APOD: 2024 December 4 Б Driveway Analemma
4.12.2024

Does the Sun return to the same spot on the sky every day?б No.б A more visual answer is an analemma, a composite of sky images taken at the same time and from the same place over a year.

The Trail of the Intruder
24.02.1997

In yesterday's episode our hero, the Cartwheel galaxy, had survived a chance cosmic collision with a small intruder galaxy - triggering an expanding ring of star formation. Hot on the intruder's trail, a team of multiwavelength sleuths have compiled evidence tracking the reckless galaxy fleeing the scene.

Arches Across an Arctic Sky
13.01.2021

What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky.

Beneath Venus' Clouds
24.09.1996

If the thick clouds covering Venus were removed, how would the surface appear? Using an imaging radar technique, the Magellan spacecraft was able to lift the veil from the Face of Venus and produce this spectacular high resolution imageof the planet's surface.

Star Factory Messier 17
18.04.2013

Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this degree wide field of view spans almost 100 light-years.

Halley Dust and Milky Way
10.05.2019

Grains of cosmic dust streaked through the mostly moonless night skies of May 7. Swept up as planet Earth plowed through the debris streams left behind by periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids.

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...