Tuesday, February 13, 2018
The Ellensburg WA sky for the week of 2/17/18
Saturday: Orion stands tall in the southern sky. At 7:30 p.m., the middle of Orion’s belt is four fists held upright and at arm’s length above due south. And talk about belt tightening! Alnilam, the middle star in the belt, is losing mass at a rate of about 100 thousand trillion tons a day. That’s a 1 followed by 17 zeros tons per day.
Sunday: “Happy Birthday to you. Happy Birthday to you. Happy Birthday dear Pluto. Happy Birthday to you.” On this day in 1930, Clyde Tombaugh discovered Pluto, at that time classified as the ninth planet. However, as astronomers started discovering a lot of similar objects in that part of the solar system, they realized that had a classification crisis on their hands. Should everything in this region of the solar system be named a planet? Eventually the International Astronomical Union (IAU) reclassified Pluto and all future Pluto-like objects as dwarf planets.
Monday: At 6 a.m., Mars is two fists above the south-southeast horizon, less than a fist to the upper left of its rival Antares. Dogg may have tried to put an end to the East Coast-West Coast rap rivalry. But the Mars-Antares rivalry has been going on for centuries. In fact, the name Antares means "rival of Mars". The reddish Antares has that name because of its resemblance to the reddish Mars.
Tuesday: Clyde Tombaugh discovered the first planet 9. Will you discover the new Planet 9? You and thousands of others will have the opportunity to comb through images of the sky from NASA’s Wide-field Infrared Survey Explorer (WISE). You’ll view short “flipbook” movies of the same patch of sky on different nights. Any point of light that moves could be Planet 9 or another undiscovered Solar System object. Read about how you can join the search for Planet 9 at https://goo.gl/D4PkCD.
Wednesday: The Stargate movies and TV shows have access to a portal to other planets. Harry Potter has access to a portal to the Chamber of Secrets. You have access to a Portal to the Universe. This portal is not in Moaning Myrtle’s bathroom but is on the web at http://www.portaltotheuniverse.org/. It is a repository of up-to-date astronomy news, blogs, and podcasts. A recent story highlights how planet hunters like you and Clyde Tombaugh study the galaxy to learn more about other planets. The first planets orbiting TRAPPIST-1 were discovered in 2016. Recent measurements of the densities of the planets indicate that they could have significant amounts of water, up to 5% of the planet's mass in some cases. Only 0.02% of the mass of the Earth is water. For more information about water on the TRAPPIST planets, go to https://goo.gl/u5tPUK.
Thursday: The Seven Sisters are playing coy with the Moon tonight. At 9 p.m., they are about a fist to the upper right of the Moon. Close enough to show their interest but far enough to show their independence. Oh, by the way, the Seven Sisters is another name for the Pleiades, an open star cluster of about 1,000 middle-aged, hot B-type stars.
Friday: At 6 a.m., Jupiter is two and a half fists above the south horizon and Saturn is about a fist above the southeast horizon.
The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to https://nightsky.jpl.nasa.gov/planner.cfm.