Stellar Vista Observatory Sky Report
John Mosley
June 27 – July 3
The Sky Report is presented as a public service by the Stellar Vista Observatory, a nonprofit organization based in Kanab, Utah, which provides opportunities for people to observe, appreciate, and comprehend our starry night sky. Additional information is at www.stellarvistaobservatory.org. Send questions and comments to [email protected].
How soon after sunset can you see stars with your eyes alone? Here’s a self-test to perform one evening: how soon can you see the star Arcturus after sunset? I picked Arcturus because it’s bright and nearly overhead. Find Arcturus one evening as the sky is growing dark approximately a half-hour after sunset and mentally mark its position in the sky, perhaps in reference to trees and buildings.
The next night look for it in that same position 15 or 20 minutes after sunset. It’s hard to focus your eyes on something at an infinite distance that you cannot see, but you can do it. I was able to see Arcturus only 18 minutes after sunset. You can find the precise time of sunset for your exact location on the web in lots of places; start with the Old Farmer’s Almanac.
The moon is new on Tuesday. Here’s another self-test: how soon after the moon is new can you actually see it as an ultra-thin crescent? The precise time of the new moon is 11:55 a.m. MDT. At sunset that night the moon will have an “age” of nine hours, and the moon has never been seen so early in the lunar month.
The next night at sunset the moon will have an “age” of 33 hours, and it’s definitely possible to see so “new” a moon. You’ll need a sky clear from haze, a flat northwest horizon and to look within a few minutes of a half-hour after sunset. The sky will still be very bright and the moon will be only a few degrees high, so it will be a challenge. Use binoculars and compliment yourself if you’re successful.
By Saturday, the moon is not only easy to see, it’s pretty, and it’s 6 degrees to the right of the star Regulus in Leo.
All the planets are in the morning sky where they span 112 degrees or almost a third of the sky. In order from east to west they are Mercury, Venus, Mars, Jupiter and Saturn. Mercury is by far the hardest to see because it’s so near the sun and rises in morning twilight. Venus rises two hours before the sun and is brilliant. Jupiter is almost as bright while Mars and Saturn rival the brightest stars.
Comet C/2017 K2 is inbound on its first-ever visit to the inner solar system. It will be within the range of any telescope but probably not binoculars in the southeast in the early evening sky. I’ve been tracking it, and although hopes were high for it to brighten substantially it’s running slightly fainter than predicted.
It passes closest to earth on July 14 but should be visible all July and August. It’s in the constellation Ophiuchus, the Serpent Bearer or Healer, where it was 9th magnitude in mid-June. You can generate a finding chart at https://theskylive.com, but best is a planetarium app like SkySafari (my favorite). It remains in Ophiuchus until Aug. 3.