37 | 0:23:39 | |
So the next planet out in the solar system, Jupiter, | 0:23:39 | 0:23:42 | |
is just under a kilometre that way - or, in the real world, | 0:23:42 | 0:23:46 | |
just over half a billion kilometres. | 0:23:46 | 0:23:48 | |
And actually getting to it presents a whole new set of challenges. | 0:23:48 | 0:23:51 | |
And that brings us to the next mission, | 0:23:54 | 0:23:56 | |
and, really, it's my favourite of them all. | 0:23:56 | 0:23:58 | |
Though it's actually two spacecraft, Voyager 1 and 2, | 0:23:58 | 0:24:02 | |
which were both launched in the summer of 1977. | 0:24:02 | 0:24:05 | |
These plutonium powered emissaries | 0:24:07 | 0:24:09 | |
were designed to keep functioning for decades in the depths of space. | 0:24:09 | 0:24:13 | |
They would take advantage of a rare alignment of the planets | 0:24:14 | 0:24:18 | |
that would see them visit Jupiter, Saturn, Uranus | 0:24:18 | 0:24:21 | |
and eventually Neptune over the course of 12 years. | 0:24:21 | 0:24:25 | |
In early 1978, Voyager 1 approached Jupiter. | 0:24:27 | 0:24:31 | |
The world watched in awe as it returned stunning views | 0:24:32 | 0:24:35 | |
of the planet's clouds, storm systems and moons. | 0:24:35 | 0:24:40 | |
It was the first sign of how these two spacecraft | 0:24:40 | 0:24:43 | |
would go on to transform our concept of the outer solar system. | 0:24:43 | 0:24:46 | |
Moving on from Jupiter, the Voyagers visited Saturn in 1980 and '81, | 0:24:51 | 0:24:56 | |
giving us a tantalising glimpse of the magnificent ring systems. | 0:24:56 | 0:25:00 | |
But to really appreciate the Saturn system, | 0:25:03 | 0:25:06 | |
we needed a spacecraft and a camera that could study the rings | 0:25:06 | 0:25:09 | |
in much greater detail. | 0:25:09 | 0:25:11 | |
For that, we had to wait for another 25 years | 0:25:13 | 0:25:16 | |
and the fifth spacecraft on our list, Cassini, | 0:25:16 | 0:25:20 | |
which entered orbit around Saturn in 2004. | 0:25:20 | 0:25:23 | |
The remarkable thing about Cassini is that it was launched 20 years ago | 0:25:26 | 0:25:31 | |
with the technology that was around at the time. | 0:25:31 | 0:25:33 | |
So its cameras, for example, a resolution of about one megapixel, | 0:25:33 | 0:25:37 | |
a fraction of what's on your smartphone, | 0:25:37 | 0:25:38 | |
and yet that technology is incredibly reliable. | 0:25:38 | 0:25:42 | |
It's still sending back the most extraordinary images of Saturn, | 0:25:42 | 0:25:46 | |
its rings and its moons. | 0:25:46 | 0:25:47 | |
The Cassini mission is scheduled to end in September this year. | 0:25:49 | 0:25:52 | |
After a series of closer and closer flybys to the rings, | 0:25:52 | 0:25:55 | |
it is then going to be crashed into the planet. | 0:25:55 | 0:25:58 | |
A glorious, a poignant end | 0:25:58 | 0:26:00 | |
to one of the most transformative missions ever. | 0:26:00 | 0:26:03 | |
After Saturn, missions get pretty thin on the ground, as do planets. | 0:26:09 | 0:26:14 | |
So our next planet is Uranus, | 0:26:14 | 0:26:16 | |
which is twice the distance from the sun as Saturn is. | 0:26:16 | 0:26:19 | |
Now, for me cycling along here it is about 2.5km, | 0:26:19 | 0:26:22 | |
in the real world up there it is about 1.5 billion kilometres. | 0:26:22 | 0:26:26 | |
There's only ever been one spacecraft that's visited it. | 0:26:26 | 0:26:28 | |
In 1986, Voyager 2 flew within 80,000 miles of Uranus. | 0:26:29 | 0:26:35 | |
Well, just about two minutes ago... | 0:26:35 | 0:26:37 | |
..Voyager 2 passed through its closest approach to Uranus. | 0:26:38 | 0:26:42 | |
And three years later it sailed past Neptune. | 0:26:45 | 0:26:49 | |
After Neptune, Voyager 2 just kept on going, | 0:26:49 | 0:26:52 | |
and now both of the Voyager spacecraft are exploring | 0:26:52 | 0:26:55 | |
the very edges of the outer solar system. | 0:26:55 | 0:26:57 | |
And since those first two Voyager missions, | 0:27:01 | 0:27:03 | |
only one other spacecraft has ventured | 0:27:03 | 0:27:06 | |
into the outer solar system. | 0:27:06 | 0:27:08 | |
The sixth and final spacecraft on our list is New Horizons, | 0:27:08 | 0:27:13 | |
the most technologically sophisticated mission | 0:27:13 | 0:27:16 | |
to visit the outer solar system. | 0:27:16 | 0:27:18 | |
Half the size of Voyager, | 0:27:18 | 0:27:19 | |
it made it all the way to Pluto in just nine years. | 0:27:19 | 0:27:23 | |
In July 2015, | 0:27:26 | 0:27:28 | |
Chris and Maggie were in mission control | 0:27:28 | 0:27:30 | |
as New Horizons aimed to pass between Pluto | 0:27:30 | 0:27:33 | |
and the orbit of its moon, Charon. | 0:27:33 | 0:27:35 | |
OK, copy that. | 0:27:37 | 0:27:38 | |
We're in lock with telemetry with... | 0:27:38 | 0:27:40 | |
Yes! | 0:27:40 | 0:27:41 | |
We've got data! | 0:27:41 | 0:27:43 | |
CHEERING AND APPLAUSE | 0:27:43 | 0:27:44 | |
I told you it would be fine! | 0:27:47 | 0:27:49 | |
I wasn't worried! | 0:27:49 | 0:27:50 | |
The jubilation was justified. | 0:27:50 | 0:27:53 | |
Pluto had been thought to be a frozen and dead world, | 0:27:53 | 0:27:56 | |
but the data that New Horizons returned showed that, | 0:27:56 | 0:27:59 | |
against all expectations, | 0:27:59 | 0:28:01 | |
this tiny world at the edge of the solar system | 0:28:01 | 0:28:04 | |
was alive with active geology. | 0:28:04 | 0:28:07 | |
Blimey! | 0:28:08 | 0:28:09 | |
Here we are. Finally, we make it to Pluto. | 0:28:11 | 0:28:14 | |
Look how tiny Pluto is. And that's one of its moons, Charon. | 0:28:14 | 0:28:18 | |
Now, on my scale, Pluto to the Earth, about 10km. | 0:28:18 | 0:28:22 | |
And in reality it would be round about 6 billion kilometres. | 0:28:22 | 0:28:26 | |
It's amazing to think in the last 60 years | 0:28:26 | 0:28:28 | |
we've developed this technology that's allowed us to explore | 0:28:28 | 0:28:32 | |
pretty much the whole of the solar system, | 0:28:32 | 0:28:34 | |
from the moment that Sputnik first left the Earth | 0:28:34 | 0:28:37 | |
all the way to the New Horizons' mission to Pluto and beyond. | 0:28:37 | 0:28:41 | |
And the extraordinary thing is that every step of the way | 0:28:42 | 0:28:45 | |
along that history timeline, | 0:28:45 | 0:28:46 | |
we have been surprised, we have learned something new. | 0:28:46 | 0:28:49 | |
Nothing is as we thought it would be. | 0:28:49 | 0:28:52 | |
And who knows what our technology will be like | 0:28:52 | 0:28:55 | |
in the next 60 years and what we might find out? | 0:28:55 | 0:28:58 | |
Of course, we've sent many more than six missions into the solar system. | 0:29:02 | 0:29:06 | |
This graphic represents every single probe | 0:29:08 | 0:29:11 | |
that we've sent to the planets, | 0:29:11 | 0:29:13 | |
and between them they have revolutionised our understanding | 0:29:13 | 0:29:16 | |
of the solar system. | 0:29:16 | 0:29:18 | |
60 years ago, we thought there were nine planets orbited by 30 moons. | 0:29:18 | 0:29:24 | |
Now we have just eight planets but over 180 moons. | 0:29:24 | 0:29:28 | |
And it's the moons that have been the greatest surprise, | 0:29:29 | 0:29:32 | |
particularly the icy moons of the outer planets. | 0:29:32 | 0:29:35 | |
Well, I'm joined by Michele Dougherty, | 0:29:38 | 0:29:39 | |
an explorer of the outer solar system - | 0:29:39 | 0:29:41 | |
particularly with Cassini, the mission to Saturn. | 0:29:41 | 0:29:44 | |
I think the thing that strikes me is wherever we've been, | 0:29:44 | 0:29:47 | |
we've been surprised, and maybe nowhere more so than Saturn. | 0:29:47 | 0:29:50 | |
Can you tell us about the exploration of Saturn? | 0:29:50 | 0:29:52 | |
We were launched in 1997, we took a long time to get there, | 0:29:52 | 0:29:55 | |
got there in July 2004, | 0:29:55 | 0:29:58 | |
and we've essentially spent the last 13 years orbiting around Saturn. | 0:29:58 | 0:30:02 | |
The biggest surprise was linked to one of its small moons, Enceladus. | 0:30:02 | 0:30:07 | |
What are we looking at here? | 0:30:07 | 0:30:08 | |
It's a very small world, its diameter is 500km. | 0:30:08 | 0:30:11 | |
We would have long thought if from when it first formed | 0:30:11 | 0:30:14 | |
there were to be some kind of heat in the interior, | 0:30:14 | 0:30:16 | |
but over time that dies away, so we thought it was dead. | 0:30:16 | 0:30:19 | |
But what we are looking at here is a very young surface. | 0:30:19 | 0:30:23 | |
You can see there are some craters on the surface, | 0:30:23 | 0:30:25 | |
but there aren't as many as you would expect. | 0:30:25 | 0:30:28 | |
But I think the most exciting of all are these blue cracks | 0:30:28 | 0:30:32 | |
at the South Pole. | 0:30:32 | 0:30:33 | |
The imaging team on Cassini calls them tiger stripes, | 0:30:33 | 0:30:36 | |
and it was from these cracks | 0:30:36 | 0:30:38 | |
that we found there was this plume of water vapour | 0:30:38 | 0:30:41 | |
coming off from the South Pole. | 0:30:41 | 0:30:42 | |
In fact, we've got an image of the plume. | 0:30:42 | 0:30:44 | |
You can see it better. This is the night side of Enceladus, | 0:30:44 | 0:30:47 | |
what we were just looking at is this surface, | 0:30:47 | 0:30:50 | |
and then there's this jet of material. | 0:30:50 | 0:30:52 | |
Absolutely. If you look really closely, | 0:30:52 | 0:30:54 | |
you can see there are individual plumes | 0:30:54 | 0:30:56 | |
-coming out of the different... -Separate fountains. | 0:30:56 | 0:30:58 | |
It's not just water vapour. | 0:30:58 | 0:30:59 | |
There's organic material, there is dust. | 0:30:59 | 0:31:03 | |
There's an instrument on board, the Ion Neutral Mass Spectrometer, | 0:31:03 | 0:31:07 | |
that can actually taste what's in the plume, | 0:31:07 | 0:31:09 | |
and it found that there was ammonia. | 0:31:09 | 0:31:11 | |
And we found that out, actually, on one of the really close flybys. | 0:31:11 | 0:31:14 | |
It was 25km above the surface. | 0:31:14 | 0:31:16 | |
So you flew straight through the plume? | 0:31:16 | 0:31:18 | |
We flew straight through the plume. | 0:31:18 | 0:31:20 | |
We won't do that again, | 0:31:20 | 0:31:22 | |
because the density of the plume is so strong | 0:31:22 | 0:31:24 | |
that the spacecraft almost began to actually tumble, and so they said, | 0:31:24 | 0:31:28 | |
"No, we aren't going to do that again." | 0:31:28 | 0:31:30 | |
So this is a small moon in the cold outer solar system | 0:31:30 | 0:31:33 | |
with liquid water? | 0:31:33 | 0:31:34 | |
Yes. It's weird, isn't it? | 0:31:34 | 0:31:35 | |
It's very strange. So why is there so much water there? | 0:31:35 | 0:31:39 | |
How is it liquid? | 0:31:39 | 0:31:40 | |
What we think is happening is tidal forces, | 0:31:40 | 0:31:43 | |
as Enceladus is orbiting around Saturn, | 0:31:43 | 0:31:46 | |
on some parts of the orbit, it's slightly closer to Saturn | 0:31:46 | 0:31:49 | |
than on others, and so the gravitational force is stronger, | 0:31:49 | 0:31:52 | |
and so that's where the tidal forces are coming from. | 0:31:52 | 0:31:54 | |
So it's squeezed and then stretched by its orbit? | 0:31:54 | 0:31:56 | |
Absolutely. | 0:31:56 | 0:31:58 | |
I think from my perspective, the most exciting part | 0:31:58 | 0:32:00 | |
is the fact that, you know, people are very interested | 0:32:00 | 0:32:02 | |
about potential habitability. | 0:32:02 | 0:32:03 | |
You know, you need four things for life to be able to form. | 0:32:03 | 0:32:07 | |
You need liquid water... | 0:32:07 | 0:32:08 | |
-Got that. -You need organic material... | 0:32:08 | 0:32:10 | |
-You've seen that too. -You need a heat source... | 0:32:10 | 0:32:13 | |
Something's got to be heating this up. | 0:32:13 | 0:32:14 | |
And it needs to be stable over a period of time. | 0:32:14 | 0:32:17 | |
That's what we're not sure about with Enceladus. | 0:32:17 | 0:32:19 | |
So whether we might have got lucky, maybe we saw something that... | 0:32:19 | 0:32:22 | |
-This is a recent phenomenon? -Absolutely. -And it's not just here, | 0:32:22 | 0:32:25 | |
we've seen this sort of thing at Jupiter as well? | 0:32:25 | 0:32:28 | |
There's the Galileo probe to Jupiter. | 0:32:28 | 0:32:30 | |
Tell us about its explorations of the moons? | 0:32:30 | 0:32:32 | |
What the Galileo spacecraft did | 0:32:32 | 0:32:33 | |
is it orbited around Jupiter for four years. | 0:32:33 | 0:32:36 | |
What they found is on some of the close flybys of the moons, | 0:32:36 | 0:32:39 | |
in particular Europa... | 0:32:39 | 0:32:41 | |
-So this is Europa, and it looks kind of similar. -It does. | 0:32:41 | 0:32:43 | |
You've got cracks and ice and, I guess, no craters again. | 0:32:43 | 0:32:48 | |
I think the difference with Europa | 0:32:48 | 0:32:50 | |
is that they look as if they're icebergs. | 0:32:50 | 0:32:53 | |
We think that there are some very thin surface regions, | 0:32:53 | 0:32:58 | |
because if you have a close-up view of Europa, and I think... | 0:32:58 | 0:33:01 | |
Yes, let's pull one up. | 0:33:01 | 0:33:02 | |
To me, it looks like it's almost as if you're sitting in an aeroplane, | 0:33:02 | 0:33:06 | |
flying over Greenland and you look out of the window | 0:33:06 | 0:33:08 | |
and you see the ice shelf, | 0:33:08 | 0:33:10 | |
and it's almost as if you can see an iceberg breaking off | 0:33:10 | 0:33:12 | |
and moving on a slushy surface. | 0:33:12 | 0:33:16 | |
So we think there might be regions on the Europa surface | 0:33:16 | 0:33:19 | |
where it's really... The ice crust is very thin. | 0:33:19 | 0:33:22 | |
And that's one of the reasons we want to go back, | 0:33:22 | 0:33:25 | |
and so the Juice mission is going to go to Jupiter, | 0:33:25 | 0:33:28 | |
and there's a Nasa mission called Europa Clipper, | 0:33:28 | 0:33:30 | |
which is going to go to Europa. | 0:33:30 | 0:33:33 | |
And thinking back over the 60 years that Sky at Night's been around, | 0:33:33 | 0:33:36 | |
how big a change has there been? | 0:33:36 | 0:33:38 | |
It's a huge change. | 0:33:38 | 0:33:39 | |
No-one thought there would be liquid water oceans | 0:33:39 | 0:33:41 | |
in the outer solar system. It's too cold. | 0:33:41 | 0:33:43 | |
And so that's been a sea change | 0:33:43 | 0:33:45 | |
as far as the search for potential habitability. | 0:33:45 | 0:33:48 | |
We now know you can get most of the conditions that you need | 0:33:48 | 0:33:52 | |
in our outer solar system, | 0:33:52 | 0:33:54 | |
and potentially outside of our solar system. | 0:33:54 | 0:33:56 | |
There are plenty of other places to look in our solar system as well. | 0:33:56 | 0:33:59 | |
Absolutely, that's right. | 0:33:59 | 0:34:00 | |
Hello, and congratulations to the BBC's Sky at Night | 0:34:08 | 0:34:11 | |
on your 60th birthday. | 0:34:11 | 0:34:13 | |
Thank you so much for bringing the wonders of the universe | 0:34:13 | 0:34:15 | |
into our living rooms | 0:34:15 | 0:34:17 | |
and for inspiring me and so many others to look up to the stars. | 0:34:17 | 0:34:20 | |
Amateur observing has always been an integral part of the show, | 0:34:24 | 0:34:28 | |
but even here things have changed. | 0:34:28 | 0:34:30 | |
So we set Pete Lawrence and a group of amateur observers a challenge - | 0:34:30 | 0:34:34 | |
to see if they could capture the night sky | 0:34:34 | 0:34:36 | |
using the technology of the 1950s. | 0:34:36 | 0:34:39 | |
Although the technology used to view the night sky | 0:34:40 | 0:34:42 | |
may have changed over the last 60 years, | 0:34:42 | 0:34:45 | |
amateur astronomers have always had to contend | 0:34:45 | 0:34:48 | |
with a very British problem. | 0:34:48 | 0:34:49 | |
..general direction of the moon, frankly, | 0:34:49 | 0:34:51 | |
I can't see a single star at the moment. | 0:34:51 | 0:34:53 | |
It's totally obscured. | 0:34:53 | 0:34:55 | |
We were hoping to see Vega, the star straight above our heads, | 0:34:55 | 0:34:59 | |
but even that's gone now. | 0:34:59 | 0:35:01 | |
No, we've got to abandon it for a moment or two. | 0:35:01 | 0:35:03 | |
We are blacked out. | 0:35:03 | 0:35:04 | |
These days, we have computer-controlled telescopes | 0:35:06 | 0:35:09 | |
and high sensitivity cameras to capture images of the sky. | 0:35:09 | 0:35:14 | |
But have we lost some of the magic of stargazing as a result? | 0:35:14 | 0:35:18 | |
Tonight I've gathered a group of astronomers | 0:35:20 | 0:35:22 | |
under the impressive Lovell Telescope at Jodrell Bank, | 0:35:22 | 0:35:26 | |
and we're going to see what amateur astronomy was like, 1950s style. | 0:35:26 | 0:35:30 | |
One of the key things I've noticed | 0:35:30 | 0:35:33 | |
is that there's quite a big difference in type of kit we use. | 0:35:33 | 0:35:37 | |
So, Richard, I've been admiring this scope from across the field, | 0:35:37 | 0:35:40 | |
it's beautiful. How old is it? | 0:35:40 | 0:35:41 | |
This is nearly 50 years old. It's a 1971. | 0:35:41 | 0:35:44 | |
With an open frame like this you can see everything inside, can't you? | 0:35:44 | 0:35:47 | |
You can see the primary mirror at the bottom, | 0:35:47 | 0:35:49 | |
which, actually, looks very clean. | 0:35:49 | 0:35:51 | |
Light from the object in the sky | 0:35:51 | 0:35:52 | |
bounces off the primary mirror at the bottom, | 0:35:52 | 0:35:55 | |
focusing it via the secondary mirror into the eyepiece. | 0:35:55 | 0:35:59 | |
This kind of telescope works just as well with an open frame. | 0:35:59 | 0:36:02 | |
And what I've really noticed about it is how heavily engineered it is | 0:36:04 | 0:36:07 | |
as well, this mount looks... | 0:36:07 | 0:36:09 | |
It's almost overkill, very heavy and very solid, | 0:36:09 | 0:36:11 | |
and it gives it perfect balance. | 0:36:11 | 0:36:14 | |
It does move beautifully. | 0:36:14 | 0:36:15 | |
That move's so smooth. Isn't that gorgeous? | 0:36:15 | 0:36:18 | |
Thank you very much for showing me this. | 0:36:18 | 0:36:20 | |
I wish it was clear, because I'd love to look through it. | 0:36:20 | 0:36:23 | |
Wait a minute, there's some kind of a break over there. | 0:36:23 | 0:36:25 | |
Can you see it? Look, over there. | 0:36:25 | 0:36:28 | |
-Something... -I can't see anything in it, though. | 0:36:28 | 0:36:31 | |
No. | 0:36:31 | 0:36:32 | |
In the '50s, even when you could see something, | 0:36:32 | 0:36:36 | |
photographing it was complex... | 0:36:36 | 0:36:38 | |
and expensive. | 0:36:38 | 0:36:40 | |
So a lot of amateur astronomers turned to sketching. | 0:36:40 | 0:36:44 | |
Luckily the night before had been beautifully clear | 0:36:44 | 0:36:47 | |
and some of our amateurs were out looking at the moon. | 0:36:47 | 0:36:50 | |
So, Paul, you had a beautifully clear night | 0:36:50 | 0:36:53 | |
and you did some sketching? | 0:36:53 | 0:36:54 | |
-I did. -I can recognise that straight away. | 0:36:54 | 0:36:56 | |
You've three very distinctive craters, that's Theophilus, | 0:36:56 | 0:37:00 | |
Cyrillus and Catharina. | 0:37:00 | 0:37:01 | |
-Yes. -What I love about your sketches | 0:37:01 | 0:37:04 | |
is the way you've done them on the black paper. | 0:37:04 | 0:37:06 | |
That's come out so well. | 0:37:06 | 0:37:07 | |
It's much easier to see as well at night with a little light. | 0:37:07 | 0:37:11 | |
It took quite a long time to do that, at least an hour. | 0:37:11 | 0:37:14 | |
If I compare it with a photo I took last night, you can definitely see. | 0:37:14 | 0:37:17 | |
You've got Theophilus up here | 0:37:17 | 0:37:18 | |
with its central mountain peak very clearly, | 0:37:18 | 0:37:21 | |
and you've got Cyrillus underneath | 0:37:21 | 0:37:23 | |
with the two peaks in the centre, there. | 0:37:23 | 0:37:25 | |
You've rendered that really well. | 0:37:25 | 0:37:27 | |
Thank you very much. | 0:37:27 | 0:37:28 | |
At their very best, | 0:37:28 | 0:37:29 | |
amateur sketches are every bit as useful as photos. | 0:37:29 | 0:37:33 | |
These ones from the '30s and '40s | 0:37:33 | 0:37:36 | |
show a ring plane crossing of Saturn | 0:37:36 | 0:37:39 | |
and the surface of Mars in incredible detail. | 0:37:39 | 0:37:43 | |
Just a few minutes to try and get... | 0:37:43 | 0:37:45 | |
The moon is just being awkward. | 0:37:45 | 0:37:48 | |
The moon is just being awkward at the moment, I'm afraid. | 0:37:48 | 0:37:50 | |
Donna, you have performed something of a miracle this evening, | 0:37:50 | 0:37:54 | |
and you actually managed to get a sketch of the moon. | 0:37:54 | 0:37:56 | |
Yes. It was very fleeting, but it was there. | 0:37:56 | 0:37:59 | |
I can recognise that immediately as the Mare Crisium. | 0:37:59 | 0:38:02 | |
It was very hazy, but I was using binoculars. | 0:38:02 | 0:38:05 | |
I found myself actually observing as opposed to just looking. | 0:38:05 | 0:38:09 | |
Do you know, that is really the essence of what you've done here, | 0:38:09 | 0:38:14 | |
and that's... I think that's something which, | 0:38:14 | 0:38:17 | |
to a certain degree, we've lost in amateur astronomy. | 0:38:17 | 0:38:20 | |
Because looking through the eyepiece to sketch something, | 0:38:20 | 0:38:23 | |
you really do have to look at it. | 0:38:23 | 0:38:26 | |
It did make me concentrate, I have to say. | 0:38:26 | 0:38:27 | |
I did actually concentrate. | 0:38:27 | 0:38:29 | |
-It's a wonderful feeling, isn't it? -Oh, yes. | 0:38:29 | 0:38:30 | |
Although tonight the sky might have been typically disappointing, | 0:38:33 | 0:38:37 | |
I've been powerfully reminded of the romance of sketching | 0:38:37 | 0:38:40 | |
and how it makes the act of observing | 0:38:40 | 0:38:43 | |
a more intense and involving experience. | 0:38:43 | 0:38:45 | |
So if you've got pen and paper at home, why not give it a go yourself? | 0:38:49 | 0:38:52 | |
Now, to find out what's happening in the April and May night sky, | 0:38:52 | 0:38:56 | |
why not pop along to our website and look at our latest star guide? | 0:38:56 | 0:39:00 | |
Also on the website, you can find our viewers' gallery, | 0:39:03 | 0:39:07 | |
showcasing some of the finest images of the night sky | 0:39:07 | 0:39:10 | |
captured by Sky at Night viewers using today's technology. | 0:39:10 | 0:39:14 | |
Happy birthday, Sky at Night! | 0:39:21 | 0:39:23 | |
I watched you when I was a kid in England, | 0:39:23 | 0:39:26 | |
all the nice stuff got me into space, | 0:39:26 | 0:39:29 | |
and then I got involved in Voyager, Galileo, Cassini, and now Juno! | 0:39:29 | 0:39:34 | |
Over the past 60 years there's been a transformation | 0:39:38 | 0:39:41 | |
in our understanding of the history of the universe and how it works. | 0:39:41 | 0:39:45 | |
What we call cosmology. | 0:39:45 | 0:39:47 | |
We asked Jim Al-Khalili to explain more. | 0:39:47 | 0:39:49 | |
For thousands of years astronomy was a descriptive science. | 0:39:57 | 0:40:01 | |
Astronomers made ever more detailed maps of the night sky, | 0:40:01 | 0:40:06 | |
but they seldom addressed fundamental questions. | 0:40:06 | 0:40:09 | |
What was a star, a galaxy, a planet? | 0:40:10 | 0:40:15 | |
How did the universe work? | 0:40:15 | 0:40:18 | |
But then, unexpectedly, at the beginning of the last century, | 0:40:18 | 0:40:22 | |
this all changed. | 0:40:22 | 0:40:24 | |
In the early 20th century, | 0:40:26 | 0:40:28 | |
the scientific establishment was rocked by the emergence | 0:40:28 | 0:40:30 | |
of Einstein's theories of relativity | 0:40:30 | 0:40:33 | |
and the bizarre theories of quantum mechanics. | 0:40:33 | 0:40:35 | |
And they began to realise that with this new physics, | 0:40:35 | 0:40:38 | |
not only could they explain phenomena here on Earth, | 0:40:38 | 0:40:41 | |
but that these theories might apply on an epic scale | 0:40:41 | 0:40:45 | |
across the universe as a whole. | 0:40:45 | 0:40:46 | |
And one of the first projects was to try to use this new science | 0:40:49 | 0:40:53 | |
to explain how the universe actually began. | 0:40:53 | 0:40:58 | |
By the 1940s, two schools of thought had developed, | 0:40:58 | 0:41:02 | |
the Big Bang and the Steady State. | 0:41:02 | 0:41:05 | |
The Big Bang theory said that the entire universe | 0:41:05 | 0:41:07 | |
was formed at a single moment. | 0:41:07 | 0:41:09 | |
A cataclysmic explosion from an infinitesimally small point, | 0:41:09 | 0:41:14 | |
marking the birth of space and time, and it's been expanding ever since. | 0:41:14 | 0:41:19 | |
Whereas the Steady State theory said that while the universe | 0:41:19 | 0:41:22 | |
has been constantly expanding, | 0:41:22 | 0:41:24 | |
new matter is being created all the time, everywhere, | 0:41:24 | 0:41:28 | |
always the same, nothing changing, no beginning or end. | 0:41:28 | 0:41:31 | |
In 1957, when The Sky at Night was first broadcast, | 0:41:33 | 0:41:36 | |
this argument over which theory was right was still raging. | 0:41:36 | 0:41:40 | |
Patrick Moore returned many times to this theme over the next few years. | 0:41:41 | 0:41:46 | |
And the one inescapable fact, at least I think it is, | 0:41:46 | 0:41:49 | |
is that you and me and your television set | 0:41:49 | 0:41:52 | |
and the kitchen sink and Aunt Emily, they actually exist. | 0:41:52 | 0:41:55 | |
So the matter making up ourselves must have come from somewhere. | 0:41:55 | 0:41:59 | |
There are some astronomers who believe | 0:41:59 | 0:42:01 | |
in what's known as the Steady State theory, | 0:42:01 | 0:42:03 | |
that the universe has always existed and will exist forever. | 0:42:03 | 0:42:08 | |
But the problem was the Steady State and the Big Bang theories | 0:42:08 | 0:42:12 | |
remained pure conjecture, | 0:42:12 | 0:42:15 | |
because there was no measurable evidence | 0:42:15 | 0:42:17 | |
that would tell which was right and which was wrong. | 0:42:17 | 0:42:21 | |
Then in 1964, an accidental discovery changed all that. | 0:42:21 | 0:42:27 | |
Two young astronomers, Arno Penzias and Robert Wilson, | 0:42:28 | 0:42:32 | |
had just inherited a strange looking radio telescope, the horn antenna. | 0:42:32 | 0:42:37 | |
But this unlikely telescope would surprise everyone | 0:42:37 | 0:42:41 | |
and reveal how the universe actually started. | 0:42:41 | 0:42:44 | |
The horn antenna was built to look for very specific radio signatures - | 0:42:50 | 0:42:55 | |
microwaves. | 0:42:55 | 0:42:57 | |
Penzias and Wilson tweaked it to make it super sensitive | 0:42:57 | 0:43:01 | |
so they could study the Milky Way. | 0:43:01 | 0:43:03 | |
But then wherever they looked in the sky, | 0:43:03 | 0:43:06 | |
they could hear a very annoying hiss | 0:43:06 | 0:43:08 | |
which they simply couldn't get rid of. | 0:43:08 | 0:43:11 | |
HISSING | 0:43:11 | 0:43:15 | |
Eventually, they realised that this hiss | 0:43:15 | 0:43:17 | |
coming from everywhere in the universe could only be one thing. | 0:43:17 | 0:43:22 | |
It was actually the faint remnant of the Big Bang itself. | 0:43:22 | 0:43:27 | |
The discovery of this hiss, the cosmic microwave background, | 0:43:33 | 0:43:36 | |
by Penzias and Wilson in 1964, | 0:43:36 | 0:43:39 | |
proved, conclusively, that the Big Bang theory was correct. | 0:43:39 | 0:43:43 | |
And it told us something else too, | 0:43:43 | 0:43:45 | |
that astronomy is much more than just a descriptive science. | 0:43:45 | 0:43:49 | |
What's more, using maths and physics, | 0:43:49 | 0:43:52 | |
we can really understand how the universe was made - | 0:43:52 | 0:43:56 | |
where it came from, how it works and how it might possibly end. | 0:43:56 | 0:44:00 | |
The confirmation of the Big Bang by the cosmic microwave background | 0:44:03 | 0:44:07 | |
gave astrophysics a massive confidence boost | 0:44:07 | 0:44:11 | |
and it led to a burst of new and astonishing ideas and discoveries. | 0:44:11 | 0:44:16 | |
One of the insights of this new science | 0:44:19 | 0:44:22 | |
was the idea that gravity plays a key role | 0:44:22 | 0:44:24 | |
in the story of the universe. | 0:44:24 | 0:44:26 | |
As well as describing the orbits of planets around the sun | 0:44:26 | 0:44:29 | |
and the motion of stars within galaxies, | 0:44:29 | 0:44:32 | |
scientists also began to understand that it works within stars, | 0:44:32 | 0:44:36 | |
crushing them together to create the conditions for nuclear reactions | 0:44:36 | 0:44:39 | |
that make stars shine so fiercely. | 0:44:39 | 0:44:42 | |
But their theories also predicted that, on a cosmic scale, | 0:44:42 | 0:44:46 | |
gravity would produce unexpected and bizarre outcomes. | 0:44:46 | 0:44:50 | |
For instance, as stars ended their lives, | 0:44:55 | 0:44:58 | |
the theoreticians suggested they | 0:44:58 | 0:45:00 | |
would continue to collapse under gravity, | 0:45:00 | 0:45:02 | |
crushing their cores until they were just a few kilometres across at | 0:45:02 | 0:45:07 | |
unbelievable densities. | 0:45:07 | 0:45:08 | |
It seemed the stuff of science fiction. | 0:45:11 | 0:45:13 | |
Then in November 1967, and using a rather underwhelming radio antenna, | 0:45:17 | 0:45:22 | |
more like a clothesline than something like this, | 0:45:22 | 0:45:25 | |
a young research scientist by the name of Jocelyn Bell | 0:45:25 | 0:45:28 | |
saw something strange. | 0:45:28 | 0:45:30 | |
In her data was a pulsing radio signal | 0:45:30 | 0:45:32 | |
incredibly fast and incredibly regular. | 0:45:32 | 0:45:36 | |
At first it was genuinely thought that this might be a signal from an | 0:45:36 | 0:45:40 | |
alien world. In fact it was dubbed LGM for little green men. | 0:45:40 | 0:45:45 | |
But it was soon realised that these so-called pulsars were in fact | 0:45:45 | 0:45:49 | |
superdense stars or neutron stars | 0:45:49 | 0:45:51 | |
that physicists had already predicted. | 0:45:51 | 0:45:54 | |
There was another incredible prediction too, | 0:45:58 | 0:46:01 | |
perhaps gravity could crush stars so powerfully | 0:46:01 | 0:46:04 | |
that even light couldn't escape. | 0:46:04 | 0:46:06 | |
These were called black holes. | 0:46:06 | 0:46:09 | |
Over the next few years, | 0:46:14 | 0:46:16 | |
pulsars and black holes shifted from pure speculation | 0:46:16 | 0:46:20 | |
to astronomical orthodoxy. | 0:46:20 | 0:46:22 | |
And it seemed as though the universe was finally beginning to | 0:46:23 | 0:46:27 | |
make some sense. | 0:46:27 | 0:46:28 | |
But then in the mid-1970s, | 0:46:30 | 0:46:33 | |
a new series of observations threatened to turn | 0:46:33 | 0:46:35 | |
everything we thought we knew upside down. | 0:46:35 | 0:46:39 | |
In the USA, scientists led by astrophysicist Vera Rubin, | 0:46:44 | 0:46:49 | |
were studying huge spiral galaxies deep in space. | 0:46:49 | 0:46:52 | |
Rubin had initially thought that | 0:46:54 | 0:46:56 | |
just like the outer planets of the solar system, | 0:46:56 | 0:46:59 | |
the outer stars of the galaxy should be orbiting around | 0:46:59 | 0:47:03 | |
more slowly than the inner stars, but they weren't. | 0:47:03 | 0:47:07 | |
It was as though they weren't obeying the laws of gravity. | 0:47:07 | 0:47:10 | |
Her crazy explanation was that the spiral arms of the galaxy contained | 0:47:10 | 0:47:15 | |
a new kind of material called dark matter. | 0:47:15 | 0:47:19 | |
This invisible material provided the extra gravity needed | 0:47:19 | 0:47:24 | |
to control the motion of the stars. | 0:47:24 | 0:47:26 | |
We just couldn't see it. | 0:47:28 | 0:47:30 | |
Patrick Moore himself sometimes found dark matter hard to stomach. | 0:47:30 | 0:47:34 | |
Well, we can see the effect of dark matter where they have a | 0:47:34 | 0:47:37 | |
gravitational effect and these seem to be definite. | 0:47:37 | 0:47:39 | |
But what is dark matter? | 0:47:39 | 0:47:42 | |
Is it something we can't understand? | 0:47:42 | 0:47:44 | |
More a fudge, isn't it? | 0:47:44 | 0:47:46 | |
Well, you can call it a fudge but it turns out that it's incredibly | 0:47:46 | 0:47:50 | |
-consistent with all our observations. -Really? | 0:47:50 | 0:47:53 | |
And there was to be more, too. | 0:47:53 | 0:47:55 | |
In the 1990s, as scientists peered deeper and deeper into space, | 0:47:55 | 0:47:59 | |
they noticed another inconsistency. | 0:47:59 | 0:48:02 | |
Sure the universe was expanding but it seemed to be expanding quicker | 0:48:03 | 0:48:08 | |
and quicker. To explain this, theorists came up with the idea of | 0:48:08 | 0:48:13 | |
dark energy, | 0:48:13 | 0:48:14 | |
a mysterious something that pervaded the whole universe and that was | 0:48:14 | 0:48:19 | |
pushing it apart ever more rapidly. | 0:48:19 | 0:48:21 | |
As yet, there is no material evidence | 0:48:24 | 0:48:27 | |
of dark matter or dark energy but if they do exist, | 0:48:27 | 0:48:31 | |
scientists predict that they make up about 95% of the known universe, | 0:48:31 | 0:48:37 | |
meaning almost everything out there in space is a mystery. | 0:48:37 | 0:48:41 | |
As The Sky at Night celebrates its 60th, | 0:48:46 | 0:48:49 | |
it seems as though the universe is more fascinating and more mysterious | 0:48:49 | 0:48:54 | |
than ever before and everything we | 0:48:54 | 0:48:56 | |
thought we knew is still up for grabs. | 0:48:56 | 0:48:58 | |
And one thing is for sure - | 0:48:59 | 0:49:01 | |
the next 60 years is likely to be just as interesting. | 0:49:01 | 0:49:05 | |
Hello, Sky at Night, | 0:49:13 | 0:49:14 | |
well done on the signals | 0:49:14 | 0:49:15 | |
from your very first programme | 0:49:15 | 0:49:17 | |
now having travelled | 0:49:17 | 0:49:18 | |
60 light years into the universe. | 0:49:18 | 0:49:20 | |
Congratulations and let's hope you | 0:49:20 | 0:49:22 | |
haven't started an interplanetary war. | 0:49:22 | 0:49:25 | |
All that cosmology, the Big Bang, | 0:49:28 | 0:49:30 | |
the physics of black holes and pulsars. | 0:49:30 | 0:49:33 | |
It all seems rather distant, | 0:49:33 | 0:49:36 | |
but sometimes you can find a little bit of a distant universe right here | 0:49:36 | 0:49:39 | |
on earth which brings us back to the black diamonds, the carbonados. | 0:49:39 | 0:49:44 | |
To find out more about them, we've been joined by diamond expert, | 0:49:45 | 0:49:49 | |
Adrian Jones. | 0:49:49 | 0:49:51 | |
Adrian, let me give this back before I lose it. | 0:49:51 | 0:49:54 | |
Can you tell me, how does a carbonado differ | 0:49:54 | 0:49:56 | |
from a standard diamond? | 0:49:56 | 0:49:58 | |
-They look different. -They do. | 0:49:58 | 0:49:59 | |
Especially when you look down a microscope. | 0:49:59 | 0:50:02 | |
Have a quick look and see what you can see. | 0:50:02 | 0:50:04 | |
They look quite grey, there's some shiny bits but one of the strange | 0:50:04 | 0:50:08 | |
things is if they've got lots of holes all over them, | 0:50:08 | 0:50:10 | |
which is a bit unusual, isn't it? It looks porous. | 0:50:10 | 0:50:13 | |
They are, exactly. They look a little bit like pumice. | 0:50:13 | 0:50:15 | |
And the little holes inside them are baffling | 0:50:15 | 0:50:17 | |
because diamonds are formed at very high | 0:50:17 | 0:50:20 | |
pressure and high temperature and normally when you make a very high | 0:50:20 | 0:50:23 | |
pressure, you squeeze things. | 0:50:23 | 0:50:24 | |
It's very hard to imagine how the | 0:50:24 | 0:50:26 | |
holes are formed or remain in the diamond. | 0:50:26 | 0:50:28 | |
Yes. So how do we think they were formed? | 0:50:28 | 0:50:32 | |
One explanation would be that they have been formed at extremely high | 0:50:32 | 0:50:35 | |
temperatures, perhaps high enough to melt the diamond, | 0:50:35 | 0:50:38 | |
so there's a possibility of liquid diamond and there's also the | 0:50:38 | 0:50:41 | |
possibility of vapour diamond making some little holes. | 0:50:41 | 0:50:46 | |
You said there liquid diamond. I didn't know that was possible. | 0:50:46 | 0:50:50 | |
It's certainly extraordinary and not possible on the Earth today. | 0:50:50 | 0:50:53 | |
-Yes. -This is one of the main lines of evidence these could be | 0:50:53 | 0:50:56 | |
-extraterrestrial. -So, if they weren't formed on Earth, | 0:50:56 | 0:50:58 | |
where did they originate from? | 0:50:58 | 0:51:00 | |
So, you need something pretty extraordinary, | 0:51:00 | 0:51:02 | |
something rich in carbon because diamonds are made from carbon. | 0:51:02 | 0:51:05 | |
Pressures, perhaps, as great as twice the pressure at the centre of | 0:51:05 | 0:51:08 | |
the earth, temperatures greater potentially than | 0:51:08 | 0:51:11 | |
-the surface of the sun. -Oh, wow! | 0:51:11 | 0:51:13 | |
One of the few places in the universe where you'd find those | 0:51:15 | 0:51:18 | |
conditions is in heart of white dwarfs - | 0:51:18 | 0:51:21 | |
the collapsed remnants of stars like our sun. | 0:51:21 | 0:51:23 | |
As these stars undergo gravitational collapse at the end of their lives, | 0:51:30 | 0:51:34 | |
they generate the sort of temperatures and pressures within | 0:51:34 | 0:51:37 | |
their carbon-rich cores that would be required to | 0:51:37 | 0:51:40 | |
create carbonado diamonds. | 0:51:40 | 0:51:42 | |
If that white dwarf was then ruptured, | 0:51:44 | 0:51:46 | |
it would be broken into diamond-rich asteroids. | 0:51:46 | 0:51:49 | |
It's thought that all the carbonados on earth may have been delivered by | 0:51:50 | 0:51:54 | |
just one of those asteroids. | 0:51:54 | 0:51:57 | |
So, these carbonados from Brazil and | 0:51:57 | 0:51:59 | |
we know they are found only in Brazil | 0:51:59 | 0:52:01 | |
and Africa, so they probably arrived as a single asteroid made of | 0:52:01 | 0:52:06 | |
carbonado which broke up and | 0:52:06 | 0:52:08 | |
collided with the earth a long time ago. | 0:52:08 | 0:52:11 | |
In fact before Africa and Brazil | 0:52:11 | 0:52:12 | |
were separated by the Atlantic Ocean. | 0:52:12 | 0:52:15 | |
So you find them in both places but they're probably from the same | 0:52:15 | 0:52:17 | |
-asteroid. -Probably from the same | 0:52:17 | 0:52:19 | |
asteroid which broke up and then distributed | 0:52:19 | 0:52:21 | |
itself over those two continents. | 0:52:21 | 0:52:22 | |
I see. So this is billions of years old? | 0:52:22 | 0:52:25 | |
So billions of years old. Three, maybe four billion years old. | 0:52:25 | 0:52:28 | |
-Or three quarters of the age of the earth. -Oh, wow! | 0:52:28 | 0:52:31 | |
Gosh. So, our Sky at Night diamond, | 0:52:31 | 0:52:34 | |
we think was probably formed in a white dwarf, | 0:52:34 | 0:52:37 | |
landed on Earth billions of years ago and is now | 0:52:37 | 0:52:40 | |
sitting in front of us... | 0:52:40 | 0:52:42 | |
-Yes. -..for our celebrations. -That's exactly right, yes. | 0:52:42 | 0:52:45 | |
Well, that's pretty impressive if you ask me. | 0:52:45 | 0:52:46 | |
-Thank you so much for bringing them in. -Thank you. A pleasure. | 0:52:46 | 0:52:49 | |
Hi, Sky at Night. | 0:52:54 | 0:52:55 | |
Happy 60th from everyone | 0:52:55 | 0:52:57 | |
here at the European Space Agency | 0:52:57 | 0:52:59 | |
and from Rosetta. Nice one, keep up | 0:52:59 | 0:53:01 | |
the good work. | 0:53:01 | 0:53:03 | |
One of the other questions that has haunted astronomy, the proverbial | 0:53:05 | 0:53:08 | |
elephant in the universe is, are we alone? | 0:53:08 | 0:53:12 | |
Not just within our solar system but throughout the cosmos. | 0:53:12 | 0:53:15 | |
In 1957, | 0:53:15 | 0:53:16 | |
nobody knew if there were worlds orbiting other stars. | 0:53:16 | 0:53:19 | |
The first exoplanet wasn't detected | 0:53:20 | 0:53:22 | |
until 1995. | 0:53:22 | 0:53:24 | |
But now we know of over 3,000 planets orbiting distant stars. | 0:53:24 | 0:53:29 | |
In February this year, | 0:53:30 | 0:53:32 | |
the most exciting discovery yet was announced. | 0:53:32 | 0:53:34 | |
A whole system of potentially habitable earth-like planets. | 0:53:36 | 0:53:40 | |
Orbiting the cold dwarf star, TRAPPIST-1. | 0:53:40 | 0:53:43 | |
Chris has been talking to one of the lead scientists on the project, | 0:53:45 | 0:53:48 | |
Amaury Triaud, to find out more. | 0:53:48 | 0:53:50 | |
I think, one of the most significant | 0:53:52 | 0:53:53 | |
discoveries in the Sky at Night's 60 years is just last month | 0:53:53 | 0:53:56 | |
the announcement of planets around | 0:53:56 | 0:53:58 | |
a star called TRAPPIST-1. | 0:53:58 | 0:53:59 | |
Can you tell us what you were looking for and what you found? | 0:53:59 | 0:54:02 | |
What we found is around this small star, | 0:54:02 | 0:54:05 | |
we have seven planets all turning very close to the star. | 0:54:05 | 0:54:08 | |
The outermost planet is only 6% of the Earth's sun. | 0:54:08 | 0:54:12 | |
So all of those will be well within the orbit of Mercury? | 0:54:12 | 0:54:14 | |
-Completely. -So it's a very packed system. | 0:54:14 | 0:54:17 | |
What do we know about those planets? | 0:54:17 | 0:54:18 | |
All seven planets have sizes and | 0:54:18 | 0:54:21 | |
they are masses measured to be comparable | 0:54:21 | 0:54:24 | |
to the Earth. So they have compositions, | 0:54:24 | 0:54:26 | |
densities comparable to the Earth. | 0:54:26 | 0:54:29 | |
All seven are far enough from the star that we consider them to be | 0:54:29 | 0:54:32 | |
temperate, meaning that under certain | 0:54:32 | 0:54:34 | |
geological and atmospheric conditions, | 0:54:34 | 0:54:36 | |
water could be liquid if there is water there. | 0:54:36 | 0:54:38 | |
And that is why we are so excited | 0:54:38 | 0:54:40 | |
because this is the first system where | 0:54:40 | 0:54:42 | |
we can test whether liquid water can exist on the surface of a world | 0:54:42 | 0:54:46 | |
outside the solar system and then hunt for evidence of life. | 0:54:46 | 0:54:50 | |
A lot of the discussion after the discovery was immediately about the | 0:54:50 | 0:54:53 | |
star. This is a very different star. | 0:54:53 | 0:54:56 | |
Stars like TRAPPIST-1 form the majority of stars in our galaxy. | 0:54:56 | 0:54:59 | |
Most stars are smaller than the sun. | 0:54:59 | 0:55:01 | |
That's right. Just like TRAPPIST-1 and slightly bigger. | 0:55:01 | 0:55:04 | |
Most planets similar in size and mass to the Earth | 0:55:04 | 0:55:07 | |
mostly exist around such stars. | 0:55:07 | 0:55:09 | |
So looking at TRAPPIST-1 is looking at | 0:55:09 | 0:55:12 | |
the majority of earth-like planets in the universe. | 0:55:12 | 0:55:15 | |
But how will new facilities affect this? | 0:55:15 | 0:55:17 | |
I know people are excited about the James Webb Space Telescope, | 0:55:17 | 0:55:20 | |
for example. | 0:55:20 | 0:55:21 | |
The James Webb Space Telescope will be launched in late 2018. | 0:55:21 | 0:55:25 | |
It has the time to study each of the passages of the planet | 0:55:25 | 0:55:28 | |
in front of the star and so through those observations | 0:55:28 | 0:55:32 | |
we will note what type of atmosphere, what climate, | 0:55:32 | 0:55:36 | |
the level of greenhouse gases, | 0:55:36 | 0:55:38 | |
so we will infer the conditions on the surface | 0:55:38 | 0:55:41 | |
in terms of pressure and temperature. | 0:55:41 | 0:55:43 | |
Well, good luck and come back | 0:55:43 | 0:55:44 | |
-and tell us as the discovery goes on. -Thank you very much. | 0:55:44 | 0:55:48 | |
Well, that's how far we've come in the last 60 years but what about the | 0:56:07 | 0:56:10 | |
future? What will we be talking about in 60 years' time? | 0:56:10 | 0:56:14 | |
We've got our experts here. | 0:56:14 | 0:56:16 | |
Monica, what are you looking forward to? | 0:56:16 | 0:56:18 | |
Well, I'm looking forward to | 0:56:18 | 0:56:19 | |
understanding more about Mars because by six | 0:56:19 | 0:56:21 | |
years' time, we will have found fossilised life on Mars. | 0:56:21 | 0:56:26 | |
I really don't think I'm afraid that we'll find evidence of current life | 0:56:26 | 0:56:31 | |
on Mars but we will have found | 0:56:31 | 0:56:33 | |
evidence that there was life on Mars which | 0:56:33 | 0:56:35 | |
will link to life on Earth and this is, you know, | 0:56:35 | 0:56:39 | |
a really interesting question. | 0:56:39 | 0:56:41 | |
Michelle, what about the outer solar system? | 0:56:41 | 0:56:43 | |
I'm much more interested in the outer solar system, absolutely. | 0:56:43 | 0:56:46 | |
But we've got missions going to Europa. | 0:56:46 | 0:56:48 | |
Where else do you think we will have been? | 0:56:48 | 0:56:50 | |
Well, there's talk about going to | 0:56:50 | 0:56:52 | |
Uranus or Neptune because those are the gas giants | 0:56:52 | 0:56:54 | |
we know the least about in our solar system. | 0:56:54 | 0:56:57 | |
-We just had one flyby. -That's right, that's right. | 0:56:57 | 0:57:00 | |
But from my perspective, | 0:57:00 | 0:57:01 | |
our understanding of the icy moons of Jupiter and Saturn are making us | 0:57:01 | 0:57:05 | |
wonder about whether we might find liquid water outside of our | 0:57:05 | 0:57:10 | |
solar system around some of the exoplanets that have been found. | 0:57:10 | 0:57:13 | |
So let's have a prediction. | 0:57:13 | 0:57:15 | |
In 60 years' time, what's the hot topic in exoplanets? | 0:57:15 | 0:57:18 | |
I think the biggest hot topic is finding out how frequently life can | 0:57:18 | 0:57:21 | |
emerge. Not just is their life but how frequently can we find life in | 0:57:21 | 0:57:24 | |
-the universe? -So you are convinced we will find life out there and | 0:57:24 | 0:57:27 | |
then we'll just have many examples of it. | 0:57:27 | 0:57:29 | |
I think there will be a lot of claims. | 0:57:29 | 0:57:33 | |
The road is really hard but I do hope that before I pass away, | 0:57:33 | 0:57:37 | |
-we will know. -But do you think maybe an extraterrestrial intelligence | 0:57:37 | 0:57:43 | |
will have got in touch with us to put everything into perspective? | 0:57:43 | 0:57:46 | |
I've got my list of questions. | 0:57:46 | 0:57:48 | |
They might have the answers, you know? | 0:57:50 | 0:57:52 | |
It's just like you can speculate. | 0:57:52 | 0:57:54 | |
If they do, we'll definitely interview them on The Sky at Night. | 0:57:54 | 0:57:58 | |
That's all we've got time for this month but it's clear there's a lot | 0:57:58 | 0:58:01 | |
to look forward to and whatever happens and whatever is discovered, | 0:58:01 | 0:58:04 | |
we'll be here to report it for you. | 0:58:04 | 0:58:06 | |
We'll be back in June with a special from Rome. | 0:58:06 | 0:58:09 | |
In the meanwhile, enjoy the spring skies, | 0:58:09 | 0:58:11 | |
check out this month's Star Guide | 0:58:11 | 0:58:13 | |
-online and, of course, get outside and get looking up. -Goodnight. | 0:58:13 | 0:58:17 |