There are many galaxies of different shapes and sizes around us today. Roughly half are gas-poor elliptical-shaped galaxies with little new star formation activity, and half are gas-rich spiral and irregular galaxies with high star formation activity. Observations have shown that gas-poor galaxies are most often found near the centre of crowded galaxy clusters, whereas spirals spend most of their lifetime in solitude.

An international team of astronomers using NASA's Hubble Space Telescope has created the first three- dimensional map of the large-scale distribution of dark matter in the universe.

New observations from NASA's Hubble Space Telescope have begun to fill gaps in the early stages of planet birth.