Topline
Since its celestial “kiss” with Venus in June, Jupiter has been slowly sinking towards the sun as seen from Earth. Skywatchers now have only a few evenings left to see the solar system’s largest planet before it slips into the sun’s glare. This Thursday and Friday, July 9 and 10, the planet will sit very low in the west-northwest about an hour after sunset. Here’s how to see Jupiter in the evening sky for the last time until November.
Key Facts
Jupiter will set about 45 minutes after the sun this week. Observers will need a clear, flat western horizon and binoculars to find it, though once found it should be visible to the naked eye. It will be below and to the right of bright Venus.
Jupiter is disappearing from the evening sky because it is moving toward conjunction with the sun, as seen from Earth. That will occur on July 29. Jupiter will then emerge into the morning sky in mid-August.
Jupiter will next be seen in the post-sunset sky in November, when it becomes visible in the east very close to Mars.
The next Venus-Jupiter conjunction will take place on Aug. 26, 2027. According to Universe Today, Venus will occult Jupiter on Nov. 22, 2065, the only such event of the 21st century.
How To See Jupiter Before It Vanishes
Seeing Jupiter before it vanishes won’t be easy. Jupiter will be bright, shining at about magnitude –1.6, but it will set during twilight when low in the west-northwest sky on Thursday and Friday, July 9 and 10. Look above the west-northwestern horizon about 45 minutes after sunset, preferably with any pair of binoculars. With the latter, observers can sometimes see some of Jupiter’s four large Galilean moons — Io, Europa, Ganymede and Callisto. A small telescope reveals its cloud belts and, under good conditions, the Great Red Spot, a vast storm that has been going on for almost 200 years.
Stargazing This Weekend
This weekend is a busy one for skywatchers. First comes a lovely glimpse of Mars. Look low toward the east-northeast an hour before sunrise on Saturday, July 11, for a 13%-lit waning crescent moon close to Mars and Aldebaran in the constellation Taurus, with the Pleiades open cluster of stars nearby. Also on Saturday, July 11 and Sunday, July 12, Manhattanhenge occurs at sunset in New York City, with the sun aligning with the street grid. Saturday sees the full sun alignment at 8:20 p.m. EDT, with the half sun alignment on Sunday at 8:21 p.m. EDT. On July 14, the new moon brings the darkest skies of the month, just in time for the beginning of the annual Perseid meteor shower on July 17. On that date, a crescent moon appears near Venus after sunset, while on July 29, the full Buck Moon rises at sunset.
Background
Jupiter is the fifth planet from the sun and the largest planet in the solar system, with more than twice the mass of all the other planets combined. It rotates very quickly, with one day on Jupiter lasting only 10 hours, the shortest in the solar system. NASA’s Juno spacecraft has been orbiting Jupiter since 2016, but two spacecraft are on their way to study its moons. NASA’s Europa Clipper mission is traveling toward the Jupiter system and is scheduled to arrive in 2030 to investigate whether Europa may have conditions suitable for life. Meanwhile, the European Space Agency’s JUICE mission will arrive in 2031 to fly by Callisto and Europa, eventually becoming the first spacecraft to orbit a moon other than Earth’s when it arrives at Ganymede for a nine-month mission finale.