The Sky Today on Tuesday, September 1: Visit globular cluster M30

Located in Capricornus, this compact, bright globular is a great target to try for during the moonless window tonight. | Published: September 1, 2026 Looking for a sky event this week? Check out our full Sky This Week column. August 31: Venus and Spica gather close There’s a short dark window early in the evening after sunset and before moonrise to do a little deep-sky observing. Let’s try for M30, the brightest deep-sky object in Capricornus; it’s also the Sea Goat’s sole Messier object. M30 is a globular cluster that shines at magnitude 7.2. It’s just 12’ across, quite compact. That small size, coupled with its highly concentrated stars, makes it relatively easy to spot in binoculars or any small telescope. You’ll find it just over 3° east-southeast of magnitude 3.7 Zeta (ζ) Capricorni, close to a 5th-magnitude background star. Around 9 P.M. local daylight time, it stands 15° above the southeastern horizon. As always, the higher your magnification, the more detail — and stars — you’ll see, particularly in the crowded center of this cluster. That center is less than 10” across, roughly a light-year in physical length. Overall, the cluster exerts gravitational influence over stars up to some 140 light-years away. M30 has an estimated age of roughly 13 billion years, and lies at a distance of nearly 28,000 light-years from Earth. Sunrise: 6:28 A.M.Sunset: 7:32 P.M.Moonrise: 9:32 P.M.Moonset: 11:21 A.M.Moon Phase: Waning gibbous (74%)*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location. Alison Klesman is senior editor of Astronomy magazine. She holds a Ph.D. in astronomy and has studied a variety of topics, from minor planets to supermassive black holes.