Moon Over Andromeda
28.12.2006

The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small...

Geminid Meteors over Xinglong Observatory
13.12.2020

Where do Geminid meteors come from? In terms of location on the sky, as the featured image composite beautifully demonstrates, the sand-sized bits of rock that create the streaks of the Geminids meteor shower appear to flow out from the constellation of Gemini.

APOD: 2023 August 9 Б Meteor Shower: Perseids from Perseus
9.08.2023

This is a good week to see meteors. Comet dust will rain down on planet Earth, streaking through dark skies during peak nights of the annual Perseid Meteor Shower. The featured composite image was taken during the 2018 Perseids from the Poloniny Dark Sky Park in Slovakia.

APOD: 2023 September 18 Б The Red Sprite and the Tree
18.09.2023

The sprite and tree could hardly be more different. To start, the red sprite is an unusual form of lightning, while the tree is a common plant. The sprite is far away -- high in Earth's atmosphere, while the tree is nearby -- only about a football field away.

APOD: 2025 July 27 Б Lightning over the Volcano of Water
27.07.2025

Have you ever watched a lightning storm in awe? You're not alone. Details of what causes lightning are still being researched, but it is known that inside some clouds, internal updrafts cause collisions between ice and snow that slowly separate charges between cloud tops and bottoms.

A Meteor Wind over Tunisia
16.08.2022

Does the Earth ever pass through a wind of meteors? Yes, and they are frequently visible as meteor showers. Almost all meteors are sand-sized debris that escaped from a Sun-orbiting comet or asteroid, debris that continues in an elongated orbit around the Sun.

Hercules Galaxies
27.08.1998

These are galaxies of the Hercules Cluster, an archipelago of "island universes" a mere 650 million light-years distant. This cluster is loaded with gas and dust rich, star forming, spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars.

A Glowing STEVE and the Milky Way
17.11.2020

What's creating these long glowing streaks in the sky? No one is sure. Known as Strong Thermal Emission Velocity Enhancements (STEVEs), these luminous light-purple sky ribbons may resemble regular auroras, but recent research reveals significant differences.

30 Doradus Across the Spectrum
24.12.1997

30 Doradus is lit up like a Christmas tree. Shining in light across the electromagnetic spectrum, 30 Doradus glows because of all the energetic processes that go on there. A distinctive region visible...

NGC 3324 in Carina
6.04.2018

This bright cosmic cloud was sculpted by stellar winds and radiation from the hot young stars of open cluster NGC 3324. With dust clouds in silhouette against its glowing atomic gas, the pocket-shaped star-forming region actually spans about 35 light-years. It lies some 7,500 light-years away toward the nebula rich southern constellation Carina.