The conditions on Venus are hard to describe. Many planetary scientists say "Start by imagining Hell and work up from there." It's an environment where words like "over 500 degrees Celsius" get thrown around, and it's flat-out crushed every probe we've sent into it. Even worse, there's almost no water, and the European Space Agency have been finding out why.
Venus was created at about the same time as Earth, in about the same place, and it's roughly the same size - it would therefore have started with the same materials as us, drawn together from the same region of the planet forming dust left over from the sun. But Venus now has only 0.001% of our water content, and a couple of flybys by the dynamically named Venus Express may have revealed the reason.
Last year the probe discovered hydrogen and oxygen streaming off the night side of the planet in a 2:1 ratio, which you might recognise as the ratio in H20. If not, we're sure you can now deduce it. It seems that what little water Venus has left is being blasted apart in the atmosphere by the solar wind, a vast stream of charged particles blown out by the sun. Now, the Express has passed by the dayside and measured almost three hundred kilograms of hydrogen a day being lost into space. It hasn't found any oxygen yet, but the search continues.
Earth is defended from the atmosphere-flensing radiation by its magnetic field, and the data set indicating how vital that is may be short, but it's quite compelling. Earth, magnetic field, alive. Venus, none, dead. Mars, none, dead. We may want to hold on to this thing. Not that we have the tech to do anything about it should it stop or decide to flip or something. Luckily, it would never do such a thing.
Wait, it does do that? Oh. Well, good luck, us.
Bron: dailygalaxy
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