What's up in the Ellensburg, WA sky for the week of April 29, 2023

Saturday: The bright star Regulus is a half a fist to the lower right of the moon at 9:00 p.m., high in the southern sky.

Sunday: The Eta Aquarid meteor shower peaks just before dawn on May 5, 6, and 7. 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 full moon phase near the peak, meaning all but the brightest meteors will be obscured. 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.

Monday: At 10:00 p.m., Venus is nearly two fists above the west-northwestern horizon and Mars is three and a half fists above due west.

Tuesday: “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.

Wednesday: The bright star Spica is less than a half a fist to the lower right of the moon at 9:00 p.m. in the southeastern sky.

Thursday: It is often said that Earth is a water world because about 70% of the Earth’s surface is covered by water. What would it look like if all that water on the surface were gathered up into a ball? That “ball” would be about 700 km in diameter, less than half the diameter of the Moon. The Astronomy Picture of the day shows us right here https://apod.nasa.gov/apod/ap120515.html.

Friday: Saturn is one and a half fists above the southeastern horizon at 5:00 a.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.

What's up in the Ellensburg, WA sky for the week of April 15, 2023

Saturday: This week is International Dark Sky Week. Check out the schedule of events at https://idsw.darksky.org/, including many presentations that are broadcast live so you can interact with the presenter. But that doesn’t mean that we can ignore our obligation to minimize stray light for the next 51 weeks. Lights that are aimed upward illuminate the atmosphere and obscure dim objects. Having too much light shining where it shouldn’t is considered light pollution. And just like other forms of pollution, light pollution can be hazardous to our health and the health of other animals. That’s right. Harmful. Watch this National Geographic video for more information: https://youtu.be/V_A78zDBwYE.

Sunday: The waning crescent moon is just above the east-southeastern horizon at 5:30 a.m. Saturn is a half a fist held upright and at arm’s length to the upper right of the moon.

Monday: “The crow rises in the southeast,” said spy number one. “I’m sorry. I don’t recognize that code,” replied spy number two. Spy one exclaimed, “That’s because it’s not a code, you idiot. I’m talking about the constellation Corvus the crow.” This very bad spy movie dialogue is to remind you that Corvus had a very bad life. According to one myth, Corvus brought the god Apollo the news that his girlfriend was seeing someone else. In a classic case of punishing the messenger, Apollo turned the formerly beautifully colored crow black. The box shaped Corvus is one fist above the southeastern horizon at 9:00 p.m.

Tuesday: At 9:00 p.m., very bright Venus is two and a half fists above the western horizon and Mars is five fists above the west-southwestern horizon.

Wednesday: There is an annular solar eclipse in Southeast Asia and Australia in the middle of the day April 20 local time but about 9:00 tonight Pacific Daylight Time. In this case “annular” does not mean yearly occurrence. Annular refers to the ring shape of the Sun. The Moon will be directly between the Earth and the Sun. But it will be relatively far from the Earth meaning it will not appear large enough to fully block the Sun. If you want to read about the eclipse, see a simulation, or watch a live stream, go to https://www.timeanddate.com/eclipse/solar/2023-april-20. This is one of my favorite astronomy websites.

Thursday: Do people think you have a magnetic personality? The star Cor Caroli understands how you feel. Cor Caroli has one of the strongest magnetic fields among main sequence stars similar to our Sun. This strong magnetic field is thought to produce large sunspots that cause the brightness of Cor Caroli to vary. Cor Caroli is nearly straight overhead at midnight.

Friday: Remember the old saying: April showers bring… meteors. The Lyrid meteor shower peaks this week, with the peak of the peak occurring tonight and tomorrow night before midnight. The meteors appear to come from a point to the right of the bright bluish star Vega in the constellation Lyra the lyre. This point is about three fists above the east-northeast horizon at midnight tonight and close to straight overhead near dawn. The best time to observe the shower is between 11:00 p.m. and moonrise at about 3:00 a.m. Typically, this is one of the least interesting major meteor showers of the year, with 10-20 bright, fast meteors per hour. However, it is also one of the most unpredictable. As recently as 1982, there were 90 meteors visible during a single hour. In addition, the Lyrid meteor shower has historical interest because it was one of the first ones observed. Chinese records say “stars fell like rain” in the shower of 687 B.C. As your mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. Meteors are tiny rocks that hit the Earth and burn up in the atmosphere. For more information, go to http://earthsky.org/?p=158735.

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.

The Ellensburg, WA sky for the week of April 8, 2023

Saturday: The first day of spring was March 20. The most recent full moon was April 6. That means tomorrow is Easter. The standard way to determine the date of Easter for Western Christian churches is that it is the first Sunday after the full moon that occurs on or after the vernal equinox, also known as the first day of spring. Of course, the other standard way is to look for the date of church services celebrating the resurrection of Jesus. There is no Bible story of an “Easter star”. If there were, Spica would be a pretty good choice. The name Spica comes from the Latin “spica virginis” which means “Virgo’s ear of grain”. Spica represents life-giving sustenance rising after a long winter just like the risen Jesus represents life-giving redemption to Christians. Spica is one and a half fists held upright and at arm’s length above the southeastern horizon at 10:00 p.m. To learn how to calculate the exact date of Easter for any year, go to https://www.assa.org.au/edm.

Sunday: For the next few nights, Venus will be moving by The Pleiades open star cluster in the early evening sky. Tonight The Pleiades is about a thumb width to the upper right of very bright Venus. Both are about two fists above the western horizon. Venus will be moving slightly upward with respect to the background stars each night.

Monday: Astronomers are often fascinated with large objects. Planets that could hold 1000 Earths (Jupiter). Stars that would fill up the entire inner Solar System (Betelgeuse). Galaxies with 400 billion stars (Milky Way). But what about the smallest objects? One of the smallest stars is Proxima Centauri, the closest known star other than our Sun. It is about 12% of the mass of the Sun. Earlier this year, astronomers announced the discovery of a possible third planet orbiting Proxima Centauri indicating that even very small stars can have planets. The smallest theoretically possible star would be about 7.5% of the mass of the Sun. Any smaller and it could not support the nuclear reactions characteristic of stars. For more on small stars, go to http://goo.gl/EHBdOX.

Tuesday: Mercury 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 Mercury is in the evening sky, it is east of the Sun so this occurrence is called the greatest eastern elongation. This evening will be the best evening to observe Mercury for the next few weeks. Mercury is one fist above the west-northwestern horizon at 8:30 p.m. Over the next few weeks, Mercury will move toward the Sun in the sky. By late May, it will be barely visible in the morning sky.

Wednesday: The Globe at Night April 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.

Thursday: Mars is four fists above the western horizon at 10:00 p.m.

Friday: The Lyrid meteor shower peaks next weekend. But there will be increased meteor activity in the vicinity of the constellation Lyra until then. The meteors appear to come from a point to the right of the bright bluish star Vega in the constellation Lyra the lyre. This point is about three fists above the east-northeast horizon at midnight and close to straight overhead near dawn. Go to https://earthsky.org/?p=158735 for more information.

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.