Spiral galaxies make up about 70 percent of all observed galaxies, some with large central bulges and tightly wound spiral arms like a fast-spinning ice skater, some with more wide-open arms and smaller bulges and some in various in-between states. NGC 2008, seen here in an image captured by the Hubble Space Telescope, is an Sc galaxy, with S signifying its spiral form and c indicating a small central bulge. The galaxy, located about 425 million miles from Earth in the constellation Pictor, was discovered in 1834 by astronomer John Herschel.
This striking NASA/ESA Hubble Space Telescope image depicts the low surface brightness (LSB) galaxy known as UGC 477, located just over 110 million light-years away in the constellation of Pisces. LSB galaxies appear to be dominated by dark matter, making them excellent objects to study to further our understanding of this elusive substance.
Due for launch in 2020, ESA’s Euclid satellite will set astronomers a huge challenge: to analyse 100,000 strong gravitational lenses. The gravitational deflection of light from distant astronomical sources by interposing massive galaxies can create multiple images of the source that are not just visually stunning, but are also valuable tools for probing our universe.