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!

What’s bad about melting ice sheets?

New York Times Imagine a huge slab of ice with an area of about 200 square miles – if it was ever to melt it would release torrents of water into the oceans. The problem is that it already is melting – scientists with the British Antarctic Survey discovered last week that an iceberg that big has just broken away from a major Antarctic ice sheet. Now that the ice has been separated from the ice sheet, it will quickly disintegrate, and before long it will all have melted.

CNN OK, so this iceberg might raise sea levels a fractional amount. But does it really mean anything in terms of the big picture? Or did the media just hype up the story to bring in some more page hits and viewers? Although this event alone is not going to be devastating for our planet, the fact that it happened raises a whole load of worrying issues.

For a start, it’s clear evidence that Antarctica is warming faster than pretty much anywhere else on our planet. Aside from melting ice, why does that matter? Well, it certainly does matter – already, the population of krill (tiny shrimp-like creatures) has been dropping quite substantially because of the warmer waters. Krill is the primary food of loads of other marine organisms, so kill the krill and you’re also killing a multitude of species of fish.

CNN Another effect that’s fascinating is that the warmer Antarctica gets, the more it snows, and that snow decreases the chance of penguin eggs hatching successfully. What? Rising temperatures increase snowfall? I know it sounds weird, but it’s true – warmer temperatures give the air a higher humidity, causing more snow to fall.

Carbon Dioxide, the gas the virtually all scientists believe is causing global warming, is also having a direct effect on animals, not just by increasing the temperatures. Water is really good at absorbing that dreaded greenhouse gas, but this has the unfortunate consequence of turning the water more acidic. That then means that organisms with shells get their shells weakened by the acid, as well as suffering loads of other knock-on effects. (Read more about the effects of acidic waters in my previous post – aptly named ‘Climate Change won’t just kill Polar Bears’)

You might think that this post was a bit depressing – but that’s not how I want you to feel. Hopefully it’ll inspire you to do something, and make you realize that you yourself can play a big part in stopping climate change going too far. I know we are capable of doing it, but can we be bothered? Can you be bothered? Go on, give it a try. 🙂

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!

Shuttle Endeavour touches down safely in darkness

 NASA / National Geographic

It blasted off in darkness two weeks ago and has now touched down again at Cape Canaveral in the middle of the night. But Space Shuttle Endeavour’s mission was certainly nothing to be dark and depressed about – it successfully installed a huge robotic arm form Canada to the ISS, as well as delivering the first part of the huge Japanese space lab Kibo. (Click here for more on what Endeavour has been doing these past two weeks)

The great news is that we only have another couple of months or so until the next Shuttle launch – Discovery is scheduled to launch in late May. Its fuel tank was taken to the Kennedy Space Center Wednesday.

Is it really worth all these missions to build the ISS? The ISS is now 70% complete, and it certainly is not useless. Loads of important scientific research is being carried out as you’re reading this, and it has also been a vital exercise in seeing whether different countries can collaborate to create something so technologically advanced.

Here’s the video of the touchdown:

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.

Discovered on Mars: Salt that could pinpoint location of life

NASA / Wikipedia Whenever I’m putting salt on my food I don’t usually start me thinking about life on Mars. To be honest, I’d be a bit worried if anyone started thinking about extraterrestrial life instead of enjoying their nice meal (especially if it was while having a romantic dinner out).

 Hmm… what’s this got to do with science? A NASA probe (Mars Odyssey) has just discovered an area of salt deposits on the Red Planet. Although NASA / Wikipediasalt isn’t usually something you’d associate with life, it is in fact a huge clue as to where ancient Martian life may once have lived.

It’s all down to the fact that whenever water flows over rocks, it erodes them, absorbing some of the minerals contained in the rocks. Among these minerals is sodium chloride – or common salt – and its discovery on Mars could be pivotal in deciding where we go next to look for life on Mars.

In all the places where there are salt deposits we can be pretty sure that water once flowed there. Add to water the warmer temperatures that Mars had when the newly discovered salt deposits were found (they formed 3.5 to 3.9 billion years ago) and you get conditions quite favorable to life. Whether life actually existed or not remains to be seen, but knowing where liquid water once flowed makes the task of searching for life much easier.

CNN / NASAWhile I’m writing about Mars, here’s some disturbing news: NASA has just announced it is cutting funding to the amazing Spirit and Opportunity probes by 20%. As you can see by clicking here and here, these two rovers have been among the best ever sent to Mars, so it’s worrying that NASA isn’t willing to pay enough for them. It’s a shame that George Bush doesn’t realize that when he says he wants a man on Mars by 2030, he doesn’t realize that it won’t be free.

Check out the biggest volcano in the Solar System (on Mars) in 3D here, and read about the water-formed gullies recently discovered on the Red Planet here.

Oceans discovered on Saturn’s moon Titan

NASA As if it’s not already cool enough with its methane lakes, Grand Canyon-like geological features and status as the only moon in the Solar System with a thick atmosphere, Saturn’s moon Titan may now have yet another thing to show off about: NASA thinks that lying underneath its surface is a huge ocean of water and methane.

OK, it may be 63 miles below the surface, but the possibility of an ocean on Titan really is exciting, especially as it is thought to contain H2O – water. As we all know, water equals life and although Titan probably isn’t home to ET, the fact that another body in our Solar System has liquid water brings us increasingly closer to discovering life outside Earth.

ESA / NASA / Wikipedia But wait a minute… if the ocean is underground, and above the ground there is a dense, opaque atmosphere, how can we tell that there is an underground ocean? After all, as it’s 63 miles below ground you could hardly drill down into it.

Basically, it all began when a strange discovery started puzzling scientists: they were using radar on the Cassini probe to track the locations of various landmarks on Titan’s surface, but they found that the landmarks were moving between each flyby of Cassini. It could have been down to winds, but they would have had to be incredibly strong since some of the landmarks moved an amazing 20 miles.

The only plausible theory seems to be that the whole surface of Titan is floating on one massive ocean, and as currents in the ocean move the overlying land along, the landmarks move.

Wikipedia I’ve said many times before how amazing the Cassini mission to Saturn and its moons has been – take the recent flyby through the icy geysers of Saturn’s moon Enceladus for example. The great news is that NASA has decided to extend Cassini’s mission beyond its original scheduled finish this summer, meaning we’ll be discovering a whole load more weird and wonderful things about the ringed planet and its companions in the years to come. Go Cassini!

Click here for an excellent Titan interactive from NASA

Here’s an interesting post on CNN’s Sci-Tech blog.