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Slanted shot shows black space over the gray, cratered horizon of Mercury

Solar System

Do Glaciers on Mercury Suggest Such a Planet Could Be Habitable?

Salt glaciers on Mercury suggest conditions friendly to life — but not life itself — might once have existed on the innermost planet.

First look at Dinkinesh and its satellite

Solar System

Amateur Astronomers Discover an Asteroid’s Moon

The small object orbiting around main-belt asteroid 5457 Queen’s is the second confirmed asteroid moon discovered during a stellar occultation.

Moon passing Jupiter, Nov. 24-25, 2023

This Week's Sky At a Glance

This Week's Sky at a Glance, November 24 – December 3

This Tuesday the 28th we will see the Moon rise in twilight as far north as it possibly can. Do you know why?

A dot of light marks the 5.3-kilometer asteroid Seronik

People, Places, and Events

Asteroid Named for Sky & Telescope’s Gary Seronik

The International Astronomical Union has named the asteroid provisionally designated as 1993 FE15 after Sky & Telescope's Consulting Editor Gary Seronik: 20046 Seronik.

white flare of light at left gives rise to spiral jet going off to the right

Stellar Science

Astronomers Find a Brilliant Explosion That Just Keeps On Exploding

A brilliant flash of blue light briefly outshined its host galaxy before fading away — but then it exploded again and again, shedding light on the nature of its source.

Babylonian clay tablet recording eclipses

Celestial News & Events

How Did the Ancients Predict Eclipses? The Saros Cycle

Before the advent of computers or even a working theory of the solar system, the ancients predicted solar eclipses. How did they do it?

Titania from Voyager 2

Occultations

Watch Uranus's Moon Titania Cover a Star Monday Night

Observers across much of the U.S. and Canada have a unique opportunity Monday night, November 20–21, to see Uranus's brightest moon occult a star.

This Week's Sky At a Glance

This Week's Sky at a Glance, November 17 – 26

The bright gibbous Moon this week passes Saturn, then Jupiter, inviting telescopes of all sizes. And as winter approaches, Orion rises earlier and earlier.

Ryugu

Astronomy in Space with David Dickinson

Samples of Asteroid Ryugu Show Signs of Ancient Water

The distribution of elements seen in the samples of Ryugu brought back by Hayabusa 2 hints at a wet past.

artist's impression of weird inflated planet

Exoplanets

Webb Telescope Peers into Puffy Planet with Clouds of Sand

A mere 200 light-years away, there's a planet with the density of styrofoam and clouds of sand. How did it get so weird?

GRS 2017 Juno

Explore the Night with Bob King

Jupiter's Great Red Spot Just Keeps Getting Smaller

Jupiter's Great Red Spot may be reaching a milestone this year by shrinking to its smallest size in recorded observational history.

Gibbous Venus from Akatsuki

Solar System

Atomic Oxygen Detected on Venus

New data provide direct evidence for the existence of atomic oxygen in Venus's upper atmosphere, enabling new science on our sister planet.

Planet-forming disks

Exoplanets

Webb Shows Planets Really Do Start with Pebbles

New observations have turned up evidence that icy pebbles deliver the water to inner regions of planet-forming disks.

Celestial News & Events

Asteroid Will Cover Betelgeuse, May Reveal Its Visible Surface

Astronomers are gearing up for an unusual celestial event: an asteroid’s occultation of an iconic star.

First-quarter Moon passing Saturn at quadrature, Nov. 19-20, 2023

This Week's Sky At a Glance

This Week's Sky at a Glance, November 10 – 19

The crescent Moon slips down into the sunrise and then up in the afterglow of sunset, guiding the way to the last stars of Sagittarius right after dark. A few days later it passes Saturn.

Galaxy cluster

Galaxies

Webb, Hubble Telescopes Team Up to Create "Most Colorful View of the Universe"

The Hubble and Webb Space Telescopes have revealed a bounty of galaxies in a pair of colliding clusters, capturing twinkling lights within.

Enif

Celestial Objects to Observe

Meet Enif, the Nose of Pegasus

Enif, the nose of Pegasus, is a supergiant star and the brightest member of the constellation. Find out more about this star and its place in our skies.

Dinkinesh and its contact-binary moon

Space Missions

Lucy Mission Flies By Asteroid Dinkinesh, Finds Binary Moon (Updated)

The Lucy mission's flyby of the main-belt asteroid Dinkinesh resulted in a surprise — yet another asteroid moon!

Horsehead Nebula

Galaxies

New Cosmology Probe Presents First, Stunning Images

The Horsehead Nebula and other stunning scenes highlight the talents of the just-launched Euclid mission. The telescope will reach into the depths of the cosmos to understand dark matter and dark energy.

Catch the Moon-Venus pairing at dawn Nov 9, 2023

This Week's Sky At a Glance

This Week's Sky at a Glance, November 3 – 12

The Great Square, now upright, guides your way down to Fomalhaut and Diphda and, farther down, Alpha Phoenicis – a chance to add a new constellation to your life list. And plan to catch the Moon-Venus pairing in early dawn on the 9th.

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