A galaxy is a massive system bound together by gravity that contains stars and surrounding matter, stellar remnants, interstellar matter, and dark matter, all orbiting a common center of gravity. Typical galaxies range from as few as 10 million stars up to supergiants with 100 trillion stars, but most of the mass is dark matter. The Solar System is in the Milky Way galaxy, whose nearest large neighbor, the Andromeda Galaxy, is about 750,000 parsecs (2.4 million light years) away from Earth; the two galaxies dominate the Local Group. There are probably more than 200 billion galaxies in the observable universe. Most are 1,000 to 100,000 parsecs (about 3,000 to 300,000 ly) in diameter and are often separated from their neighbors by millions of parsecs. There is evidence that supermassive black holes exist at the center of many, if not all, galaxies. The Milky Way, a spiral galaxy with a diameter of at least 26,800 parsecs (87,400 ly), has such an object at the Galactic Center. ( Full article... )
March 2 : Fast of Esther (Judaism, 2026); Adwa Victory Day in Ethiopia, Independence Day in Texas
| | Haliotis jacnensis , commonly known as the Jacna abalone, is a species of sea snail in the abalone family, Haliotidae. It is found in the western Pacific Ocean at depths between sea level and 50 metres (160 ft), around the coasts of American Samoa, Fiji, Guam, Indonesia, Japan, Micronesia, New Caledonia, Niue, the Northern Mariana Islands, the Philippines, the Solomon Islands, Tonga, Tuvalu and Vanuatu. H. jacnensis features an oblong–ovate shell that varies in size between 7 to 25 millimetres (0.28 to 0.98 in). The shell is reddish-orange with a silvery interior and features irregular scaly ridges. This picture shows five views of a H. jacnensis shell, 18 millimetres (0.71 in) in length, found on Masbate Island in the Philippines. Photograph credit: H. Zell Recently featured: |