- Three billion years ago, life on Earth was simple. Single-celled organisms ruled, and there wasn’t much to them. They were what we now call prokaryotic cells, which include modern-day bacteria and archaea, essentially sacks of loose molecular parts. They swirled together in shallow, primordial brews or near deep-sea ocean vents, where they extracted energy from the environment and reproduced by dividing one cell into two daughter cells. Then, one day, that wilderness of simple cells cooked up something more complex: the ancestor of all plants, animals and fungi alive today, a cell type known to us as the eukaryote
- Messier 81 (Wikipedia)
Messier 81 (also known as NGC 3031 or Bode’s Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of 29.44 kiloparsecs (96,000 light-years). Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M☉ supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy’s large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.