Thursday, April 17, 2025

The Ellensburg, WA sky for the week of April 19, 2025

Saturday: This week is International Dark Sky Week. Lights that are aimed upwards or not properly capped 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. Learn about how you can help at https://idsw.darksky.org/

Sunday: The first day of spring was March 20. The most recent full moon was April 12. That means today is Easter. The standard way to figure out 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 two fists above due southeast horizon at 9:00 p.m. For an algorithm on how to calculate the exact date of Easter for any year, go to https://www.rmg.co.uk/stories/topics/when-easter

Monday: Mercury will be as far away from the Sun in the sky as it will get this half of its orbital cycle. This "farthest away" point is known as the planet's greatest elongation. Since Mercury is in the morning sky, it is west of the Sun and this occurrence is called the greatest western elongation. Often, the day of greatest elongation is a good time to observe Mercury. But not this cycle. Mercury is just barely above due east at 5:30 a.m. You are much more likely to see the bright planet Venus, nearly a fist held upright and at arm’s length above the eastern horizon. You should be able to see Mercury with binoculars. Saturn may also be visible with binoculars, about halfway between Venus and the horizon. Over the next few weeks, Mercury will move toward the Sun in the sky. By mid June, it will be visible in the evening sky.

The Lyrid meteor shower peaks tonight. 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. The best time to see the shower this year is between 11:00 p.m. and moonrise at 4:00 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.

Tuesday: Jupiter is nearly three fists above due west at 9:00 p.m. Mars is nearly six fists above the southwestern horizon at this time.

Wednesday: Sirius, the brightest star in the night sky, is getting lower and lower. It is one fist above the southwestern horizon at 9:00 p.m. By mid-May, it will be lost in the glare of the setting Sun.

Thursday: On Monday I described Venus as “the bright planet Venus”. This morning, it is at its brightest for this orbital cycle. Its visual magnitude is -4.54. By comparison, Jupiter, the second brightest point of light in the sky, is magnitude -2, only about one tenth as bright. Venus is about a fist above the eastern horizon at 5:30 a.m.

Friday: As the rock group Journey once thought of singing, “Wheel in the sky keeps on turnin’. I know where the Dipper’ll be tomorrow.” Every night, the Big Dipper and Cassiopeia make a wheel in the sky that turns around the North Star in a counterclockwise direction. Every year on April 24 at 10:00 p.m., the Big Dipper is straight overhead and W-shaped Cassiopeia is low on the northern horizon. Every year on April 25 at 10:00 p.m., the Big Dipper is straight overhead and W-shaped Cassiopeia is low on the northern horizon. Every year on April 26 at 10:00 p.m., the Big Dipper is straight overhead and W-shaped Cassiopeia is low on the northern horizon. Oh, am I boring you? Of course, there are subtle charges in the position from night to night. Each northern constellation moves about one degree counterclockwise from one night to the next. But this is not going to change their position in the sky drastically over a few days. So, if you know where the Big Dipper is tonight, you DO know where it’ll be tomorrow. If you are really struggling to understand this concept, Don’t Stop Believin’ in yourself. Just keep studying Faithfully.

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.

No comments: