The Ellensburg, WA sky for the week of May 31, 2025

Saturday: You know Metis and Thebe and Adrastea and Amalthea. Io and Ganymede and Callisto and Europa. But do you recall? There are 97 Jovian moons in all. Just 60 years ago, Jupiter was thought to have only 12 moons. But astronomers are red nosed with delight that the advent of supersensitive electronic cameras has caused the number of discovered moons to rapidly increase. Jupiter’s 97 moons range in size from Ganymede, the largest in the Solar System with a diameter of 5,262 kilometers, to numerous moons with diameters of only one kilometer. In the past few years, Saturn moved to first place in the moon race with 274 moons. Uranus follows Jupiter with 28. Then comes Neptune with 16, Mars with 2, and Earth with 1. Our moon is the fifth largest in the Solar System, with a diameter of 3,475 kilometers. (One kilometer is 0.62 miles.) Even dwarf planets have moons. Pluto has 5, Eris has 1, Haumea has 2, and Makemake has 1. Eris is an outer solar system object that was discovered in 2005 and named in September of 2006. Because astronomers thought it was larger than Pluto, people called it the tenth planet for a while. (More recent measurements show Eris to be a little smaller in diameter than Pluto.) Haumea, the newest dwarf planet with a moon, was discovered in 2004 and officially named a dwarf planet on September 17, 2008. Go to https://solarsystem.nasa.gov/moons/ for more information about Solar System moons. You’ll have to wait until tonight to see our moon and to see some of the other Solar System planets that have moons.

Sunday: Venus will be as far away from the Sun in the sky as it will get this orbital cycle. This "farthest away" point is known as the planet's greatest elongation. Since Venus is in the morning sky, it is west of the Sun and this occurrence is called the greatest western elongation. This morning, Venus is one fist above due east at 4:30 a.m. Over the next few months, Venus will move toward the Sun in the sky. By late February, it will be visible in the evening sky. While you are up at this time, look to Saturn at two fists above the east-southeastern horizon.

Monday: It looks so peaceful up in the night sky. But the sky is not peaceful for Jupiter. According to a recent study by astronomers, Jupiter gets hit by a 5-20 meter diameter asteroid 10 to 65 times a year. For comparison, the object that exploded over the Russian city of Chelyabinsk in 2013 was 20 meters in diameter. Earth gets hit by a 20-meter asteroid about once every 50 years. Jupiter is a half a fist above the northwestern horizon at 9:30 p.m.

Tuesday: Summer is nearly here. How do I know? Because the days are very long. Because the temperature is rising. Because the school year is ending. Also, because the Summer Triangle is fairly high in the eastern sky at 11:30 p.m. Vega, the third brightest star visible from Ellensburg, is about five fists above the eastern horizon. Deneb, at the tail of Cygnus the swan is about three and a half fists above the east-northeast horizon. The third star in the triangle, Altair in Aquila the eagle, is two fists above the eastern horizon.

If you want to put somebody off, tell them to wait until Deneb sets. At Ellensburg’s latitude of 47 degrees, Deneb is a circumpolar star meaning it never goes below the horizon.

Wednesday: Mars is three fists above the western horizon at 10:00 p.m.

Thursday: Antares is one and a half a fists above the south-southeastern horizon at 11:30 p.m.

Friday: The bright star Capella is a half a fist above the north-northwestern horizon at 11:30 p.m. Interestingly enough, it is only about two fists from the Sun. If you viewed Capella from Ketchikan, the southernmost city in Alaska, Capella would be one and a half fists above the horizon. The Sun would be close enough to the horizon that there would be a twilight glow.

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.

The Ellensburg, WA sky for the week of May 24, 2025

Saturday: Cygnus the swan flies tonight. Deneb, the brightest star in the constellation, whose name means “tail” in Arabic, is two fists held upright and at arm’s length above due northeast at 10:15 p.m. Cygnus’ wings make a vertical line one half a fist to the right of Deneb. Its head, marked by the star Albireo, is two fists to the right of Deneb. While Deneb is at the tail of Cygnus, it is at the head of the line of bright stars. It is 160,000 times more luminous than the Sun, making it one of the brightest stars in the galaxy. It does not dominate our night sky because it is 2,600 light years away, one of the farthest naked eye stars. If Deneb were 25 light years away, it would shine as bright as a crescent moon. Compare that to Vega, its fellow Summer Triangle star. Vega IS 25 light years away and certainly doesn’t rival the light of the crescent Moon. Vega is about two fists to the upper right of Deneb.

Sunday: The bright red giant Antares is about one fist above the south-southeastern horizon at 11:00 p.m.

Monday: Altair, the lowest star in the Summer Triangle, is one fist above due east at 11:00 p.m.

Tuesday: Jupiter is a little more than a half a fist to the left of the moon at 9:30 p.m., just above the northwestern horizon.

Wednesday: Stonehenge was created on the island of Great Britain by Neolithic people. “Manhattanhenge” was created on the island of Manhattan by modern day architects and construction workers. Twice a year, at the end of May and mid-July, the setting Sun aligns perfectly with the Manhattan grid pattern. That means observers will see the Sun set at the end of the street. The first Manhattanhenge sunset is tonight at 8:13 p.m. Eastern time and then again tomorrow at 8:12 p.m. Eastern time. For more information about Manhattanhenge, go to https://www.amnh.org/research/hayden-planetarium/manhattanhenge.

Thursday: As the weather warms up, people start thinking about swimming in a nice cool body of water. A few years ago, astronomers discovered evidence of an ocean about 20 miles beneath the surface of Saturn’s moon Enceladus. NASA’s Cassini probes measured variations in how the moon’s gravity pulled on the orbiting spacecraft. These variations can be explained by a large amount of liquid water under one section of the ice because liquid water is denser than an equal volume of ice. More recently, scientists have discovered organic molecules in the geyser streaming out of cracks in the surface. Now they hypothesize that the organic molecules come from hydrothermal vents, similar to those found under Earth’s oceans, and are working on discovering the creation mechanism. For more information about these, go to https://www.universetoday.com/166987/linking-organic-molecules-to-hydrothermal-vents-on-enceladus/. While you need a very large telescope to see Enceladus, you can see Saturn at 4:15 a.m., one and a half fists above the southeastern horizon. The very bright Venus is about a half a fist above the eastern horizon at this time.

Friday: The Beehive Cluster is about a half a fist to the left of the moon at 10:00 p.m. two and a half fists above the western horizon. The Beehive Cluster, described by Ptolemy as “a nebulous mass in the breast of Cancer [the crab],” is an open star cluster of about 350 stars that is about 600 light years away.

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.

The Ellensburg, WA sky for the week of May 17, 2025

Saturday: In 1979, the group Foreigner recorded the song “Head Games”. They could have been singing about the constellations Hercules and Ophiuchus when they said “head games, it’s just you and me baby, head games, I can’t take it anymore” because the heads of these two constellations have been right next to each other in the nighttime sky for all of human history. And just to make it easy for you, a star that bears an Arabic name that means “the head” represents each head. In Hercules, it's Ras Algethi (head of the kneeler); in Ophiuchus, Ras Alhague (head of the serpent charmer). At 11:00 p.m., Ras Alhague, the brighter of the two, is about three fists held upright and at arm’s length above the east-southeastern horizon. Ras Algethi is about a half a fist to the upper right of Ras Alhague.

Sunday: The Globe at Night May campaign starts today. Globe at night is a citizen science project to quantify the impact of light pollution on our view of the night sky. Go to https://globeatnight.org/campaigns/ to learn more and participate. This is a fun way to observe the night sky and contribute to science at the same time.

Monday: Are you thirsty? I'll wait while you get some water. I will NOT wait while Corvus the crow gets you some water. The Greco-Roman god Apollo made this mistake. He sent Corvus the crow to get some water in the cup known as Crater. Some figs distracted Corvus, and he waited for them to ripen so he could eat them. When Corvus got back late, Apollo put Corvus and Crater in the sky with the gently tipping cup just out of the reach of the perpetually thirsty crow. Corvus is a trapezoid-shaped constellation about two fists above due south at 9:30 p.m. Crater is just to the right of Corvus.

Tuesday: At 9:30 p.m., Jupiter is one fist above the west-northwestern horizon and Mars is four fists above the west-southwestern horizon.

Wednesday: Are you thirsty when you get up in the morning? I know you are not waiting for Corvus. That’s okay because the Big Dipper is positioned to hold water in the morning sky. Look three fists above the northwest horizon at 4:30 a.m. You’ll see three stars that make a bent handle and four stars that make a cup. This is the Big Dipper.

Thursday: Saturn is about half a fist to the lower left of the moon, low in the east-southeastern sky at 4:30 a.m. Is that too early for you? Saturn will remain to the lower left of the moon throughout the day until it sets at about 3:00 p.m., making it a tempting target to be seen during the day. “WHAT?!” you say. “Can I really see a planet during the day?” The brightest planets, including Saturn, can be seen during the day with binoculars. The key is knowing where to look. Since you can easily find the moon during the day when it is above the horizon and not by the Sun, use it to find Saturn. First find the moon using your binoculars. Then look about half the binocular field of view to the lower left of the moon so find Saturn. Check in the morning because the Sun will not be illuminating the sky as much.

Friday: Venus is a little less than a fist to the lower left of the moon, low in the east-southeastern sky at 4:30 a.m. Is that still too early for you? Venus will remain to the lower left of the moon throughout the day until it sets at about 4:00 p.m., making it a tempting target to be seen during the day. Since Venus is brighter than Saturn, it will be even easier to see. First find the moon using your binoculars. Then look about half the binocular field of view to the lower left of the moon so find Venus. Since Venus is so bright, you may be able to still see Venus with the naked eye after you move the binoculars away.

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.

The Ellensburg, WA sky for the week of May 10, 2025

Saturday: Today is a great day to Get Intimate… Get Intimate with the Shrub-Steppe. This annual event organized by the Kittitas Environmental Education Network includes many outdoor educational activities, with most of them taking place in the Yakima River Canyon just south of Ellensburg. There are also planetarium shows at 2:00, 3:00, and 4:00 p.m. at the CWU Lydig Planetarium on the CWU campus. Go to https://www.ycic.org/giss-and-birdfest for more information about all the events. The planetarium shows are free. The planetarium is in Discovery Hall, found here: https://maps.app.goo.gl/NwpH1e5t7qXk5bfE9.

Sunday: So you think your mother has issues on Mother’s Day because she has you as a child? Her issues can’t be as bad as Cassiopeia’s issues. First, she was chained to a chair because she boasted about her beauty. Second, she must revolve around the North Star night after night. Third, a sea monster nearly killed her daughter Andromeda. Look for poor Cassiopeia about one and a half fists held upright and at arm’s length above the northern horizon at 10:00 p.m. Cassiopeia looks like a stretched out “W.”

Monday: Two of the best, and certainly the most available, tools for viewing the night sky are your eyes. Your eyes let you see the entire sky in just a few seconds. Your eyes can read star charts, decipher astronomy apps, and spot meteors while your friend is still setting up her tripod. Your naked eyes are not as effective as gathering light. They work well when the light source is comparatively bright and the detailed features are fairly large. It’s best to practice on a special Solar System body known scientifically as the Magnificent Optical Object of Nearness. Artists such as Jan van Eyck and Leonardo da Vinci produced the first realistic naked eye depictions of the Magnificent Optical Object of Nearness. I challenge you to use your unaided eyes to observe craters on the Magnificent Optical Object of Nearness, better known as the Moon. For a guide to the most prominent craters, go to http://goo.gl/JLhraO.

Tuesday: Have you ever seen a Black Hole? Neither have scientists. But they have seen the effects of a Black Hole. Black holes have a strong gravitational influence on anything that passes close to them, including light. Cygnus X-1, the first Black Hole candidate ever discovered, is two fists above the east-northeastern horizon at 7:00 p.m., in the middle of the neck of Cygnus the swan. NASA launched the Chandra X-ray observatory in 1999 to study black hole candidates and other high-energy events.

Wednesday: At 9:30 p.m., Jupiter is about one fist above the west-northwestern horizon and Mars is four and a half fists above the west-southwestern horizon.

Thursday: If someone gives you a ring and says, “this ring symbolizes our eternal love, just like the rings of Saturn are eternal,” don’t doubt their love. But do doubt their astronomy knowledge. According to data recently analyzed from the Cassini Mission, Saturn’s rings may be only 10 to 100 million years old. As Cassini passed between Saturn and the rings, it was able to get the best estimate yet of the mass of the rings. Saturn’s rings are made mostly of ice and are still very bright and clean. Older rings would be darkened by debris. Also, the ring particles get pulverized by collisions over time. If this relatively low mass of ring particles were older, they would have been destroyed by now. For more information about the lifespan of Saturn’s rings, go to Saturn’s rings https://www.universetoday.com/141272/saturns-rings-are-only-10-to-100-million-years-old/.  Saturn and its young rings are about one fist above the eastern horizon at 4:30 a.m. The bright planet Venus is half a fist above the eastern horizon at this time.

Friday: I am guessing that some of you don’t like the line of reasoning from Tuesday: that seeing the effects of a Black Hole is good enough to claim there are Black Holes. You have never seen the wind. But you have seen the effects of the wind. And no Ellensburg resident doubts the existence of the wind.

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.

The Ellensburg, WA sky for the week of May 3, 2025

Saturday: The Eta Aquarid meteor shower peaks just before dawn this weekend. Since this meteor shower has a fairly broad peak range, you should start looking before dawn every morning this week. The moon is close to the first quarter phase near the peak so it will have set, meaning even dimmer meteors will be visible. Meteor showers are named after the constellation from which the meteors appear to originate. The meteors appear to come from a point in the constellation Aquarius near the star Eta. This point is about one fist held upright and at arm’s length above the east horizon at 4:00 a.m. The Eta Aquarid meteors slam into the Earth at about 40 miles per second. They often leave a long trail. The Eta Aquarid meteors are small rocks that have broken off Halley’s Comet. For more information about the Eta Aquarids, go to http://earthsky.org/?p=158833.

Sunday: Jupiter is about two fists above the west-northwestern horizon at 9:00 p.m.

Monday: “Lately, I’ve been, I’ve been losing sleep. Dreaming about the things that we could be. But baby, I’ve been, I’ve been praying hard, said no more counting dollars. We’ll be counting 9,096 stars, yeah, we’ll be counting 9,096 stars.” Luckily, artistic judgment prevailed over scientific precision in the OneRepublic hit “Counting Stars.” According to the Yale Bright Star Catalog, there are 9,096 stars visible to the naked eye across the entire sky if you are observing from a very dark site. In the northern United States, where a part of the sky is never visible, that number drops to about 6,500. In the middle of a small city at mid-latitudes, like Ellensburg, that number drops to a few hundred. No wonder someone has been losing sleep. Learn more about the star count at http://goo.gl/nt8d80.

Tuesday: Venus is about a half a fist above the eastern horizon at 4:45 a.m. Saturn is about a half a fist to the right of Venus.

Wednesday: Give me an “M.” Give me a “3”. What does that spell? “M3.” “Big deal,” you say. It was a big deal to French comet hunter Charles Messier (pronounced Messy A). M3 was the 3^rd comet look-alike that Messier cataloged in the late 1700s. M3 is a globular cluster, a cluster of over 100,000 stars that is 32,000 light years away. It is too dim to be seen with the naked eye but is fairly easy to find with binoculars. First find Arcturus five and a half fists above due southeast at 10:30 p.m. Move your binoculars up one binocular field of view so two stars of nearly identical brightness are in your field of view. When the top star is in the lower left part of your field of view, there should be a fuzzy patch near the center of your field of view. This is M3.

Thursday: Mars’ two small moons, Phobos and Deimos, are not visible in typical backyard telescopes. But they are an interesting study. The former view among astronomers was that both moons are captured asteroids. That makes sense given Mars’ proximity to the asteroid belt. But recent findings by European astronomers indicate that Phobos is very porous and made of material like the surface of Mars. This implies that Phobos may consist of chunks of Martian debris that was blasted off by numerous impacts and gravitationally bound together. Unfortunately, the Russian Phobos-Grunt probe launched late 2011 to collect material from Phobos crashed to Earth after malfunctioning. For more information about this recent model of Phobos’ formation, go to https://sci.esa.int/web/mars-express/-/31031-phobos. For more information about Mars, look four fists above the west-southwestern horizon at 10:00 p.m.

Friday: This weekend, celebrate Mother’s Day with the big mom of the sky, Virgo. Ancient Greeks and Romans associated this portion of the sky with their own goddess of the harvest, either Demeter (Greeks) or Ceres (Roman). Demeter was the mother of Persephone and Ceres was the mother of Proserpina. According to myth, each of these daughters was abducted causing their mothers great grief. The first star in Virgo rises in the afternoon. Spica, the bright bluish star in the constellation rises at 7:00 p.m. and is three fists above the south-southeastern horizon at 10:00 p.m.

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.