Mountain Skies: Mars And Mercury Flip-Flop In The Evening Sky
Last updated 6/17/2019 at 3:32pm
Mars has been slowly sinking into the evening twilight since late last year. Late last month, it was joined by Mercury, which came out from behind the sun and can now be spotted higher in the evening twilight each night. Tonight, Mercury will pass Mars and remain above the red planet until July 2. Mercury reaches it greatest elongation from the sun on June 23, after which it begins its inevitable dive back into the sunset. On the evening of July 4, the waxing crescent moon joins this pair; look for it above these two planets as you await the start of fireworks.
Jupiter is now up at sunset, so we have three visible planets in the early evening. An hour later, Saturn will join Jupiter to provide planet watchers with four bright planets to watch until Mars and Mercury set together at 11:32 p.m. Take out a pair of binoculars or a small telescope and note the four Galilean moons of Jupiter and, of course, the rings of Saturn.
Mars: As it has for months, the red planet is low in the southwest at sunset. In tandem with Mercury, it sets at 11:32 p.m.
Mercury: The elusive Mercury joins Mars low in the Western twilight, less than a degree to the North of Mars. Mercury is the brighter of the two and Mars has a reddish tint. As the nights progress, these two planets will separate. Mercury starts its dive into the sunset in late July and will pass by the sun in inferior conjunction on July 21.
Jupiter: Jupiter is now rising before sunset and, thus, is low in the southwest as the sky darkens. Until the moon rises at 9:15 p.m., Jupiter is the brightest object in the sky, i.e., now our “evening star.”
Saturn: Rising at 10:10 p.m., roughly two hours after Jupiter, Saturn is low in the southeast in the hindquarters of Sagittarius, the archer. We find Saturn on this centaur’s hindquarters east of the famous teapot.
Venus: Venus rises at 5:18 a.m., not quite an hour before sunrise. However, since Venus is the brightest object in the nighttime sky after the moon, it can still be spotted low in the morning twilight. It will be there until it dives into the twilight next month. Sunrise is at 6:16 a.m.
In the last column we described Boötes, the herdsman or bear driver, perhaps better visualized as a kite. Boötes, with the bright “ginger-colored” star Arcturus being most prominent, is high in the south on a June evening an hour or two after sunset. Now, look to the east of the herdsman for an almost complete circle of moderately bright stars that marks the location of Corona Borealis, the Northern Crown. Then, to the east of the crown, a pattern of six stars forms a great letter “H” in the sky. Appropriately, this is the constellation of Hercules, known as Heracles to the Greeks. One cannot study Greek mythology without hearing of the labors of Hercules and many of these stories are illustrated among the constellations in the sky.
Hercules is pictured upside down as we view him from the northern hemisphere. Thus, the lower two stars in the letter “H” mark his shoulders, the middle two his waist, and the upper two his legs. In some ways, the constellation is similar to that of Orion, the hunter, but by no means as obvious. Perhaps of most interest is the Great Cluster in Hercules, known to stargazers as Messier 13 (M13). It can be spotted with a pair of binoculars or a small telescope on the upper Western leg of the letter “H.”
At 11:54 a.m. EDT Thursday, we have the summer solstice, which marks the first moment of summer in the northern hemisphere. This is the point in the Earth’s orbit when the northern hemisphere reaches its maximum tilt towards the sun. Thus, the sun is highest in the sky at noon and the days are longest. In Brevard, sunrise will occur at 6:17 a.m. EDT and sunset at 8:49 p.m. that evening. This will give us 14 hours 32 minutes of daytime. Happy Solstice!
June 17, 4:31 a.m. EDT - Full moon.
June 18, 10 a.m. EDT - Mercury 0.2° North of Mars. Low in the west after sunset.
June 18, midnight EDT - Saturn 0.4° North of the moon.
June 20 - The sun appears to move from Taurus the bull into Gemini the twins.
June 21, 11:54 a.m. EDT - Summer Solstice. Summer begins! Longest day of the year.
June 25, 5:46 a.m. EDT – Last quarter moon.
(The Learning Center at PARI is a public not-for-profit 501 (c) (3) organization established in 1998. Located in the Pisgah National Forest, the Learning Center provides STEM educational programs at all levels, from K-12 through post-graduate research. For more information about the Learning Center at PARI and its programs, visit http://www.pari.edu.)