The Ellensburg, WA sky for the week of July 3, 2021

Saturday: Venus is a half a fist held upright and at arm’s length above the west-northwestern horizon at 10:00 p.m. Mars is about a half a fist to the upper left of Venus.  Venus doesn’t have tectonic plates like Earth does. But that doesn’t mean that its surface is static. Planetary scientists have been studying a Venus lowland that moves like blocks of ice on a frozen lake. While more data is needed, this seems to be a type of crust activity that is between a solid crust and a planet with plate tectonics. For more information about this, go to https://skyandtelescope.org/astronomy-news/venus-surface-is-fragmented-like-pack-ice/.

Sunday: The bright supergiant star Antares is one and a half fists above the southern horizon at 10:30 p.m.

Monday: Hot enough for you? Don’t blame the Earth-Sun distance. Surprisingly, the overall temperature of the Earth is slightly higher in July, when the Earth is farthest from the Sun, than in January, when it is closest. That’s because in July, the Northern Hemisphere is tilted towards the Sun. (This is the real cause of the seasons.) The Northern Hemisphere has more land than the Southern Hemisphere. Thus, in July, the large amount of Northern Hemisphere land heats up the entire Earth about two degrees Celsius warmer than in January. In January, the watery Southern Hemisphere is tilted toward the Sun. But, water does not heat up as fast as land so the Earth is a few degrees cooler. The distance between the Earth and the Sun is its greatest tomorrow, 152.1 million kilometers. This is called aphelion from the Greek prefix “apo” meaning “apart” and Helios, the Greek god of the Sun.

Tuesday: Look straight up at midnight. The head of Draco the dragon will be looking straight down on you. The brightest star in the head is called Eltanin. If you wait for a VERY long time, Eltanin will be the brightest star in the entire night sky. Currently 154 light years away, it is moving towards Earth and will be only 28 light years away in about 1.3 million years, claiming the title as the brightest star.

Wednesday: Saturn is one fist above the southeastern horizon and Jupiter is a half a fist above the east-southeastern horizon at midnight.

Thursday: Being in a coma is a bad thing. Looking at the Coma Star Cluster is a good thing. The Coma Star Cluster is an open cluster of about 50 stars that takes up more space in the sky than 10 full Moons. It looks like a fuzzy patch with the naked eye. Binoculars reveal dozens of sparkling stars. A telescope actually diminishes from the spectacle because the cluster is so big and the telescope’s field of view is so small. The Coma Star Cluster is in the faint constellation Coma Berenices (ba-ron-ice’-ez) or Queen Berenice’s hair. Queen Berenice of Egypt cut off her beautiful hair as a sacrifice to the gods for the safe return of her husband Ptolemy III from battle. The Coma Star Cluster is about three fists above the western horizon at 11:00 p.m. 

Friday: Mizar is a star in the middle of the Big Dipper handle. Don’t confuse Mizar with its rhyming brother Izar in the constellation Bootes. Izar is also a binary star with about the same apparent brightness. And both were featured in different episodes of Star Trek. Izar was featured in the Star Trek episode “Whom Gods Destroy” from the original series. It is the base of Fleet Captain Garth, a former big shot in the federation and one of Kirk’s heroes before he went insane. Garth kidnaps Kirk and Spock before eventually being outsmarted. Mizar doesn’t play as big a role in its episode. It is the star of the homeworld of one of the alien species in The Next Generation episode “Allegiance”. Izar is one fist above the bright star Arcturus and five and a half fists above the west-southwestern horizon at 11:00 p.m. Mizar is five and a half fists above the northwest horizon at this time.

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.