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Thursday, 7 June 2012

Venus (an extreme world) and Vesta (an extremely battered world):

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The transit of Venus was as spectacular as promised, although not from my house, as we've had our allocated five sunny days of summer here in Manchester What's up with that? [1]

However, other parts of the world were luckier, and spacecraft don't suffer from such things, so here are some truly amazing snaps from:

The NASA/JAXA Hinode [2] spacecraft....

Image above: The planet Venus begins its passage across the face of the Sun. Image courtesy of NASA/JAXA.

....the Arctic island of Spitsbergen....

Image above: The transit of Venus from the Arctic. Where the weather was, apparently, better for it than in England. Image courtesy of Michel Breitfellner and Miguel Perez Ayucar/ESAC.

 ....Canberra, Australia....

The Venus transit as seen from down-under. Please forgive this pom for calling it that, I realise it is in fact on the top of all the world. Don't make me play Australian rules football, please. I wouldn't survive. Image courtesy of Michel Breitfellner and Miguel Perez Ayucar/ESAC

As well as videos from ESA's Proba 2 micro-satellite [3]...

Video above:  The transit of Venus, as seen from the ESA Proba 2 spacecraft. The wobble is due to the satellite wobbling, not Venus. Venus does enough strange stuff already. Video courtesy of ESA.

...and NASA's Solar Dynamics Observatory [4].

Video above: The transit of Venus, as seen from the Solar Dynamics Observatory spacecraft. The roiling plasma on the surface of the Sun is complex and beautiful enough for me to watch by itself. And then it's got Venus in there to! Courtesy of NASA/JPL.

Image left: NASA has built the Extreme Environment Chamber. It's a beast, like a pressure cooker designed to dissolve, incinerate and pulverise the food in a split second. They plan to build machines that can live in it for a week. Image courtesy of NASA/Glenn.

In other Venus related news: NASA's Glenn research centre have built an Extreme Environment Chamber [5], to recreate the brutal conditions of the Venusian surface. The chamber is much too serious a machine for me to do something silly, like call it an Xtreme Environment Chamber.
Ooops. Anyway, each bolt to hold the lid in place weighs 45 kg, or as much as a... well I can't think of anything that weighs exactly that much. But that's a lot for one bolt. The engineering has to be that hardcore: Having a simulated Venus inside makes the chamber a huge explosion, waiting to happen.

The main purpose of all this is to work out how to build electronics, machinery, and sensors, that will operate under the crushing  Venusian pressure and heat [6]. Initially the aim is to build something that would last for five days there. For example: The Glenn team are developing a seismometer that would provide insights into Venus' extreme geological processes [7]. Others are working on measuring how sound, light, and the Venusian soil would behave under those conditions.

The applications for the chamber go beyond testing for Venus. According to Rodger Dyson, the principle investigator for the project, if you can work on the surface of Venus you can work anywhere in the solar system - except the depths of the atmosphere of Jupiter, which has all of Venus' charm with massive radiation levels added on top.

Geoffry Landis, who works as an aerospace engineer at Glenn, has been involved in several proposed robotic missions to Venus [8]: "Venus is the planet that is closest to the Earth, both in distance and in composition," Landis has said. "It's very much Earth's twin, but in some ways it's Earth's evil twin."

Elsewhere in the solar system:

The Dawn [9] team have published a 3D map of Vesta [10], in both real and enhanced colour, to bring out the differences in the composition of its surface areas.

Video above: A 3D map of Vesta, made using the thousands of hours of data the Dawn spacecraft has collected. Video courtesy of NASA/JPL.

Two things about this make me swoon with space nerdyness: You can see how nearly spherical Vesta is, how it might well have been planet shaped in the past. And we can see how hugely varied the surface composition is, showing just how complex and tumultuous Vestan geological history was. For example: Iron abundance is shown in green in this image, and we can see how iron has been bought to the surface, in patches, inside the huge gap where the south pole of this protoplanet used to be.

Image right: The best guess we have to date on he internal structure of Ceres, based on its mass, signs of materials that have interacted with water on is surface, how warm we think it might have gotten, and computer models. It's not been ruled out that there might be a tiny hint of geological activity, and perhaps a little liquid water, deep down near its core. Image courtesy of NASA.

Dawn is currently moving from its low altitude mapping orbit to its final science orbit, averaging 420 km above the Vestan surface. Then, in August, Dawn will break orbit of Vesta and head out to it's next target: The enigmatic and (probably) ice laden dwarf planet Ceres [11]. The ion drive powered spacecraft will reach the king of the asteroid belt in Febuary 2015, spending longer at Vesta than planned because the mission has so far gone almost flawlessly. As it departs Dawn will still be taking images and readings of Vesta, particularly its north pole, which has been in winter darkness for much of its visit so far.
Image above: The Hubble Space Telescopes best shot of Ceres. Can't think of a good comparison for it, but it looks tantalising. Image courtesy of NASA/JPL.

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