The Ellensburg, WA sky for the week of June 21, 2025

Saturday: At 7:40 p.m. last night, the Sun reached its highest declination (the official name for sky latitude) of 23.5 degrees above the celestial equator. The celestial equator is the line that divides the northern sky from the southern sky. That makes today the first full day of summer. In Ellensburg, the Sun is about seven fists held upright and at arm’s length above the south horizon at 1:00 p.m. (noon standard time) on the first day of summer.

Contrary to popular belief, the Sun is never straight overhead in Ellensburg or anywhere else in the 48 contiguous states. The northernmost portion of the world where the Sun can be directly overhead is 23.5 degrees north latitude. In ancient times, the Sun was in the constellation Cancer the crab on the first day of summer. Hence, 23.5 degrees north latitude has the nickname "Tropic of Cancer". Because the Earth wobbles like a spinning top, the Sun's apparent path through the sky changes slightly over time. Now, the Sun is in the constellation Taurus the Bull on the first day of summer. However, citing the high cost of revising all the science books, geographers are not changing the name of 23.5 degrees north latitude to "Tropic of Taurus". The first day of summer is often called the summer solstice. However, astronomers refer to the summer solstice as the point in the sky in which the Sun is at its highest declination above the celestial equator. Summer starts when the Sun is at the summer solstice point.

Sunday: Mercury is a half a fist above the northwestern horizon at 10:00 p.m. The two bright stars of Gemini, Pollux and Castor, are to the right of Mercury. At this time, Mars is about two first above the western horizon. The bright star Regulus is to the lower right of Mars.

Monday: Antares is one and a half fists above the southern horizon at 11:30 p.m.

Tuesday: “Mom, I can’t sleep. It is too light out!” A poor excuse you say. Good astronomy skills, I say. The latest sunset of the year happens around this date. Surprisingly, the earliest sunrise and the latest sunset do not both happen on the longest day of the year, the day of the summer solstice. The earliest sunrise occurs just before the longest day and the latest sunset occurs just after the longest day. This phenomenon relates to the angle of the Sun’s path near rising and setting. In Ellensburg, that angle is about 66 degrees above the southern horizon at noon near the first day of summer. Because of the Earth’s orbit, which causes the Sun’s apparent motion, the angles are not symmetric. The asymmetry in orbital angles leads to the asymmetry in rise and set times. This year, the sun sets at about 9:01 p.m. every night this week as viewed from Ellensburg, WA. Find sunset data for your location at https://www.timeanddate.com/sun/.

Wednesday: Venus is one fist above the eastern horizon and Saturn is nearly three fists above the southeastern horizon at 4:00 a.m.

Thursday: Happy Asteroid Day (http://www.asteroidday.org/), the day we celebrate avoiding the destruction of the Earth by an undiscovered asteroid. There are about a million asteroids in the Solar System with the potential to strike Earth and destroy a city. Astronomers have discovered only 1% of them. Asteroid Day is an effort to educate the public and encourage policy makers to fund this important effort. King Tut may have celebrated an ancient Asteroid Day by asking his assistants to make a dagger out of a broken-off asteroid that landed on Earth. Astronomers discovered that the blade of the knife contained much more nickel than is found in terrestrial iron, an amount consistent with iron meteorites, especially with one found in the year 2000 in the Kharga region in northern Egypt. For more information about the dagger, go to http://goo.gl/BHBivd.

Friday: Don’t wait until next week to watch those wimpy firecracker shows. Find the hypergiant star Rho Cassiopeiae. Astronomers think that Rho Cassiopeiae will likely go supernova (explode) in the near future. Of course, for stars, “near future” might mean today. It might mean 20,000 years from now. Rho Cassiopeiae is in the constellation Cassiopeia the queen. At 11:00 tonight, Cassiopeia looks like the letter “W” about two and a half fists above the north-northeastern horizon. Rho Cassiopeiae is about a finger’s width to the right of the rightmost star in the “W.” Once you find it, you’ll be thinking, “Big deal, I can hardly see it.” Although it is barely visible to the naked eye, it is actually very bright. It is the 20^th most luminous star in the sky, a whopping 550,000 times more luminous than the Sun.

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. All times are Pacific Time unless noted.