Scorpius and Sagittarius highlight July nights, scooting low across the south. Antares highlights the scorpion’s hook-shaped body, with teapot-shaped Sagittarius to its left. Under dark skies, the Milky Way rises from the teapot’s spout like steam. Meanwhile, the Big Dipper stands high in the north and northwest during the evening, with its handle to the upper left and bowl to the lower right.
The full Moon of July is known as the Hay Moon, Thunder Moon, or Apollo Moon.
Perigee July 13
Apogee July 25
Moon phases are Central Time.
Capricornus, the sea-goat, is low in the southern sky as darkness falls at this time of year. Its brightest stars form a wide triangle. None of the sea-goat’s stars is especially bright, though, so you need a fairly dark sky to make them out.
The Moon is at its last-quarter phase at 7:25 a.m. CDT, so sunlight illuminates half of the lunar hemisphere that faces Earth. The illuminated portion of that hemisphere will grow smaller each day until the Moon is new on October 19.
Asteroid 2012 TC4 will pass about 30,000 miles from Earth tonight. Astronomers are tracking it to learn about the asteroid and its orbit. 2012 TC4 is about the size of a house, which is smaller than the asteroid that exploded over Russia in 2013.
Rho Cassiopeia, one of the largest stars in the galaxy, stands to the right of the “W” outlined by Cassiopeia, which is in the northeast at nightfall. The star, which is visible to the unaided eye, eventually will blast itself apart as a supernova.
As twilight fades away this evening, the stars slowly fade in. The first stars to pop into view include yellow-orange Arcturus, fairly low in the west; ruddy Antares, quite low in the southwest, and the three stars of the Summer Triangle high overhead.
Bright orange Aldebaran, the eye of the celestial bull, stands to the lower left of the Moon as they rise late this evening, and even closer to the upper left of the Moon at first light tomorrow.
Fomalhaut, the leading light of Piscis Austrinus, the southern fish, stands low in the southeast at nightfall, and at its highest, due south, a few hours later. It’s bright, and there are no other bright stars around it, so it stands out.
The Moon is just past full but it still looks round and bright, and is visible almost all night. The full Moon looks unusually large just after it rises. Known as the Moon Illusion, this is not a physical effect, it’s simply an optical illusion.
The Harvest Moon is on display tonight. It is the full Moon closest to the autumnal equinox, which took place September 22. September’s full Moon occurred about 16 days before the equinox, with October’s full Moon about 13 days after the equinox.
Venus shines as the brilliant “morning star,” low in the east at first light tomorrow, with Mars quite close to the lower right. Mars is only about one percent as bright as Venus, but its proximity to the brighter world will help you pick it out.
