Gliese 581g (also known as Zarmina) is 20 light years away from us in the constellation Libra. Astronomers used the HIRES spectrometer on the Keck I Telescope to observe the Giliese system. For a while it was known as the potentially habitable “second Earth”, though some astronomers questioned its very existence. Now Gliese 581g is back on the list of exoplanets considered prime candidates for harbouring life – along with another planet orbiting the same star. Gliese 581g was discovered by astronomers of the Lick-Carnegie Exoplanet survey in 2010, but subsequent surveys were unable to detect it.
This infographic is of every mission to Mars ever. As you can see, probes to Mars often fail; as of July 2012, the success rate was 47%. It was the Soviet Union that first sent unmanned space probes to Mars; many failed. In 1971 the lander Mars 2 became the first object from Earth to reach the surface of Mars (unfortunately it crashed). The Mars 3 lander did land on Dec 2, 1971, and transmitted data before falling silent. The Viking 1 and 2 landers not only reached Mars’ surface in 1976, but also gathered soil samples for analysis and took many photos. In 1997 the Mars Pathfinder released Sojoiner onto the Martian surface, which it explored for nearly three months before contact was lost. A high res version is in the link below.
An international team of astronomers, led by Dr Aaron Robotham of the International Centre for Radio Astronomy Research (ICRAR), and the University of St Andrews in Scotland, searched for groups of galaxies similar to ours in the Galaxy and Mass Assembly survey (GAMA).
Simulations of how galaxies form have so far not shown many examples similar to the Milky Way and its surrounds, suggesting they would be a rare occurrence. How rare had not been established until now though, with the discovery of two exact matches amongst the hundreds of thousands of galaxies surveyed. About 3% of galaxies similar to the Milky Way have companion galaxies like the Large and Small Magellanic Clouds; there are 14 galaxy systems similar to ours but only two of those are an exact match.