Stellar Vista Observatory Sky Report
John Mosley
June 20 – 26
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].
This is the best week to see all the planets, plus the moon, lined up in the morning sky. Astronomy blogs are making a big deal about it and I will too. The novelty is in seeing all planets at once, including Uranus and Neptune if you have at least binoculars, but additionally, all the naked-eye classical planets are seen in the same order that they orbit the sun. And the moon passes each of them in turn. All you have to do is get up a bit early and look up.
In order from east to west, and in order of their distance from the sun, they are:
Mercury is only a few degrees high in the east-southeast 45 minutes before sunrise. There’s a narrow window of time to see it – as soon as it has risen but before the sky becomes too light. Fortunately, Mercury is quite bright. Use binoculars. You might, but probably won’t, notice the nearby fainter star Aldebaran.
Venus is brilliant and unmistakable. Use Venus to find Mercury, which is 10° from it at the 7 o’clock position.
Mars is the faintest naked-eye planet but it’s higher and so is easy to spot, three-quarters of the way from Venus to Jupiter.
Jupiter is the second brightest planet, sitting halfway up the southeastern sky.
Saturn is almost as far to the right of Jupiter as Jupiter is from Venus.
Uranus and Neptune are there too, but you’ll need a star map and binoculars or better yet a small telescope.
The planets form a line called the ecliptic because the solar system is flat and we see it edge-on. Only the moon deviates from this plane enough to matter.
The moon adds to the show! It was nearest to Saturn on Saturday, but it passes each planet in turn as it orbits the earth, moving eastward approximately 13 degrees per day. It’s 4 degrees from Jupiter on the Tuesday, 4 degrees from Mars on Wednesday, less than 4 degrees from Venus on Sunday, and 4 degrees from Mercury on June 27 (that morning the moon is such an ultra-thin crescent you probably won’t see it.) The field of view of most binoculars is 5-7 degrees, so each of these mornings you can see the moon and a planet together.
Pluto is up too, and at the same time, if you insist that it retain its status as a planet. It’s in the southwest, in eastern Sagittarius, almost 30 degrees from Saturn. But you’ll need a substantial telescope to see it.
A reminder yet again: the width of your fist at arm’s length is 10 degrees, and by far the best star charts for finding faint objects like Uranus and Neptune are planetarium apps for your smartphone and tablet computer.
Summer begins at 3:13 a.m. MDT on Tuesday. That’s the moment when the sun is as far north of the celestial equator as it will be for the year. The Farmer’s Almanac (online) has the best description of what happens then.