Chart showing southwestern evening sky on September 22, 2020.

Earth in the balance today

Guy Ottewell’s insights on today’s autumnal equinox.

A woman standing on an ocean pier, throwing a net toward a red sun in a red sky.

September equinox: All you need to know

The equinox is September 22.

A colorful, ring-shaped cloud in space.

What are white dwarf stars?

White dwarfs are dead stars. A single white dwarf contains roughly the mass of our sun in a volume no bigger than our planet. Our sun will become a white dwarf someday.

Are day and night equal at the equinox?

Equinox means “equal night.” And you might hear that day and night are equal at the equinoxes. Yet Earth’s atmosphere and our sun team up to give us more day than night at an equinox.

Zodiacal light: All you need to know

The zodiacal light is an eerie light extending up from the horizon before true dawn begins. Southern Hemisphere? Look after sunset!

Comet in the sky above a lake, also reflecting in the lake.

What are comets?

Comets are loosely packed balls of ice and dust orbiting our sun, that sometimes become visible in Earth’s skies. A comet’s tail may stretch across millions of miles of space.

Chart showing Jupiter and Saturn on the night of September 10, 2020, and depicting Capricornus in the shape of an arrowhead.

2020 is your year to see Capricornus

Poor Capricornus. The early Greek stargazers labeled it as a Sea Goat, but no amount of squinting – or even imagining – can help you see a Goat in this part of the sky. In 2020, Jupiter and Saturn come to the rescue!

See Messier 20, the Trifid Nebula

If you have an extremely dark sky, you can see the nebula on as a fuzzy patch in the Milky Way. Binoculars show more … and a telescope still more.

Moon and Mars rising above a ridgeline, with a glorious display of northern lights in the background.

It’s time to start watching Mars

If you missed Mars last weekend near the moon, don’t worry. Mars is very bright and very red now. You can’t miss it in the night sky. By October, it’ll outshine Jupiter! Start watching it now, and enjoy the fun.

Photos of the moon’s sweep past bright Mars

Earth will pass between Mars and the sun in October 2020, and the distance between our 2 worlds is now relatively small. And so Mars is very bright now! Thanks to all in the EarthSky Community who captured Mars near the moon this past weekend.

September 2020 guide to the bright planets

Mercury, Jupiter and Saturn are in the sky at dusk throughout September 2020, with Mercury hard to view from northerly latitudes. Bright Mars rises in the east in the early evening. Brilliant Venus rides high in the east in the hours before sunrise.

Looking edgewise into the Milky Way

These stunning photos – taken by the talented photographers in our own EarthSky community – are from earlier this month, when the moon was less bright in the evening sky. See the Milky Way – the edgewise view into our own galaxy – plus Jupiter, Saturn and meteors here!

A star field showing brighter blue stars concentrated at the center, with a sparser scattering of fainter reddish, yellow, and blue stars.across the image.

Messier 11 is the Wild Duck Cluster

Messier 11 is a faint cluster of stars in a star-rich region of the night sky, in the direction of the heart of our Milky Way galaxy.

Born under the sign of Ophiuchus?

Born between November 29 and December 18? If so, the sun passes in front of Ophiuchus on your birthday.

Andromeda galaxy and the Milky Way - both as we see them in our sky - shown close together, appearing to begin a merger.

Earth’s night sky as Milky Way and Andromeda merge

Billions of years from now, Earth’s night sky will change as the Andromeda galaxy rushes toward a merger with the Milky Way.

Sagittarius? Here’s your constellation

How to find Sagittarius on August evenings, plus the lore and science of this constellation.

Visualize the Perseid meteor stream in space

This visualization by Ian Webster and Peter Jenniskens uses NASA data to render known Perseid meteoroids in space. Don’t miss this!

Perseid meteors 2020: All you need to know

In 2020, the peak mornings for the Perseid meteor shower – August 11, 12 and 13 – will feature meteors under moonlight. Still, the Perseids are bright. We expect a good number to overcome the moonlight. Here’s how to optimize your chances.

A ball of stars: globular cluster M13

What is a globular cluster?

Unlike the open star clusters – containing sibling stars, scattered through the disk of our galaxy and presumably other galaxies – globular clusters are big, symmetrical and old, like an earthly city’s oldest and most staid citizens.

Mars big as the moon on August 27?

We can’t believe it. One of the most popular articles at EarthSky this week is the one asking, will Mars be as big as the moon on August 27? Short answer … no. This hoax has been circulating since 2003.