"Tonight's Sky" is written by retired planetarium director Dave Leake and reprinted with his permission. See Dave Leake's Prairie Skies column in the Champaign–Urbana News-Gazette each Sunday. Dave Leake's preview of 2020 sky events can be found here.
June 28 – July 4
If you can stay up past 11 p.m. this week, look to the southeast where both Jupiter and Saturn reside. Jupiter is on the right and the brighter of the two. To Jupiter’s right is the Teapot of Sagittarius. Sagittarius is a “constellation” and on an official list of 88 star groupings recognized globally. The Teapot is an “asterism” which means it’s not on the official list but, hey, it looks like a teapot! The Big Dipper is another asterism. The Milky Way appears in the south near the teapot as it if were steam emanating from the spout. If you’re in a dark sky, use binoculars and look just above the spout of our teapot for the Lagoon Nebula.
Tonight, a nearly Full Moon rises in the southeast just after sunset, making a nice triangle with Jupiter and Saturn. Jupiter will be the brighter of the two star-like objects. The familiar Big Dipper is in the northwest, appearing to pour out on the land below. Near straight up as the Sun sets and east of the bright star Vega, is the fainter constellation of Hercules. Don’t look for an upside-down hero perched on one knee but see if you can find four stars making a keystone shape. Set the alarm for 4 a.m. Saturday morning and look low in the east for the brilliant planet Venus. Binoculars will show Venus appearing less than a degree from the star Aldebaran.
Tuesday is Jupiter’s “opposition” date, meaning that it is situated opposite the Sun from our Earth. Watch it rise in the southeast as the Sun sets. This is also a time when Jupiter is closest to Earth and bright! Use binoculars to look for its moons. For the Pluto fans out there, Wednesday is Pluto’s opposition. Even though Pluto is also at its “brightest”, it still requires a 12-inch telescope or larger. You can still point it out to your friends though as it’s located between Jupiter and Saturn. If you saw Venus and the star Aldebaran close last week, this coming Friday morning, the planet and star have separated, and they are joined by a lovely crescent Moon.
Tomorrow is Saturn’s opposition date, a day when it’s closest to Earth. By “close”, we mean about 836 million miles from us! The rings extend to about 75,000 miles on either side of the planet but average only 60-feet thick! And you can see them in a small telescope! Look for it left of Jupiter in the southeast. If all goes well, NASA will launch the Mars 2020 rover, now known as Perseverance, on Wednesday morning (8:35 a.m. CDT). It’ll take just under 7 months to make that trip. Mars rises due east at midnight. It’s currently brightening ahead of a great view this October. Start looking for the crescent Moon in the west about the middle of this week.
July 26 – August 1
Look south all this week just after sundown for the reddish star Antares, the heart of the celestial scorpion. To the upper right are three stars making nearly a vertical line. This is the head of Scorpius. Venture further to the right and you’ll find two more stars, further apart. Officially, these two stars are part of Libra, the Scales. The top star is Zubeneschamali and the lower one is Zubenelgenubi. The star names refer to the northern and southern claw. While measuring scales don’t have claws, scorpions do! These stars used to be part of the scorpion. In ancient times, the Sun was in this spot in the sky during the autumn equinox, when day and night were “balanced”.