The Milky Way is populated with planets
31 August 2022
The word Milky Way is a translation of the Latin word via lactea, derived from the Greek γαλακτικός κύκλος (galacticos kýklos), meaning “milky ring.” In 1610, Galileo Galilei used a telescope to see this band of light. First resolved it into individual stars; until the early 1920s, most astronomers believed that the Milky Way contained all the stars . After a debate between Harlow Shapley and Heber Curtis in 1920, Edwin Hubble’s observations revealed that the Milky Way is simply one of the multiple galaxies.
The Milky Way is a secured spiral galaxy with an evaluated visible light diameter of 100,000-200,000 light-years. Recent simulations suggest that the dark matter region containing several visible stars may extend to nearly 2 million light-years in diameter . The Milky Way has many satellite galaxies and is part of the Local Group galaxy, a Laniakea supercluster, and the Virgo supercluster.
The solar method is discovered at a radius of about 27,000 light years from the galaxy’s center, at the inner edge of the Orion Arm, a spiral of gas and dust. The stars in the innermost ten thousand light-years form a bulge, from which one or more bars radiate out. At the galactic center is an intense radio source called Sagittarius A*, a supermassive black void of 4.100 (± 0.034) million solar assemblies . Stars and gases at wide distances from the galactic center are orbiting at about 220 km/s. The constant rotational speed appears to violate the laws of Keplerian mechanics, suggesting that much of the mass of the Milky Way (about 90%) neither emits nor absorbs electromagnetic radiation, making it invisible to telescopes. The rotation period is about 240 million years at the radius of the Sun, and the Milky Way as a full is rolling at about 600 km per second relative to its extragalactic frame of reference. The oldest stars in the Milky Way are about the same age as the universe itself and were probably formed shortly after the dark ages of the Big Bang.