There could be one hundred billion Earth-like planets in our galaxy, a US conference has heard. Dr Alan Boss of the Carnegie Institution of Science said many of these worlds could be inhabited by simple life forms.
The Galaxy Zoo files contain almost a quarter of a million galaxies which have been imaged with a camera attached to a robotic telescope (the Sloan Digital Sky Survey, no less). In order to understand how these galaxies — and our own — formed, we need your help to classify them according to their shapes — a task at which your brain is better than even the fastest computer.
It might not look like much, but this image represents one of the most distant objects astronomers have ever seen, 12.9 billion light years away. It is a "Lyman-alpha blob" and is 55,000 light years across - as large as present-day galaxies.
Many skeptics tout an idea called the anthropic argument that claims extraterrestrial intelligence must be very rare because the time it takes for intelligent life to evolve is, on the average, much longer than the portion of a star's existence that is conducive to such life. But now astrobiologist Milan M. Cirkovic and colleagues say they've found a flaw in that reasoning.
The giant halo of dark matter that surrounds our galaxy is shaped like a flattened beach ball, researchers say. It is the first definitive measure of the scope of the dark matter that makes up the majority of galaxies' masses. The shape of this "dark matter halo" was inferred from the path of debris left behind as the Sagittarius dwarf galaxy slowly orbits the Milky Way.