SOUTHERN UTAH — The weekly Sky Report alerts people to what they can see in the night sky by simply stepping outdoors and looking up, perhaps only with a pair of binoculars.
The Sky Report is presented as a public service by the Stellar Vista Observatory, a nonprofit organization based in Kanab, which provides observational experiences for people to enjoy, appreciate and comprehend what we can see in our starry night skies.
Witness Mercury
Last month we watched Venus disappear from the evening sky, to be replaced briefly by little Mercury. Mercury is a poor substitute, being both fainter and closer to the horizon, and whereas Venus dominated the early evening sky it’s a challenge to even see Mercury and most people never have. This is your chance.
Mercury is the closest planet to the sun so it never strays far from the sun and you can see it only just before sunrise or just after sunset, and then only in twilight. First, you’ll need a low western horizon that is not blocked by hills or anything else, so perhaps find a high vantage point. Look for Mercury in the west-northwest at about 9:20 or so, long before the sky is very dark, when it is only about 10° or so high, above the true geometric horizon. The width of your fist held at arm’s length is about 10°, so Mercury is definitely very low – and that’s the trick.
Mercury is as bright as the brighter stars, but it looks like just one of the stars, so it helps to know which it is and which are nearby stars, and the diagram below will help. Definitely use binoculars if you have them, and if you don’t – get a pair. You will find serviceable 7X50 binoculars at sporting goods stores and online for under $50.
Meanwhile the planet Venus is moving from the evening sky, to the left of the sun, to the morning sky, to the right of the sun, and it’s between the earth and sun on the third. We’ll see it in the morning sky later this month; stay tuned.
Jupiter, Saturn & Mars
Elsewhere the moon brightens the night sky and makes the dimmer stars and the Milky Way invisible. On the 1st the star just below the moon is Spica, the brightest star in Virgo, and on the fourth below the moon is Antares, the heart of Scorpius, the Scorpion. And on the seventh the moon is to the right of the bright planet Jupiter … which takes us to the next three planets visible tonight: Jupiter, Saturn and Mars.
Jupiter and Saturn theoretically rise by midnight, but the time you’ll actually see them depends on the height of whatever blocks your horizon.
Jupiter is considerably brighter than any star and it shines with an unblinking white light, so you can’t miss it, low in the southeast during the hours after midnight. Saturn is immediately to the left of Jupiter, and although Saturn is only 1/16 as bright as Jupiter, that’s still as bright as the brightest stars. These two giant planets will remain close all this year and next.
Mars trails the two giants, rising at 2 a.m., and it has a slightly orange color. The best time to see them is around 4-5 a.m. when they’re a third of the way up the southern sky. Jupiter is in Sagittarius, Saturn is in Capricornus, and Mars is in Aquarius – constellations of the summer sky.
The weekly Sky Report is written by John Mosley, a retired astronomer who lives in Ivins and who serves on the advisory committee for Stellar Vista Observatory. Send questions and comments to [email protected].