The Ellensburg, WA sky for the week of July 23, 2022

Saturday: The Southern Delta Aquarid meteor shower peaks this week and on into mid-August. Meteor showers are named after the constellation from which the meteors appear to originate. These meteors appear to come from a point in Aquarius near the star Delta Aquarii, also known as Skat. This point is about one and a half fists held upright and at arm’s length above the southeastern horizon at 1:00 am tonight. You can follow this point throughout the night, as it will remain a fist above Fomalhaut, the brightest star in that section of the sky. The Moon is approaching the new moon phase this week meaning it will not be not for many hours each night. For more information about this year’s shower, go to https://earthsky.org/?p=159138. 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.

Sunday: Uranus is either the dimmest naked-eye planet or the brightest non-naked-eye planet, depending on the darkness and quality of the surrounding sky. The vast majority of people need binoculars and a bright sky marker to find Uranus. Mars provides the bright sky marker over the next two weeks. Mars is about four fists above the southeastern horizon at 5:00 a.m. Aim your binoculars so Mars is in the far right of your field of view. Uranus will be at the far left of a typical binocular field of view. There is a star approximately the same brightness as Uranus about midway between Mars and Uranus in the sky. As the days go by, Mars will move to the lower left compared to Uranus and the background stars. Mars and Uranus will be much closer together in the sky by the weekend.

Monday: What you see with the naked eye isn’t all that can be seen. While astronomers can learn a lot from observing the sky in the visible wavelengths, many celestial objects radiate more light, and more information, in wavelengths such as radio, microwave, infrared, ultraviolet, x-ray, and gamma ray. In 2012, NASA launched the Wide-field Infrared Survey Explorer (WISE) to study objects that radiate in the infrared range such as asteroids, cool dim stars, and luminous galaxies. For an interesting comparison of how different wavelengths show different aspects of celestial objects, go to http://goo.gl/nvuax. If it weren’t for infrared telescopes such as WISE, astronomers would not know about the significant amount of dust in galaxies. We also wouldn’t know how much brighter than the Sun red supergiant stars are. Antares is a red supergiant star, currently sitting at one and a half fists above the southern horizon. In the visible wavelengths, Antares shines 10,000 times brighter than the Sun. But since Antares is much cooler than the Sun, its energy distribution peaks in the infrared. So across all wavelengths of light, Antares shines 60,000 times brighter than the Sun. The new James Webb Space telescope is also an infrared telescope.

Tuesday: At 5:00 a.m., Venus is less than a half a fist to the lower right of the waning crescent moon. 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/.

Wednesday: Zubenelgenubi, the second brightest star in the constellation Libra. The name means "southern claw", a holdover from the time when this part of the sky was associated with the neighboring constellation of Scorpius the scorpion. Zubenelgenubi is a binary star system, easily seen with binoculars as a white and yellow pair. To a person living on a planet orbiting the dimmer of the two stars, the brighter star would be nearly as bright as the full Moon appears from Earth. Zubenelgenubi is one and a half fists above due southwest at 10:30 p.m.

Thursday: Tonight the moon is new, meaning it is between the Earth and Sun. The side that is being illuminated by the Sun is facing away from us meaning we can’t see the moon and the moon is not creating light pollution. Use this time to observe the Southern Delta Aquariid meteors between midnight and dawn for the next few nights.

Friday: At 11:30 p.m., Jupiter is a half a fist above the eastern horizon and Saturn is one and a half fists above the southeastern horizon.

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.