Menu

Sky Digest

Tuesday, 23 December 2025 | Default Location
Showing the sky from Greenwich, London. Log in to use your own location.
Excel

Tonight at a Glance

Waxing Crescent 13%
Dark window: 17:18 – 06:41 (13 h 23 m)

Planet Highlights

Jupiter mag -2.7 · 32° alt · Gemini Details
GRS transit tonight:
Io Shadow transit begins
Ganymede Occultation begins
Io Transit begins
Io Shadow transit ends
+4 more — Details
Saturn mag 0.9 · 20° alt · Aquarius Details
Rings: Edge-on (rings nearly invisible) (0.9° north face)

Comets

PANSTARRS mag 6.6 · 30° alt · Pegasus Details
bright 2.18 AU Perihelion: Apr 19 (in 19d)

For Beginners (naked eye)

Hyades
Open Cluster
mag 0.5

At 21:00 look high in the southeast

Taurus
M42
Great Orion Nebula Nebula
mag 4.0

At 21:00 look halfway up in the southeast

Orion
M31
Andromeda Galaxy Galaxy
mag 3.4

At 21:00 look high in the west

Andromeda

Binocular Targets

Mira
68 Cet Variable Star
mag 3.0

At 21:00 look halfway up in the south

Cet
M34
Spiral Cluster Open Cluster
mag 5.5

At 21:00 look near the zenith

Perseus
M81
Bode's Galaxy Galaxy
mag 6.9

At 21:00 look halfway up in the northeast

Ursa Major

Small Scopes (3–6 inch)

Castor
HIP 36850; Alpha Gem; 66 Gem Double Star
mag 2.0

At 21:00 look halfway up in the east

Gem
NGC 1245
Open Cluster
mag 8.4

At 21:00 look near the zenith

Per
M76
Little Dumbbell Nebula Planetary Nebula
mag 10.1

At 21:00 look near the zenith

Perseus
C5
IC 342 Galaxy
mag 9.2

At 21:00 look near the zenith

Camelopardalis
R Tri
Variable Star
mag 5.3

At 21:00 look near the zenith

Tri

Big Scopes (8–12 inch)

NGC 1220
Open Cluster
mag 12.0

At 21:00 look near the zenith

Per
C56
NGC 246 Planetary Nebula
mag 10.9

At 21:00 look low in the southwest

Cetus
C23
NGC 891 Galaxy
mag 9.9

At 21:00 look near the zenith

Andromeda
M74
Phantom Galaxy Galaxy
mag 9.4

At 21:00 look high in the southwest

Pisces
NGC 925
Galaxy
mag 10.0

At 21:00 look near the zenith

Tri

The Week Ahead

Tue Wed Thu Fri Sat Sun Mon
🌒 13% 🌒 21% 🌓 30% 🌓 40% 🌔 50% 🌔 61% 🌔 72%

NASA Astronomy Picture of the Day

Red Sprites and Circular Elves Lightning over Italy

What's happening in the sky? Lightning. The most commonly seen type of lightning involves flashes of bright white light between clouds. Over the past 50 years, though, other types of upper-atmospheric lightning have been confirmed, including tentacled red sprites and ringed ELVES. Although both last only a small fraction of a second, sprites are brighter and easier to photograph than their more common electrical-discharge cousins. ELVES are rapidly expanding rings that are thought to be created when an electromagnetic pulse shoots upward from charged clouds and impacts the ionosphere, causing nitrogen molecules to glow. Capturing either form of lightning takes patience and experience -- capturing them both together, since they usually occur separately, is rare. The featured image is a frame from a video recorded from Possagno, Italy late last month above a distant thunderstorm over the Adriatic Sea.

Image credit: Valter Binotto — APOD is a service of NASA and Michigan Tech. U.

View on NASA APOD

Space News

Sendoff for Artemis II Crew

NASA officially presents the Artemis II crew (Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen) ahead of their historic crewed mission around the Moon.

NASA — 30 Mar 2026

NASA Selects Intuitive Machines to Deliver Artemis Science, Tech to Moon

NASA awards Intuitive Machines $180.4 million to deliver science payloads to the lunar surface as part of the Commercial Lunar Payload Services initiative supporting the Artemis program.

NASA — 27 Mar 2026

NASA Releases Artemis II Moon Mission Launch Countdown

NASA releases the launch countdown timeline for Artemis II, targeting no earlier than April 1, 2026, for the first crewed lunar mission in over 50 years.

NASA — 26 Mar 2026

NASA Names Scientists to Support Lunar South Pole Science

NASA selects 10 scientists to develop the lunar south pole science plan for Artemis astronauts, including instrument deployment and sample collection on the Moon.

NASA — 27 Mar 2026

Plan your session before dark

Use Tonight to find targets, then add them to a Plan so you have a checklist ready when you're outside.

Open Tonight

Sign in to get this digest by email and customize it for your location.