Saturn’s lightning 10,000 times more powerful than Earth’s

NASA / MSNBC

I love being in the middle of a thunderstorm – being in the center of the light, noise and heavy rain is a really exhilarating experience. But new research from NASA’s Cassini probe makes me think that maybe Saturn would be an even better place to experience a massive storm.

Why? Saturn’s storms not only have thunderbolts thousands of times more powerful than Earth’s measly zaps of electricity, but the storms can also last for months on end. The current storm being observed by Cassini has been going on for over five months now – a record for the ringed planet.

Wikipedia Saturn’s huge size obviously explains why thunderstorms are so much bigger there than on Earth, but is that the only reason? Saturn, Jupiter and the other gassy planets are actually always bound to have more huge storms like this, because unlike our planet, their atmosphere is the planet, not just a thin layer on top of loads of rock.

Cassini’s discovered some other cool things about Saturn too – a 2000-mile wide storm near the South Pole that looked like a hurricane was discovered back in 2006, and of course Saturn’s many moons are proving to even more interesting than the giant planet itself.

That’s why it’s great news that NASA recently announced that funding for Cassini will continue until at least 2010 – hopefully even longer. Go Cassini!

Advertisements

Where is the brightest place on Earth?

Where’s the brightest place on Earth – the place that is illuminated most when the Sun has gone down? New York’s Times Square perhaps… what about the glow of office lights around London’s business district… or maybe the bustling heart of Mumbai, the world’s most populated city. They’re all pretty bright, but of course nothing could beat the flashing, colorful sea of lights that make up Las Vegas – the brightest place on Earth.

NASA has just released some new images of our planet at night, and I think it’s really fascinating to see what they tell us about our civilization.

Until not long ago, most of Saudi Arabia was a vast desert, void of human habitation. But now its cities are bustling, and as their population increases, so does its brightness. I love the little strip of light connecting Jeddah and Mecca in the photo on the right – that’s the tiny but well-illuminated road linking the two cities.

Earth It’s also really interesting comparing cities by day and night. The photo on the left is Chicago – as soon as darkness comes the gray and brown sea of buildings is turned into a mass of light, coming from every building, road and shop.

So how did NASA get these photos? It’s not as easy as you’d think – you have to bear in mind that the ISS (where these photos were snapped from) moves about 7 miles a second above Earth, and combined with the long exposure times necessary for such a dark photo, it’s difficult to avoid getting blurry photos, as any photographer will know.

The solution was to create a camera mount that rotated really slowly, to compensate the movement of the ISS. The result: beautiful pictures showing the amazing things humanity is capable of.

The only problem is that sometimes our lights go too far – many city-dwellers can’t see more than a handful of stars because artificial lighting lights up the sky so much. I’d really recommend looking at the International Dark-Sky Association‘s website – they’ve got loads of tips about how to reduce light pollution. But before that, just appreciate how fascinating our planet looks when it’s dark.

NASA’s new image of the stars that shouldn’t exist

National Geographic / NASA

Beautiful, isn’t it? But I think it also looks a bit weird compared to most galaxies. Lots of scientists think it’s strange too, although not just because of what it looks like.

Until now it was thought that the majority of stars always form in the centers of galaxies, because that’s where most of the star-forming material is. Also, there are lots of triggers for star formation in the center of a galaxy, like shock waves that come after stars explode and die that can trigger material to start reacting, and thus form new stars.

But as often happens in science, this new photo shows that maybe scientists were wrong about where stars form after all. The The Sombrero Galaxynew photo shows a huge number newborn stars in the outer red spiral arms of the galaxy – something unexpected, because the spiral arms are quite sparse compared to the galactic center 140,000 light years away.

We have known for a long time that stars can form in the spiral arms of a galaxy, but to find so many young stars in such a relatively empty empty area of space is puzzling astronomers. This new galaxy could revolutionize our understanding about how and where stars form.

It’s just one of those things about science – whenever you think you understand something, something crops up that means you have to start over. But hey, that’s how we make progress!

NASA’s twins that could save our world

Wikipedia Imagine a billion tonnes of scorching hot gas and radiation being hurled toward you – it’s not the sort of thing you come across every day.

This is actually something our Sun does on a regular basis, although fortunately for us our atmosphere stops anything too dangerous getting in and hurting us.

But satellites, as well as any astronauts in space, feel the full force of a Coronal Mass Ejection (CME) – as these massive bursts from the Sun are known – and they can be really dangerous.

That’s why NASA decided to launch the Stereo mission, two twin satellites that give us unprecedented views of CME’s – something that would be vital if a CME was ever to come toward us. (Click here for two interesting videos from Stereo)

And it’s not just about damage prevention – we’re learning loads about the Sun too like new footage from Stereo showing just how powerful solar bursts can be as they rip the tail off a comet. The Stereo probes are telling us loads of things we didn’t know about our parent star.

BBC NewsSo why are there two probes in Stereo – wouldn’t just one have been cheaper? The whole point of Stereo is to give us a 3D view of the Sun – just like having two eyes a small distance apart helps our brains give depth to our vision, the two Stereo probes can give us a three-dimensional view of our Sun because one follows a path slightly in front of Earth’s orbit, and its twin trails on behind.

What would happen if one of these CME’s flew straight into our planet? Something not many people realize is that the effects on our lives could actually be huge. For a start many satellites would be knocked out, meaning no television, GPS, weather forecasting and more for a few days. And then there’s cell phones, the internet, and anything else that needs satellites to work.

Wikipedia The good news is that thanks to Stereo, we will be given a few hours’ warning if a CME is heading toward our planet, giving operators vital time to shut down any satellites in the path of the Solar blast, as well as making sure any astronauts are safely inside radiation-proof areas.

The wonderful Stereo probes are yet another example of why scientific research isn’t just about proving some professor’s theory or doing some irrelevant calculations – it really could save our lives. Of course, until the day when a CME is headed our way, it’s always fascinating  to discover more about our amazing Universe.

Interested? Read about how radiation could prevent humans from ever going to Mars.

NASA captures a new 3D view of Mars’s moon Phobos

NASA You’d think that Mars’s moon Phobos – a 13.5-mile wide lump of brownish rock full of craters – wouldn’t be the most interesting place in the Solar System to take photos. But then space exploration does tend to throw up a lot of surprises.

One of NASA’s Mars probes recently captured the above image, and it’s revealing some fascinating details about something most people probably didn’t even know existed.

The most obvious thing about Phobos is the huge crater on the bottom-right of the image. Scientists say that its slight bluish color means it hasn’t been exposed to space as long as the rest of the moon, meaning the impact that produced the crater could have been quite recent.

Wikipedia Phobos may also be home to water-ice and materials rich in carbon, which is why a Russian-Chinese mission to collect samples from Phobos is expected to launch next summer.

NASA’s Mars Reconnaissance Orbiter snapped the new shot of Phobos from 4000 miles away, so I’m pretty impressed that the detail’s so good. In the full size image each pixel represents 22 feet (6.8 meters), so you can zoom in quite a lot. (Click here to download the full-size image. Be warned! It’s a 20mb file, so if you’re still using ancient dial-up be prepared to wait a few hours.) It’s really cool zooming in on the thousands of craters dotting the moon, especially the ones on the edge of the Moon and on the day-night border.

Phobos and Deimos What else is so great about the new image? OK, several probes have imaged Phobos before, but because MRO took two photos you can actually see the photo in 3D if you’ve got some of those special glasses.

The image also shows landslides around the massive crater (Stickney crater), and you can see some craters in the dark region illuminated by Mars-shine. This is when light from the Sun reflects off Mars onto Phobos, and it happens with the Earth and our Moon too – take a look next time there’s a crescent Moon.

Above all, I just think it’s amazing that yet another bit our Universe is proving to be so interesting. Before I heard about this photo I just though Phobos was a boring old lump of rock, but as you can see it’s actually a pretty interesting corner of our Solar System after all.

Want to know more about the Red Planet? See the Solar System’s biggest volcano in 3D, see photos of the first ever avalanche captured on Mars, and read why radiation may prevent humans from ever visiting it.

Radiation may prevent humans ever going to Mars

MSNBC / NASA

It’s amazing that the human race is now close to sending a person to another planet for the first time in the history of civilization – NASA hopes to put a man on Mars by 2030, or at least not too long after. But why will it take 20 years? Well, there are loads of problems scientists have to overcome like the psychological impacts of a 2-3 year Wikipedia / NASA trip, the problem of having enough food and water, and finding a fuel that would be powerful enough to power a heavy craft to Mars.

But there’s something perhaps even more important that people often overlook, and it’s something that could affect long-term missions to the Moon too – radiation from the Sun. It’s proving to be a huge stumbling block.

Our Sun constantly bombards our planet – and everywhere else in the Solar System – with a stream of assorted particles, many of which would be harmful to humans if we were exposed to them. In fact, these ‘cosmic rays’, as they’re sometimes also known, were the main thing that prevented life on Earth originating until a billion or so years after its creation. Only when a few resistant bacteria (and lots Wikipedia / NASA of volcanoes) started producing gases to produce an atmosphere could more advanced life develop.

Any mission to space obviously involves going outside our atmosphere, which means leaving the shield that protects us from solar radiation. Even with complex spacesuits, modern astronauts frequently see white flashes of light as solar particles interact with their eyes.

But if astronauts can cope with solar radiation now (for example on Shuttle missions and at the ISS), why wouldn’t they be able to cope on a Moon base or on Mars?

The problem is that unlike on the Shuttle or ISS, astronauts walking around on the Moon or Mars would have only their spacesuits to protect them. On a Moon base the astronauts would be exposed to radiation for days until they finished building the base, Wikipedia / NASA and on Mars the astronauts would want to spend several weeks exploring to make the 2-3 year journey worthwhile. All that radiation would build up, and could trigger things like cancer and tumors.

What’s the solution? It’s basically just a matter of trying to research better and better lightweight protection that can be used for spacesuits – but that could take many years yet. Let’s just hope it doesn’t take too long.

Check out my last post to find out what happens when solar radiation collides with our atmosphere: aurora. There’s a cool image of aurora from space.

Astronauts snap photo of aurora from space

Unfortunately I’m not lucky enough to have seen the spectacular light display visible every winter  – the aurora. At least not yet. But astronauts onboard the Space Shuttle Endeavour got to see the aurora from a very different perspective before they touched down – they saw the mysterious green light show from above.

So what is the weird green light in auroras? Basically, our Sun constantly bombards our planet with a multitude of particles (the solar wind), some of which interact with Wikipedia our atmosphere, causing gases in the atmosphere to glow. It happens mainly toward the poles in winter because these are the places where the solar wind impacts our planet most.

Green coloring comes from ionized oxygen – there is also a small amount of red/purple/blue from nitrogen.

Post a comment if you’ve had any aurora experiences!