This is the Dudley Observatory Skywatch Line for Wednesday, October 24th, and Thursday, October 25th, written by Louis Suarato.
The Full Hunter’s Mon occurs at 12:45 p.m. Wednesday, and rises at 6:25 p.m. in the constellation Cetus. Cetus is the fourth largest constellation, and is visible from September through January. This huge constellation only contains a few bright stars, and its size makes it difficult to discern its shape. Cetus is the home of the first variable star to be discovered, Mira. Over a period of 332 days, Mira varies in brightness from magnitude 2.0 to magnitude 10.0. Discovered by David Fabricus in 1596, Mira’s name is derived from the Latin word for ”wonderful”. Thursday night, use binoculars to view the Pleiades star cluster five degrees below the waving gibbous Moon.
Mars and Saturn are your best opportunities for viewing planets these nights. Look high over the southern horizon after 7:30p.m. for Mars, and over the southwest horizon for Saturn. Last weekend, the European and Japanese space agencies collaborated to launch an Ariane 5 rocket, carrying two spacecraft to Mercury. The spacecraft are not expected to be captured by Mercury until December 2025. In order to accomplish this, BepiColombo must make several flybys of Earth, Venus, and Mercury to slow it down before reaching the Sun’s strong gravitational pull. The two spacecraft will gather data regarding planetary evolution, and the effects of the solar wind on Mercury. The Japanese spacecraft, Mio, will be carrying out the solar wind analysis. The planetary evolution analysis will be compiled by the European Mercury Planetary Orbiter.
If you look north at astronomical twilight, about an hour and half past sunset, when the Sun is 18 degrees below the horizon, you’ll notice the Big Dipper low and parallel to the horizon. This is the position of the Big Dipper beginning each night of the Autumn months. During the winter months, the Big Dipper will begin the night in the 3 o’clock position relative to the North Star, Polaris. Come Spring, the Big Dipper begins the night at 12 o’clock, and in the Summer, this well-known asterism begins the night in the 9 o’clock position.