Orion over Green Bank
23.02.2022

What will the huge Green Bank Telescope discover tonight? Pictured, the Robert C. Byrd Green Bank Telescope (GBT) on the lower right is the largest fully-pointable single-dish radio telescope in the world. With...

Phases of Venus
17.03.2017

Just as the Moon goes through phases, Venus' visible sunlit hemisphere waxes and wanes. This composite of telescopic images illustrates the steady changes for the inner planet, seen in the west as the evening star, as Venus grows larger but narrows to a thin crescent from December 20, 2016 through March 10.

Spiral Galaxy NGC 3310 Across the Visible
11.09.2001

The party is still going on in spiral galaxy NGC 3310. Roughly 100 million years ago, NGC 3310 likely collided with a smaller galaxy causing the large spiral galaxy to light up with a tremendous burst of star formation.

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.