This Week’s Sky at a Glance, 2025 June 21 – June 28
This Week’s Sky at a Glance, 2025 June 21 – June 28
With the Milky Way becoming prominent on summer evenings, binocular stargazing is a great way to pass the time. From Cygnus heading south the Milky Way is split by the Great Rift, a region where the starlight between us and the centre of our galaxy is blocked by vast dust clouds. The western side of the Milky Way runs through parts of Lyra and Ophiuchus to Scorpius, and the eastern side runs through Aquila and Scutum to Sagittarius.
A good place to start observing is with orange Antares in Scorpius. Check out the colour of this supergiant star, and pick out the globular cluster M4 in the same field of view to its right. East of Scorpius is the Teapot asterism that makes up much of Sagittarius the Archer. If you extend the two stars at the top of the Teapot’s spout to the right you will find M6, the aptly named Butterfly Cluster. To its lower left is a large star cluster called M7 or Ptolemy’s Cluster. To the right of M7 is a pair of bright stars, Shaula and Lesath, which marks the stinger of Scorpius. They have been nicknamed the Cat’s Eyes.
About a binocular-field width above the Teapot’s spout you will find a fuzzy patch with a small cluster of stars in or near it. The fuzzy patch is a cloud of dust and gas called M8, the Lagoon Nebula, where stars are forming. Radiation from hot young stars makes the gas glow, and it can be seen with the naked eye in rural areas. A telescope will reveal dark dust lanes in the nebula that suggest its lagoon name. The cluster of stars is called NGC 6530, where NGC stands for New General Catalogue. Just above M8 is a smaller cloud, M20 or the Trifid Nebula, and the nearby star cluster M21.
This Week in the Solar System
Saturday’s sunrise is at 5:36 and sunset will occur at 9:15, giving 15 hours, 39 minutes of daylight. Next Saturday the Sun will rise at 5:38 and set at 9:16, giving 15 hours, 38 minutes of daylight.
The Moon is near Venus this Sunday morning and close to the Pleiades on Monday. It reaches the new phase Wednesday and it is a binocular field to the right of Mercury in Thursday evening twilight. Mercury sets an hour and a half after sunset all week but it is dimming rapidly. Mars remains within a binocular view of Regulus for a few days before pulling away to the east. Saturn rises around 1:30 am this weekend, with Neptune being half a binocular field above it. Jupiter is in conjunction on Tuesday, moving to the morning sky in mid-July.
Tune in to the Sunday Night Astronomy Show at 8 pm on the YouTube channel and Facebook page of Astronomy by the Bay.