Comet Enthusiast

People used to think that the heavens were a vast clockwork, with planets and moons moving in circular orbits like a vast timepiece.  Recent advances have shown us that this stellar machinery is far vaster than they ever suspected - even our galaxy has satellites, mini-galaxies orbiting the Milky Way and some of them could be very interesting indeed.

Although dark matter doesn't emit or absorb light, scientists can measure its gravitational effect on ordinary matter and believe it makes up about 85 percent of the total mass in the universe. Finding ultra-faint galaxies like Segue 1, which is so rife with dark matter, provides clues as to how galaxies form and evolve, especially at the smallest scales.