It may not have done anything for 9000 years, but now Chile’s Chaitén volcano has decided to start erupting it’s doing it big-time. Blowing ash 12 miles up into the sky, it has caused stunning ‘dirty storms’ where the huge dust clouds have turned into ferocious lightning storms. The photos are pretty breathtaking – although I must say I’m glad I don’t live anywhere what seems like a volcano taken out of the apocalypse.

It looks stunning, but just how do you get so much lightning at once? Basically, as the billions of ash and dust particles rub together in the sky, static electricity causes some of them to become charged – just like rubbing a balloon on your jumper can make it become statically charged.

These charged ash and dust particles can then trigger huge bolts of lightning, some reaching down to the ground and some staying between the clouds. The result: a dazzling show of light – and of course sound as well.

Chaitén’s not just making dirty storms – its ash clouds are spreading right over as far as the Atlantic Ocean, and it’s spewing lava out too (although not at a very high rate yet). It’s definitely something to keep an eye on over the next few days.

National Geographic’s done a great interactive detailing everything you could ever want to know about volcanoes – click here.

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.

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’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.

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.

Happy Earth Day everybody! If you want to be green but don’t have the time, or don’t know how to, today’s the day to start saving our planet. We’re always hearing about how our planet is in danger of being destroyed by humans – the picture many scientists paint for our amazing planet’s future is not pretty.

Get this – by the middle of this century, much of the Eastern Amazonian rainforest is projected to have turned into savanna because of water shortages and rising temperatures – think of all the biodiversity that will be lost as a direct result of us being too lazy to walk to work.

In another century’s time, the polar bear may be no more. We’ve only recently begun to realize how our poles are affected more than any other region of the planet, leaving not just polar bears but also seals, birds and penguins in danger of extinction because we’d rather spend money on a new flat-screen TV or a gas-guzzling monster truck.

It’s not just animals – as we’ve all seen with the global food crisis over the last few weeks people are already dying in their thousands because of climate change and pollution. That figure could rise to millions in just a few decades. It’s a sobering thought that we’re ‘murdering’ someone in Africa whenever we take a plane when we could take the train for a few dollars more.

BUT! Wait a minute – that all sounds rather depressing, doesn’t it.

The great thing is that each and every one of us has the ability to turn these dim predictions around – it’s amazing to think that we as individuals really do have the power to change the world. I’m not just saying that – it really is true.

If you tried to make your life a bit greener, then over the next decade you could have saved the lives of a family in Africa, a polar bear and its cub in the Arctic, an orangutan and its babies in Indonesia… and a whole load more.

Earth Day isn’t meant to be a day of pessimism as some people make it out to be – it’s one of the happiest days of the year, when we can smile as we think how wonderful, how mind-boggling it is that you, and me, and everyone else in the world, can save the most beautiful, stunning, and simply amazing place in the whole Universe.

Go on – today’s the day to change the world. Now you’ve finished reading this post, why not go out and do something amazing. You’re in good company – you’ll be part of a movement millions strong to change the world. It’s an exciting prospect, and it’s even more exciting that we can all be a part of it.

You really can do it!

p.s. While it’s Earth Day, why not try out a couple of quizes to see how green you are – tell everyone what you got by leaving a comment! Don’t be embarrassed. :)

Click here and here.

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 new 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!

How old can something living be? Humans aren’t too good, coming in at about 75 years in the developed world. Tortoises often live until they’re 150, but 150’s nothing compared to some trees. A few Bristlecone pines in California date back a massive 5000 years, but they may no longer be the oldest living thing in the world.

A new tree found in Sweden has been alive for a staggering 10,000 years according to scientists, meaning it started growing just after the end of the last Ice Age

 It doesn’t look like the most impressive of trees – OK , I have to admit it looks pretty pathetic since it’s supposed to have been growing for so long. (I thought maybe National Geographic had put the wrong picture up until I read the article. )

But this tree has a special trick: the trunk lasts for ‘only’ about half a century, and when the trunk dies a new shoot springs up from the roots. This means that what we actually see of the tree isn’t that old, but its roots have been radiocarbon-dated back thousands of years. (I hope I don’t get any comments from my older readers who wish they were a tree – the trees’ method of looking young is so much more effective than all these beauty creams.)

The good news is that this tree could mean our planet won’t suffer quite as much from climate change. Because it started growing so soon after the last Ice Age, it’s started scientists thinking that maybe trees can migrate faster than we thought, so maybe there won’t be as many dead trees because of global warming.

I always like good news – it’s great to hear that maybe our forests won’t die as soon as we thought they might. But that’s not an excuse for us to forget about the environment – after all, it simply means that the trees will take longer to die out.

And there’s some bad news for this little tree too unless we stop churning out extra carbon: it will soon be swamped by thousands of other trees that will migrate north because of our pollution, and it will probably die. Just think about that next time you get in your car.

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.

So 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.

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.

Back in the days of ancient Greece or Rome, if someone could magically generate lightning-on-demand they’d probably be hailed as a god. Until not too many years ago most people believed that lightning and the roaring thunder that follows were some sort of warning or punishment from the heavens.

Well now scientists in New Mexico have put an end to those theories – or at least they nearly have. By firing lasers into a thundercloud they just about managed to generate a bolt of lightning. They didn’t actually manage it because their techniques aren’t yet well enough developed, but they say they should be ready before too long.

It sounds pretty cool doesn’t it, lightning whenever and wherever you want it (although obviously it only works when you’ve got a thundercloud). So how did they do it? It sounds almost like science fiction: they shot laser beams up into thunderclouds, which caused a line of gas in the cloud to become ionized – that means it was given a charge.

Because lightning is essentially just a huge stream of charged particles, the line of particles that the laser created acted much like a lightning rod, and it directed the flash of lightning downward. It didn’t hit the ground in this experiment because the technique used was not powerful enough, but before long scientists should have mastered the technology.

It’s all very well being able to generate lightning, but as with so many experiments like this you just have to wonder, well, why? Actually, it could have some good uses. By knowing exactly when and where lightning is going to strike, scientists can do their research into this deadly killer a lot more easily. It’s also going to be useful for testing how lightning-resistant new planes and power lines are.

We’ve already discovered how to create rain (well at least sort-of), and now we can make lightning. It’ll be interesting to see where weather research takes us next in the decades ahead. I bet those scientists wish they lived in Ancient Rome – think of all the special treatment they’d get now as gods!

National Geographic has an excellent interactive page showing how lightning works.

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.

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.

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.

All frogs have lungs, right, because otherwise they couldn’t breathe. Well that’s what we used to think – until now. Scientists have discovered a frog that doesn’t need lungs – instead it breathes through its skin, like fish do.

But wait a minute… since frogs are amphibians and spend a lot of their lives in water, why would they have lungs anyway? In fact, all frogs can breathe through their skin, but most frogs also have lungs so that they can cope with being out of water for long periods of time. That’s what makes this new frog species so unique – it has got rid of its lungs and gone to gills-only, as if it was evolving back into a fish again.

Why would it want to do that? This particular frog lives in fast-flowing, cold waters (on the Indonesian island of Borneo). Fast cool water contains more oxygen than still warm water, so it can get more oxygen directly from the water than most frogs can.

Also, it has a lower metabolic rate than other frogs, meaning it doesn’t need as much oxygen anyway.

Borneo

However, scientists are still puzzled as to why the frog would want to get rid of its lungs entirely. After all, frogs’ noisy mating sounds require lungs, so surely any species that lost its lungs would not be a successful breeder – at least that’s what we used to think until this species was discovered.

Maybe the new species survived fine staying in water all the time, and having lungs was a waste of energy – we really don’t know. One theory is that the loss of lungs enabled the frog to become flatter, and get a bigger surface area. Bigger surface area means more space for air to enter through the skin.

Scientists hope to carry out much more research into this new species, although environmental factors like mining and climate change could make it extinct before we have a chance to discover all its secrets. And what a tragedy it would be to lose this intriguing creature before we even got to know it properly.