Astronomy: The Week Ahead – Mon 25 May to Sat 30 May

Sky at night


Monday May 25

The First Quarter Moon occurs at 10:20 A.M. today, and tonight you will see it along with Jupiter and Venus in the west, as the sky darkens. They are about equally spaced, in three zodiacal constellations. Name the constellations! Bonus points, name the bright stars obvious in two of the constellations.


Tuesday May 26

The winter Milky Way is more subtle than its summer counterpart. Look northeast while the sky is still dark before sunrise and you’ll find it glowing in Perseus and Cassiopeia. The summer Milky Way is almost directly overhead, starting in Cygnus, which is at zenith (straight up) this morning.


Wednesday May 27

Tonight’s waxing gibbous moon is 9-1/2 days old and 73% illuminated, due south and passing now through Virgo. The bright star Spica is likely the only star you’ll see in the area, as the moon’s brightness washes out anything dimmer nearby. Saturn is moving back into the recognizable reaches of Libra, low in the southeast. This view is an hour after sunset.


Thursday May 28

Look to the east this morning before the sky brightens, and see if you can recognize these star patterns. There are two well-known asterisms, in two constellations. An asterism is a recognizable pattern of stars that do not make up an entire constellation.


Friday May 29

Nice show in the west as sunset deepens tonight. Jupiter is up in Cancer, and Venus in Gemini is in the same binocular or telescope field of view as the magnitude 3.5 star Kappa Geminorum, one half degree up to the planet’s right. Venus is at a brilliant magnitude 4.25. Look at them together to see what a 7+ magnitude difference is like.

Turn southeast also, to see a bright waxing gibbous moon close to Vega’s bright star Spica, and Saturn low near the horizon. So much to see!


Saturday May 30

M10 and M12 are the two largest and brightest globular clusters in the constellation Ophiuchus, the snake bearer. Ophiuchus is the richest constellation for globular clusters. This pair are also close to each other in our sky, and easy binocular targets. M10 is 20 arcseconds in diameter and nearly naked eye at magnitude 6.4. It is one of the closer objects of this type at 14,000 light years. M12 is a bit dimmer, magnitude 7.6, and smaller at 16 arcseconds. Look back and forth at them, see if you can discern their differences. M12 is nearly the same distance, at 15.700 light years away.

Happy viewing!