The volcano hurling ash 12 miles high

National Geographic

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.

National Geographic 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.

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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.

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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 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.

Planet Earth plunges into darkness for an hour

MSNBC

Whoa! What happened to Sydney in the photo above? Was there a major power outage or something?

Fortunately no – although what actually happened was something even more important than a power outage. At 8PM local time on March 29, Sydney was one of the first cities to participate in ‘Earth Hour’, in which households, towns and even major cities around the world turned off their lights for an hour to try to help save our planet. And as you can see from the photos, the effect was quite impressive.

NASA Earth Hour started last year as a Sydney-only event, but this year it’s spread to the whole world thanks to WWF funding. By the time you read this, chances are that it will be past 8PM in the U.S., where buildings from the CNN Center in Atlanta to the Golden Gate Bridge in San Francisco will be thrown into darkness.

It’s all very well doing publicity stunts like Earth Hour, but do they really make a difference? Skeptics would say they’re just a gimmick – people are more bothered about the excitement of a candlelit dinner than about the real message of Earth Hour.

NASA But I really do think it will make people think. In some cities office workers were forced to turn their lights off on Friday evening so that they didn’t have to go in again on Saturday – maybe next week they’ll remember to do it again. And of course any publicity about saving the environment is always a good thing.

Oh yeah, and there’s one other huge advantage of having lights out for an hour – as you can see from the Sydney photo, the normally orange, light-polluted sky turned black during Earth Hour, making it one of the only times Sydney residents can ever see the stars above their heads.

Let’s just hope that Earth Hour can become an annual tradition all around the world. Put March 29 in your 2009 diary!

Hawaii’s volcano Kilauea starts exploding and erupting new lava

National Geographic It’s been erupting for 25 years now, but that doesn’t stop Hawaii’s volcano Kilauea throwing up new surprises. One of its major craters has now started exploding and oozing lava – the explosions are the first in 84 years, and the lava the first in a quarter of a century from this particular crater.

The explosion in the Halemaumau crater spread debris over an amazing 75 acres – I expect local residents got quite a shock. But what caused the explosion? Basically, it was because gas under increasing pressure below the surface finally had to get out somehow, and it did that by exploding through the rock. The lava came out for a similar reason – the pressure under the surface was just getting too great.

Since Kilauea’s been erupting non-stop for 25 years, should we really be making such a fuss over these latest events? Normally I’d say no, but it is interesting that these events follow other reported increasing activity by Kilauea (I wrote about it a few weeks ago). CNN / APIs Hawaii’s most famous volcano about to turn nasty?

As with all geological events (volcanoes, earthquakes, tsunamis, etc.) the simple and true answer is that we just don’t know. But I’ll definitely be keeping more of an eye on Kilauea now – it could definitely get interesting any day now.

Click here for more information on Kilauea, one of the world’s most fascinating volcanoes.

Mega-tsunami imminent in the Mediterranean – 100 years and counting

The 2004 Indian Ocean tsunami, which killed over 200,000 people | Image: Wikipedia It’s not every day that you have the same experience as the people who lived on the Mediterranean island of Crete in AD 365: All of a sudden, the ground below them rose a massive 30 feet (10 meters) in a burst of tectonic activity. Even with all our knowledge how the planet works, I’d still be pretty confused if that happened to me tomorrow.

But the huge uplift wasn’t all that happened: a massive tsunami was unleashed that went on to kill tens of thousands of people across the region, as well as destroying the ancient Egyptian city of Alexandria. It ravaged huge areas from Greece down to Libya, and managed to carry ships up to two miles inland.

Map of the Mediterranean island of Crete

Scary? It almost sounds like a Greek myth. But the worrying thing is that new research suggests that a similar tsunami occurs every 800 years – after the 365 tsunami, another one took place in around 1300, meaning that the Mediterranean is due for another wave of destruction anytime in the next century.

Millions of people live around the area that would be affected, meaning that if a tsunami was to strike it would cause unimaginable devastation. It could well be worse than the tragic 2004 south-east Asian tsunami that killed over 200,000 people.

But wait a minute… how can scientists tell that Crete rose 30 feet in AD 365, and that another tsunami is due soon? They know about Crete because there is a line of animal and plant remains running along Crete at a height of around 30 feet, like the line in a bath where water has been up to. And they know another tsunami is imminent because they have carefully analyzed the miniscule movements of the tectonic plates over recent years, as well as looking back at records of the 365 tsunami.

Should we be worried, or is this just a scare story? Some scientists argue that the 365 tsunami was just a one-off event… I’m personally more convinced by the 800 year cycle story – you’ll have to decide for yourself.

Related: Did you know that Italy is currently on a collision course with Croatia – click here

Kilauea: The world’s most active volcano opens up a new lava path

Wikipedia As it’s been erupting continuously for the last 25 years and is the world’s most active volcano, it’s no real surprise that the Hawaiian volcano Kilauea has now started spewing out even more lava. Destroying three abandoned homes in the process, the lava has recently started following a new path along Hawaii’s Big Island, although scientists say there’s nothing to worry about. (Click here for a video)

In fact, although Kilauea has erupted 34 times since 1954, as well as the current 25-year-old eruption, it is not really a dangerous volcano at all.

Instead of building up huge reserves of magma and then letting it all go suddenly, like Italy’s Mount Vesuvius for example, Kilauea just lets a gentle stream of lava flow pretty much continuously. It is so slow in most places that you could outpace it simply by walking, meaning it poses very little danger.

Wikipedia However, it does sometimes have impressive jets of lava (up to 1000 feet tall) that earned it the nickname the ‘drive-by volcano’, because you could ride by and be amazed by the fountains.

The latest twist in Kilauea’s lava path doesn’t really pose any danger – residents had plenty of warning that their homes would soon be destroyed, giving them enough time to set up a home in a safer location.

I’ve not been lucky enough to go to Kilauea – yet. Leave a comment if you’ve been!

 UPDATE: Kilauea has now started exploding for the first time in 84 years, and more new lava is erupting. Click here for the exciting details.

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