17/03/2014 Newsround

Evening all. Ricky here with your top stories.

First, to France, and residents and tourists in Paris would have noticed

a lot less traffic on the roads today. That's because only cars with

odd-numbered registrations have been allowed on the cities roads - all in

a bid to reduce the amount of smog, the build up of factory and car

emissions, in the city. But as Nel's been finding out, this isn't the

first time a major city has had to come up with a way to battle against

the smog. Paris looking at its best - the

Eiffel Tower in all its glory. Paris on a bad day - smog hanging over the

city. The smog in the French capital is mainly caused by fumes from cars

and factories, and has been made worse by unexpected warm weather and

cool nights in the city. Because smog can make it hard to breathe,

people in Paris decided to ban half the cars on its roads until things

improve. But it's not just in France where smog is a problem: Milan,

Italy - cars have been banned from streets when air pollution reaches a

certain level. Beijing, China - and some of the worst smog levels in the

world. In the past, half the cars were banned and factories closed,

but the smog hasn't gone away and dealing with it is back on the

government's to do list. And Los Angeles, America - In the 1950's the

smog was so bad that schools and factories were temporarily shut

down. The ban on cars in Paris is set to continue until the smog

clears, but, if it returns, drivers will need to get used to keeping

their cars at home. A strong earthquake has been felt

near Los Angeles in California today. The quake measured 4.4, and

struck shortly before 6.30am in the morning, local time. Authorities say

there have been no reports of damage or injuries, though. This local TV

station captured the moment the quake struck.

Wow! There's a big earthquake, right now. It's really strong. A strong

jolt, and it's still going. NASA's Messenger spacecraft has

discovered that Mercury has shrunk since it first formed.

NASA say the planet has reduced in size by four and a half miles from

its centre to the surface with one theory that Mercury may have formed

further out in the solar system before drifting towards the sun.

What do you get if you cross a giant swing with a bungee rope? This

amazing ride, of course, and its creators say it's the most insane

extreme rope-swing bungee ever! This swing was created by Mike Wilson and

Andrew Kirkpatrick who travelled to South Africa to build it. Users

plunge 600ft down, and riders experience a four second free-fall.

I would love to have a go on that. Amazing!

When you're online, later, don't forget to check out the Newsround

website to see more pictures of these purrrrfect pets from a feline

fair in South America. Leah's back in the morning.