Western Isles rock offers potential clue to life on Mars
Analysis of rocks in the Western Isles has provided "a tantalising clue" that Mars may contain habitats which can potentially support life. Scientists from Scotland, Canada and US, said their studies of rocks on Barra and the Uists showed that hydrogen was formed after earthquakes. Hydrogen is essential for supporting life, the researchers said. The scientists said on Mars there are "Marsquakes" which may produce hydrogen in the same way as quakes on Earth. Read more
Traces of life on Mars may have been bleached away
A Martian meteorite that has been frozen in Antarctic ice hints that the surface of the Red Planet is riddled with chemicals related to those used in household bleach. That increases the likelihood that carbon-bearing compounds - strong indicators of life - may have been broken down by chemical reactions, suggesting that we need to dig deeper into Mars to search for traces of any past inhabitants. Read more
New evidence from meteorites suggests that the basic building blocks of life are present on Mars. The study found that carbon present in 10 meteorites, spanning more than four billion years of Martian history, came from the planet and was not the result of contamination on Earth. Details of the work have been published in the journal Science. Read more
Craters made by asteroid impacts may be the best place to look for signs of life on other planets, a study suggests. Tiny organisms have been discovered thriving deep underneath a site in the US where an asteroid crashed some 35 million years ago. Scientists believe that the organisms are evidence that such craters provide refuge for microbes, sheltering them from the effects of the changing seasons and events such as global warming or ice ages. Read more
The "desert varnish" that blackens Earthly rocks may be made by bacteria. So what about similarly shiny rocks on Mars?
When NASA's Viking landers touched down on Mars, they were looking for signs of life. Instead, all their cameras showed was a dry, dusty - and entirely barren - landscape. Or so it seemed. But what the 1976 Viking mission, and every subsequent one, saw was a scene littered with rocks coated with a dark, highly reflective sheen. That coating looks a lot like a substance known on Earth as "rock varnish", found in arid regions similar to those on Mars. The latest evidence hints that rock varnish is formed by bacteria. Could there be microbes on Mars making such material too? Read more
Martian life appears less likely, study reveals If there's any life on Mars, it's not likely to exist on or just below the planet's surface, concludes a new study of Mars' mysterious methane, a gas which on Earth is tied to biological processes. The discovery of rich plumes of methane on Mars earlier this year fed theories that the planet could host underground colonies of micro-organisms. However, rapid destruction of methane suggests that the planet's environment may be too hostile to support life.
U.S. space agency scientists said the area where the Phoenix Mars Lander touched down last year might be a favourable environment for microbes. The NASA experts said their hypothesis was based on favourable chemistry and episodes with thin films of liquid water during ongoing, long-term climate cycles.
Scientists using Earth-based telescopes have taken detailed measurements of the gas methane on Mars, a finding that supports the possibility of underground life. The scientists, from NASA and other U.S. institutions, found high concentrations of methane that are consistent with methane plumes produced by underground bacteria on Earth. The observations have reignited a life-on-Mars debate that began in 1996 when NASA astrobiologist David McKay and several other colleagues announced that a meteorite from Mars contained evidence of bacteria.
Plumes of methane gas detected over certain locations on Mars in 2003 could point to active geological processes on the red planet, or perhaps even to methane-burping microbes deep below the Martian surface, a new study reports. Methane, a small (but important) constituent of Earth's atmosphere, makes up an even smaller percentage of Mars' atmosphere (which is 95 percent carbon dioxide), so detecting it on the red planet is a rare event.
A surprising and mysterious belch of methane gas on Mars hints at possible microbial life underground, but also could come from changes in rocks, a new NASA study found. The presence of methane on Mars could be significant because by far most of the gas on Earth is a byproduct of life - from animal digestion and decaying plants and animals. Past studies indicated no regular methane on Mars. But new research using three ground-based telescopes confirmed that nearly 21,000 tons of methane were released all at once during the late summer of 2003, according to a study published Thursday in the online edition of the journal Science.