The spacecraft MESSENGER had revealed some interesting stuff from Mercury. After mapping the surface of the only inner planet not previously fully mapped, it has been revealed 40% of that surface is smooth, probably due to volcanic flows. A large impact basin nearly 4 billion years old has also been uncovered, but the most interesting stuff is in Mercury’s atmosphere.
Yes, I mentioned atmosphere, even these distant rocks we commonly refer to as airless still have some kind of atmosphere. Mercury produces much of its through sputtering, where solar wind particles strike the surface and knock the odd atom or two out. Magnesium has been detected in the exosphere of Mercury suggesting it has it on its surface. There was also a dramatic difference between the atmospheric composition measured now and during the last fly past, thought to be due to changes in the magnetosphere of Mercury – the region of space controlled by Mercury’s magnetic field. Changes in the magnetosphere would be reflected in changes in the amount of particles sputtering the surface, which then alters the atmospheric composition. All fits together nicely now, doesn’t it…
via American Friends of Tel Aviv.
The study of the composition of our atmosphere shows that it has been altered over its many years of existance. Lighter materials have leaked from the top. Meteors have dropped in from time to time and cosmic rays have bombarded. Now a study of Comets has suggested a few of those also mixed with the rest of our planet’s reservoir of material to help with the formation of life. It is known some of the building blocks of life can be found on comets, but it has been difficult to show that they then came here. Now Professor Akiva Bar-Nun of the Department of Geophysics and Planetary Sciences at Tel Aviv university believes he has found a way. Noble gases are inert gases that simply sit around doing very little in terms of reacting with other gases. They are delivered and they wait. Studying the proportion of Noble gases and comparing them to the solar proportions shows they differ from whatever formed the Sun. Comparing again to meteors and we see they differ still – more of some than others are required to land on Earth. This short fall is, according to Bar-Nun, to be made up from Noble gases in comets. If this is true then an idea of how much material has been dumped here by our icy friends from the very edge of the solar system can be gained. From that, we can determine how many of the building blocks of life were around when first Earth built that life.
You may think in space there’s no more air to suck out of the room, nevertheless, a series of talks on Space Law during a conference at the University of Nebraska-Lincoln, has turned the eyes of the legal profession to the skies. From the liabilities of inaction on the threat of asteroid collisions to the potential ramifications of satellite killer technology, it seems national and international law can be brought to bear on anything… As if to preempt any jokes, the title of the conference is “Near-Earth Objects: Risks, Responses and Opportunities – Legal Aspects”
via Universe Today.
A relatively young crater has been sighted by the Mars rover Opportunity. The crater still has relatively sharp edges, unlike its older compatriots, all of whom have been eroded over time to soft undulations. Finding and analysing relatively young craters (a sprightly 100,000 years, as opposed to roughly 3 million for the fogeys around it) allows a chance to see how fast the winds actually do their eroding, which in turn gives an indication of climatic changes over the length of time of the young crater, especially when compared to other young craters.
In other news, Spirit, the other Mars rover, is perking up a bit having had its solar panels cleaned by the wind. Power generation is now above the dead level.
I enjoy sticking my astronomy photos on flickr (see sidebar on the right), but sadly feel I will never produce the range or quality of image currently available on Nasa’s new website of all its images, imaginatively titled NASAImages.com…
As part of the International Year of Astronomy, 2009 and Hilo’s annual astroday, a pack of astronomy related cards has been produced. These show the thirteen telescopes up on Mauna Kea (soon to be twelve if the reports on that telescope on card nine is anything to do with anything), several solar system and extra solar objects that are studied there. The physical packs will be handed out on the astro day in Hilo, but if you can’t make it there by May the second, then there’s always the chance to go to the website and download them for yourself. One condition though – no selling!
via Hawaii Tribune Herald.
Due to a cut in funding, Caltech will be unable to continue running the 10.4 metre Caltech Submillimetre Observatory. The CSO has been running since 1988, observing long wavelength infrared light, or short wavelength radio waves and still produces excellent science. However, Caltech is expected to announce that interest has shifted to other facilities and so will be disposing of the Observatory. It is not yet known whether the license for having the observatory on Mauna Kea actually allows for decommissioning, but that is all expected to be resolved before an announcement on Thursday.