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 and eclipses.
What To Watch For In The Night Sky This Week: September 21-27, 2020
This week sees the autumnal equinox, a celestial event that begins the astronomical season of fall. We earthlings will all get the same amount of sunlight, with the day and night of almost identical length (“equinox” comes from aequus and nox, Latin for equal and nox). Exactly halfway between the summer and winter solstice’s, it’s the point of the year when the Sun crosses the celestial equator heading south and Earth’s axis is side-on to the sun.
This week also has some visual treats in the night skies, with Mars shining brightly in the east after dark, and the Moon moving close to Jupiter and Saturn on successive nights as its passes it First Quarter phase.
Tuesday, September 22, 2020: Autumnal or Fall Equinox
At exactly 13:31 p.m. UTC, which is 9:15 a.m. EDT and 6.16 a.m. PDT the Sun will cross the celestial equator, moving south to create days and nights of virtually equal length for a short time. It’s a global event, so occurs simultaneously for everyone on the planet.
If you’re up early look to the east to see the planet Mercury close to Spica, the brightest star in Virgo and the 16th brightest in the night sky. You’ll need binoculars to pick-out Mercury.
After dark you’ll be able to see the Moon in the southwest just above Antares, the brightest star in the constellation of Scorpius. The 15th brightest star in the night sky, Antares is a red supergiant star 12 times the mass of the Sun. Look to the south and you’ll see bright Jupiter, then dimmer Saturn.
Thursday, September 24, 2020: Jupiter and the Moon
If you’re an evening stargazer then look to the southwest after dark tonight to see Jupiter and the Moon, the latter about 61% illuminated. If you have binoculars then point them at Jupiter; you should be able to see some of its four giant “Galilean” moons; Io, Callisto, Ganymede and Europa.
Friday, September 25, 2020: Saturn and the Moon
Get up early to see Jupiter 1.6° north of the Moon just before dawn, then return 14 hours later to see that a 68%-lit Moon has moved closer to Saturn. Saturn is 10 times dimmer than Jupiter and you’ll need a small telescope to see its rings.
Wishing you clear skies and wide eyes.