Stellar Vista Observatory Sky Report

John Mosley

March 6 – 12

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 John@StargazingAdventures.org.

The last two weeks were exciting because of the series of great conjunctions, but they’re over, and the best we’ll see for months to come are moderately close conjunctions when the moon passes Venus and Mars, as it must do once a month. None of these will be close enough to write home about (although I’ll write about them here).

That said, let’s begin with the three bright planets that are out this evening, as I always do.

By far the brightest planet is Venus, in the west from twilight until it sets 2½ hours after the sun. Venus is so brilliant because it is close (for a planet, half as far again as the sun) and its clouds are highly reflective.

Venus is in the constellation Pisces, which has no bright stars of its own, but it does have Jupiter, directly below. When Jupiter is in the sky by itself it’s the brightest object, but it can’t compete with Venus. Even though it’s much larger than Venus, it’s less reflective and four times more distant so it’s only one-sixth as bright.

As this week opens Jupiter is 5° below Venus and the two form a very pretty pair, especially during late twilight if thin clouds lend a bit of color. They’ll fit in the field-of-view of any binoculars, and with binoculars you’ll also see Jupiter’s Galilean moons strung in a line.

Now watch how quickly Venus leaves Jupiter behind. Recall that Venus passed only ½° from Jupiter on March 1. On the 6^th they’re 5° apart and on the 12^th they’re 11° apart. Which is moving? (Answer yourself before reading on.)

Jupiter is so distant and orbits the sun so slowly that it is relatively motionless against the background stars. Venus is closer and, feeling the sun’s gravity more strongly, orbits the sun more quickly in terms of mph, so their increasing separation is due almost entirely to the motion of Venus.

Watch them continue to separate in weeks ahead – but not for too many weeks. Jupiter sets four minutes earlier each day and soon we’ll lose it as it slips behind the sun just as a few weeks ago we lost Saturn to the same process.

Tonight’s third planet (and the faintest) is Mars, which from the latitude of southern Utah is due south and nearly overhead as darkness falls. Mars is in Taurus where it forms a nearly perfect equilateral triangle with two other stars that rival it in both brightness and color. These are Betelgeuse, in Orion, below Mars and a bit to the left, and Aldebaran, in Taurus, to Mars’ lower right. Which of the three is brighter? Which is redder? Train your eyes to notice subtle differences by looking long, carefully, and thoughtfully. There’s much to see if you take the time to look.

The sky’s third bright red star, by the way, is Antares in Scorpius, and it’s on the opposite side of the sky.

Stellar Vista Observatory provides portable telescopes and tripod mounted binocular kits on loan for free to residents and visitors in Kane County. Enhance your enjoyment of the night sky! To learn more, request a loan, or attend one of SVO’s free public star parties for 2023, visit https://stellarvistaobservatory.org/ or drop in to the Kane County Office of Tourism.