In mid-northern latitudes, May is one of the best months for sky watching. While the sun continues to set later throughout the month amid warming temperatures, cool, clearing breezes blow from the northwest revealing a transparent sky. Enjoy the season.
Jupiter is the first of the three bright outer planets to reach opposition in a span of 79 days.
For more about Jupiter and the bright evening planets, see these articles:
- 2018: Five Planets Visible at Once
- 2018, Summer: Evening Planet Parade: Five Bright Planets Visible During One Evening
- 2018: Venus the Evening Star
- 2017-2019: Mars Observing Year with a Perihelic Opposition, July 27, 2018
- 2018: Mars Perihelic Opposition
- 2017-2018: Jupiter’s Year in the Claws of the Scorpion, A Triple Conjunction
- 2018: Three Planets at Opposition in 79 days
- 2018: Saturn with the Teapot
Bright Jupiter enters the early evening sky at its opposition on May 8. It is 3.2° from Zubenelgenubi. Jupiter is retrograding and passes the star on June 3. After the planet resumes direct motion, Jupiter passes the star again on August 15. Jupiter ends the month, just 1° from Zubenelgenubi. On the chart above, Jupiter gleams in the southeastern sky at 10:30 p.m. CDT on opposition night.
May opens with brilliant Jupiter shining in the west after sunset.
The waxing gibbous moon moon (16.1 days old) is 18° to the left of Jupiter. The planet rises at 8:17 p.m. CDT (in Chicago), 18 minutes after sunset.
As the month ends, the moon passes into Jupiter’s field again. The chart above shows the view in the south at 10:50 p.m. CDT. Here are the highlights:
- May 25: The waxing gibbous moon (10.7 days old) is 6.3° above the star Spica.
- May 26: The waxing gibbous moon (11.6 days old) appears farther east this evening. It is 9.3° to the right of Jupiter.
- May 27: The nearly full moon (12.6 days old), yet still waxing gibbous is 5.1° to the left of Jupiter.
- May 28: The full moon is 17.5° to the left of Jupiter and 10.9° above Antares.
As the month closes Jupiter shines brightly in the southeast at sunset.