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!

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.

Replica Solar System discovered 5,000 light years away

BBC News

Back in ancient times most people thought that our planet was at the center of the Universe. Then we thought it was the Sun, and not too long after we realized that we’re actually just a tiny part of one of billions of galaxies in a Universe filled with trillions of other stars. Just over a decade ago one of the last things that we thought might be unique about our Solar System was disproved – the first ever planet outside our Solar System (an ‘exoplanet’ for short) was discovered around another Sun.

Wikipedia Now our uniqueness has been eroded away a little bit more – a British team of astronomers has discovered what looks a bit like a replica of our own Solar System, orbiting around a star 5000 light-years away.

OK, it’s not an exact replica, but the resemblance is quite striking. Two giant gassy planets (like Jupiter and Saturn in our own Solar System) have the same mass ratio to their sun as Jupiter and Saturn have to our own Sun. And the size of their orbit is proportionally the same as the orbits of Jupiter and Saturn. (The star in the newly discovered system is only about half the size of our Sun, hence the reason why all the figures are given as ratios). The orbital period of the giants is about the same too.

So what about a copy of Earth and the other inner, rocky planets? Well, the scientists didn’t actually discover a new Earth, but they say that the existence of an Earth-like planet is quite likely because there is plenty of empty space in between the gas giants and the star.

Wikipedia Unfortunately there’s not much chance of us discovering any more planets in this system – at least not yet, anyway. Current techniques simply aren’t powerful enough to see such small objects so far away.

But wait a minute… if the system’s so far away, how could we detect that the giant gas planets were there? They’re pretty tiny too, surely, compared to the size of their sun?

They used a clever trick called ‘gravitational lensing’, which involves the effect first predicted by Einstein that if you put a heavy object (like a star) in front of another object (like another star further away), the star in front will bend the light from the star behind because gravity bends light. This enables us to see faraway objects much bigger than we would usually be able to see them. (Click here to read more about gravitational lensing, and how it enabled the Hubble Space Telescope to see a galaxy 13 billion light years away.)

Since we don’t know for definite that there’s a replica Earth in this system, should we really be getting so excited? I think the answer should definitely be yes – in the decade since we first discovered extrasolar planets, 300 planets outside our Solar System have been discovered. The more variation among these planets, the more chance of eventually finding ET. And that would be seriously cool.

Click here for NASA’s excellent exoplanet website: PlanetQuest.

The youngest planet ever discovered – only a few hundred years old

planeten.ch A few hundred years is a huge length of time for humans, but in cosmic terms it’s absolutely tiny. A hundred years in the world of Space could easily be compared to a millisecond for humans. But now scientists have discovered a planet that may have formed in as little as a few hundred years – which beats the former fastest forming planet by about 10 million years.

OK, it hasn’t finished growing yet, but the fact that it can be classified as a planet when it’s only been around for so little time is amazing astronomers all over the world. And the planet’s not the only interesting thing – its sun has only been around for a few hundred thousand years. (By the way, the planet and its sun are around 520 light years from Earth.)

So if this planet’s so young, how did astronomers find it? They used the Very Large Array (VLA) in Arizona to search for wavelengths of radiation that corresponded with pebble-sized lumps of rock (different sizes of rock emit different amounts of heat). They looked for pebbles because they are a vital hint that a planet is being formed.

National GeographicIt may be an intriguing discovery, but does is actually mean anything in terms of knowing more about our Universe? It certainly does – and it is stirring up quite a lot of controversy in the process. When stars form, they develop an area of rocks and gases around them, and these rocks and gases can eventually start to group together too form planets.

People used to think that planets formed when these rocks randomly collided, creating bodies with bigger and bigger gravitational attraction, which led to a sort of runaway growth. But this would take a very long time to produce a planet.

andrew.soave.net An alternative theory, backed by this latest discovery, is that planets actually form when an area of greater density within the area of rocks orbiting the star starts to contract, a process that could be complete within several thousand years.

OK, the difference between the two methods of planet formation don’t sound huge, but they have massive implications for scientists trying to understand the origins of our Earth. Let’s just hope that the meeting of the British Royal Astronomical Society (where this discovery was announced) won’t turn into a war between feuding scientists.