NASA has announced the discovery of microbes that can replace phosphorus with arsenic, which is toxic to all other known life forms. It can substitute arsenic for phosphorus in the (normally phosphoric) backbone of its DNA and RNA, in its cell membrane, and even in its ATP (adenosine triphosphate), which is a central energy-carrying molecule in all cells.
NASA’s release: http://www.nasa.gov/home/hqnews/2010/dec/HQ_10-320_Toxic_Life.html
So, how do you think this will affect the search for life elsewhere? It might not be life on Titan (as some speculated the news release might be about), but it’s still pretty cool.
Forum topic for convenience: http://forums.leagueofreason.org.uk/viewtopic.php?f=8&t=6453
This truly spectacular image (click for full size) shows us the silhouette of STS-125 Space Shuttle Atlantis against the Sun. Taken for NASA by Thierry Legault on Tuesday, it captures Atlantis en route to its rendezvous with the Hubble Space Telescope (HST-SM4). Hubble is currently in the shuttle’s cargo bay, where the crew yesterday installed the Wide Field Camera 3 (successor to the Wide Field and Planetary Camera 2). On saturday, they will also install the Cosmic Origins Spectrograph and repair the Advanced Camera for Surveys. They are also making several other repairs, in what will be the final Hubble servicing mission before its orbit is terminated, probably around 2014. Atlantis is just under 40 metres long, and 350 miles high in this picture!
Anyway, I thought some of you might enjoy this beautiful image too.
Yesterday, NASA’s Kepler spacecraft began its 3 and a half year mission to hunt for planets among over 100,000 stars. It has been in an Earth-trailing heliocentric orbit for over 2 months since its flawless launch from Cape Canaveral aboard a Delta II rocket, and now that it has finished commissioning and has been focussed optimally, it is ready to start… staring.
Kepler will stare continuously at a single patch of sky throughout its mission. This is known as a fixed field of view. By looking at exactly the same stars with great sensitivity, the Kepler science team hope to measure very slight periodic dips in their apparent brightness. This will signal the transit of an orbiting planet from our perspective. The Kepler mission will achieve an unprecedented level of precision, by using a collection of techniques known as differential ensemble photometry. Variations in seeing and extinction are accounted for, and shot noise is dealt with onboard the spacecraft.
So high is Kepler’s sensitivity, that it will be able to detect transits from planets comparable in size to Earth orbiting in the habitable zones of their stars. Of course, the mission was designed this way from the outset and in fact, in the case of K- and M-type stars, it will be able to detect planets as small as Mercury! To begin with though, we can expect the first findings to be large gas giants, as these can be confirmed relatively quickly. NASA states that such discoveries may be announced early in 2010.
You can keep up with the Kepler mission at NASA’s mission news page.