Sunday, July 25
The Moon passes 4° south of Jupiter at 9 P.M. EDT. Two hours later, the pair has cleared the horizon, with magnitude –2.8 Jupiter now nearly 4.8° northwest of the Moon. Both lie in Aquarius and will continue to rise overnight — the best time to view them.
The largest planet in the solar system, Jupiter currently sits about 380 million miles (613 million kilometers) from Earth. From that distance, its disk spans 48". Late tonight, the four Galilean moons are arrayed around it with two on either side: Io (closer) and Callisto to the east and Europa (closer) and Ganymede to the west.
If you follow Jupiter into the early hours of July 26, you’ll see Io’s shadow cross onto the disk around 3:10 A.M. EDT, followed by the moon itself roughly 35 minutes later.
Sunrise: 5:53 A.M.
Sunset: 8:20 P.M.
Moonrise: 9:56 P.M.
Moonset: 7:20 A.M.
Moon Phase: Waning gibbous (97%)
Monday, July 26
After dark, turn your gaze just south of easy-to-recognize Cygnus the Swan, already flying high in the east. There you’ll find Vulpecula the Fox, a relatively small constellation that is home to the beautiful and often underappreciated open cluster NGC 6940.
The 0.4°-wide cluster is just over 6° southwest of magnitude 2.5 Epsilon (ϵ) Cygni. This young gaggle of suns shines around magnitude 6 and shows up well with binoculars or any small scope even under moderate light pollution, so the Moon shouldn’t interfere too badly.
While you’re in the area, make sure to stop over at Albireo, the 3rd-magnitude star that marks Cygnus’ head and beak. Although a single point of light to the naked eye, Albireo is relatively easy to split with larger binoculars or a small scope. Its components offer a stunning color contrast: one is bright blue, while the other appears deep yellow-orange. This double is one of the crown jewels of the sky’s colorful pairs, and not to be missed.
Sunrise: 5:53 A.M.
Sunset: 8:19 P.M.
Moonrise: 10:25 P.M.
Moonset: 8:30 A.M.
Moon Phase: Waning gibbous (91%)
Tuesday, July 27
Continuing its trek past the giant planets this week, the Moon passes 4° south of Neptune at 2 P.M. EDT. The best time to catch this pair, however, is in the early morning hours just after midnight on the 26th. They hang together in eastern Aquarius, with Neptune about 8° below the Circlet in Pisces.
By 4 A.M. EDT, the bright Moon lies 8.5° southwest of Neptune, which is a dim, flat, magnitude 7.7 “star” in binoculars or a telescope. Our satellite’s bright light will wash out much of the background sky, making the planet a bit harder to find. Jupiter, which sits nearly 16.5° due west of the Moon at that time and appears even with it above the horizon, will be much easier to pick out, still at magnitude –2.8.
Sunrise: 5:54 A.M.
Sunset: 8:18 P.M.
Moonrise: 10:52 P.M.
Moonset: 9:38 A.M.
Moon Phase: Waning gibbous (85%)
Wednesday, July 28
Visible above the horizon by sunset this evening is the constellation Virgo the Maiden. This month, she plays host to asteroid 4 Vesta, which tonight sits less than 1° southeast of M61, a spiral galaxy in the southern region of the massive Virgo Cluster. Vesta is two magnitudes brighter at magnitude 7.4, while M61 glows a fainter magnitude 9.7. Then again, although Vesta is a mere 326 miles (525 km) across, it lies just 240 million miles (389 million km) away. M61 is roughly 100,000 light-years across, but sits some 60 million light-years distant.
Vesta will be easy to spot with a telescope even under suburban skies, while M61 may take a bit more searching. You’ll likely be able to find the pair with binoculars from a darker site, although the Moon’s light creates natural light pollution that will up the challenge. Make sure to start searching as soon as it gets dark, as Virgo is already setting once the Sun disappears and your view will be gone shortly before midnight.
Vesta will continue southeast through Virgo, skimming close to NGC 4457 — a lenticular galaxy also in the Virgo Cluster — at the end of the month.
Sunrise: 5:55 A.M.
Sunset: 8:17 P.M.
Moonrise: 11:16 P.M.
Moonset: 10:41 A.M.
Moon Phase: Waning gibbous (77%)