Physics Photo of the Week

Physics Photo of the Week November 22, 2024 Galaxy M33 - The Triangulum Galaxy The Triangulum Galaxy (M 33) is located in the Triangulum constellation fairly close to the more famous Andromeda Galaxy in the sky, and is about the same distance from the Earth (between 2 million and 3 million light years).  The Triangulum Galaxy,  is smaller (less massive) and fainter than the Andromeda Galaxy, but it appears more delicate and seems to show more discete clouds of stars and a number of large clusters in its spiral arms.   At right is a photo of the Andromeda Galaxy, but taken with a smaller focal length telescope.  The Andromeda galaxy covers a much larger proportion of the sky (about 3 degrees across) compared with the angular size of the Triangulum galaxy (about 1/3 degree across).  Short focal length telescopes show a larger field of view than long focal length telescopes, hence the Andromeda appears smaller than the Triangulum in these telephotos.  The...

Physics Photo of the Week - November 8, 2024 Aurora from Swannanoa On May 10, 2024, much of North America experienced a "solar storm" that produced aurora as far south of the Carolinas.  Aurora (northern lights) are usually confined to the Earth's polar regions (northern Canada, Alaska, Norway, Sweeden, Russia, ...).  The aurora are produced by charged particles (electrons and protons) that are emitted by the Sun ( solar wind ) which are guided by magnetic fields in the solar system.  The Sun had emitted a massive amount of high energy electrons and protons a couple of days earlier - called a " Coronal mass ejection ".  When these particles reach the Earth, t hey strike the atoms and molecules in the Earth's upper atmosphere and cause the atmosphere to glow.  This is analogous to the glow on an old-fashioned TV picture tube when electrons strike the coating on the inside of the tube.   With a coronal mass ejection, the number of charged particles ejecte...