Each Monday I pick out the northern hemisphere’s celestial highlights (mid-northern latitudes) for the week ahead, but be sure to check my main feed for more in-depth articles on stargazing, astronomy, eclipses and more.
The Night Sky This Week: October 23-29, 2023
In a hangover from the recent “ring of fire” annular solar eclipse, the moon is still in the correct position to align with the sun and Earth. That means another eclipse—this time on the other side of Earth—as the full “Hunter’s Moon” crosses into Earth’s shadow. However, it’s a very slight lunar eclipse and visually this won’t be anywhere near as big a deal. Besides, the best views—such as they are—will be from Europe and Africa.
Luckily there’s more to see—and learn about—in the night sky this week:
Monday, October 23: Moon And Saturn
A 70%-lit waxing gibbous moon will tonight shine brightly in the southeastern sky less than 3º from Saturn, which is just past its best for 2023 yet still looking fabulous in a small telescope. Look anytime after dark.
Saturday, October 28: Hunter’s Moon Eclipse And Jupiter
Tonight October’s full moon will drift into Earth’s shadow to cause a partial lunar eclipse, but unlike this month’s annular solar eclipse it’s Europe and Africa that are best placed to see it. From North America it won’t be much of a sight, with the full moon destined to rise while already exiting Earth’s fuzzy outer shadow.
However, a full moon rise is always worth watching and, as a bonus, Jupiter will be just 3º from it.
Stargazing Tip Of The Week: The Moon’s Libration
The moon is tidally locked to Earth so always shows the same face. However, there is some wriggle room—literally. As the moon moves around Earth it wobbles, something called libration, revealing in total about 59% of the surface over an entire year. This animation from NASA’s Goddard Space Flight Center, above, shows the moon in 2023 as a time-lapse, which as well as demonstrating its libration also reveals the location of its craters, lava seas and where NASA landed its Apollo missions in the 1960s and 1970s.
Object Of The Week: The Andromeda Galaxy
The most distant object you can see with your naked eyes at around 2.5 million light-years, the Andromeda Galaxy—also known as M31—contains about a trillion stars and is the largest close galaxy in our Milky Way’s cosmic neighborhood. Any pair of binoculars should be able to make-out its bright core high in the northeastern sky after dark. Be patient—you’ll find it!
Times and dates given apply to mid-northern latitudes. For the most accurate location-specific information consult online planetariums like Stellarium and The Sky Live. Check planet-rise/planet-set, sunrise/sunset and moonrise/moonset times for where you are.
Wishing you clear skies and wide eyes.