"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.
Set an alarm for tomorrow morning to check out Jupiter and Venus in the morning sky. Look close to the horizon, just right of east at 5am. The two planets appeared closest last Friday but you can now watch them slowly separate throughout the week. Venus is the brighter of the two.
Monday night, see if you can find Mercury to the lower right of the Moon just after sunset in the west-northwest. The weekend brings us the Eta Aquarid meteor shower.
Dr. Decker French gives a talk on galaxies at the planetarium Friday at 6:30pm and the CU Astronomical Society has a free public open house at their observatory Saturday evening starting at 8pm, weather permitting (cuas.org).
Tomorrow night, the Moon sits just above the star Regulus, the heart of Leo, the Lion. By Friday, the Moon is farther east, situated above and left of the bluish star Spica.
In the early morning sky, our four planets are spacing themselves out. If you look at 5am, Venus is the brightest and closest to the horizon, due east. Then in a line extending to the upper right, you have Jupiter, Mars, then Saturn. Keep watching each morning as Jupiter seems to approach Mars, the two being closest towards the end of the month. Compared to the horizon, Jupiter seems to be moving quickly to the west but, in actuality, Mars is moving eastward faster with respect to the background stars.
Tonight we experience the first prime time total lunar eclipse since 2015. A lunar eclipse occurs when the full Moon passes through the Earth’s shadow so it looks like something is taking a bite out of the Moon. Since the Moon’s orbit is off five degrees, it usually passes above or below the shadow. The event begins at 9:28pm and the Moon is completely in the shadow at 10:29pm. The Moon begins to emerge from the shadow at 11:54pm and we have a full Moon again by 12:55am. If skies are clear, the CU Astro Society will have telescopes available to view the eclipse set-up in the Staerkel Planetarium circle drive. Park in the M-1 lot and watch with us.
The action this week is back in the morning sky as the waning Moon glides by all of our morning planets as it moves eastward each day in its orbit. Look at about 4:30am, low in the eastern sky. Tuesday morning, a crescent Moon is to the lower right of Jupiter and Mars. The next morning it is to the lower left of these two planets. Friday morning a very thin Moon is to the lower left of brilliant Venus. Sunday morning the Moon is out of the picture, but Jupiter and Mars appear to be at their closest at a half degree separation. Jupiter is 15 times brighter than Mars and 3.5 times farther away from us.
May 29–June 4
Tomorrow’s New Moon means we’ll see a lovely crescent Moon in the evening sky later in the week. Thursday evening, the Moon is in the northwest beneath the two stars marking the heads of the Gemini Twins. The bright star to the far right is Capella and the one to the lower left is Procyon, the Little Dog Star. We say goodbye to these “winter stars” as our spring stars take center stage.
The Big Dipper is nearly straight up at sunset with the backwards question mark shape of Leo the Lion far below the bowl. Follow the curve of the dippers handle to the orange star Arcturus, the second brightest star we can see in our sky.