Is or was there life on Mars? That is one of the biggest and most hotly debated questions in planetary science. The manner in which the evidence has been searched for is also a topic of much discussion. The Viking landers in the 1970s were the first to look for direct evidence for microbial life still existing in the Martian soil, and the results are still regarded as inconclusive, with both pro and con supporters debating whether the landers actually found living microbes or just unusual soil chemistry. Subsequent lander and rover missions have focused more on determining whether conditions in Mars’ ancient past were habitable and able to support life as we know it, rather than searching directly for evidence of past or present life itself.
Category Archives: Astrobiology
A recent discovery by scientists may have implications for possible extraterrestrial life: Bacteria have been found thriving in a lake of oil in Trinidad, again showing how life can exist in even the most inhospitable conditions on Earth. The discovery brings to mind the similar environment on Saturn’s moon Titan, where lakes and seas of liquid hydrocarbons (methane/ethane) exist at the moon’s poles.
Astronomers have discovered the oldest known (so far) exoplanet which might be capable of supporting life; the planet, Kapteyn b, is likely more than twice the age of the Earth. The planet was found by an international team of astronomers, led by Guillem Anglada-Escude from Queen Mary University.
Exoplanets orbiting distant stars are now being discovered in the thousands, with a new discovery made almost every week now. But what about exomoons? In our own solar system, moons far outnumber planets, so it should be considered likely that many of those other planets out there would also have moons. The problem is size; moons tend to be much smaller than planets in most cases, so detecting them orbiting such far away worlds is very difficult. Thankfully, however, technology is now at the point where just such detections should begin to be possible. A new technique how now been proposed that could allow astronomers to bring exomoons from theoretical concepts to reality.
Europa and Enceladus, for good reason, have captured the attention and imagination of those searching for evidence of life elsewhere in our Solar System. Both moons are now thought to have subsurface oceans with conditions where life could possibly exist, as well as Jupiter’s moon Callisto. Saturn’s largest moon Titan may also have an ocean beneath its extremely cold surface of rock-hard ice and liquid methane seas and lakes. There is another moon with evidence for a similar ocean as well, Ganymede, but until now this ocean has been considered less likely to be able to support life. New findings, however, are now causing scientists to re-evaluate this possibility.
Today was another big day for those interested in space exploration, and the search for other Earth-like alien worlds in particular – the first Earth-sized exoplanet orbiting another star in the habitable zone has been discovered, it was announced by astronomers with the Kepler space telescope mission.
Coming just after the news of the ringed asteroid and new dwarf planet, some more exciting news from the outer Solar System was announced last Thursday, and this will be of particular interest to those hoping to find evidence of alien life elsewhere in our solar system. Saturn’s tiny moon Enceladus, famous for its geysers of water vapour spewing out into space, has long been suspected of harboring an internal ocean, just like Jupiter’s moon Europa (and possibly others). Now it seems that scientists have the evidence they’ve been looking for, thanks to new findings based on data returned by the Cassini spacecraft, still in orbit around Saturn.
For scientists and space enthusiasts who have been advocating a mission to Jupiter’s moon Europa, there was some good news this week from NASA. A mission to Europa has been officially included in the NASA 2015 Budget request. The inclusion is a reason for cautious optimism; while naming it as a target for a future robotic mission in the 2020s, NASA also wants to do that mission as cheaply as possible. Given the current economic climate, that may not be surprising, but what would reduced cost mean in terms of science?