X Ray Moon
2.09.2000

This x-ray image of the Moon was made by the orbiting ROSAT (Röntgensatellit) Observatory in 1990. In this digital picture, pixel brightness corresponds to x-ray intensity. Consider the image in three parts: the bright hemisphere of the x-ray moon, the darker half of the moon, and the x-ray sky background.

Sun Halo over Sweden
1.01.2018

What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. In the featured video, however, there are actually millions of tiny lenses: ice crystals. Water may freeze in the atmosphere into small, flat, six-sided, ice crystals.

Protoplanetary Survivors in Orion
4.05.2001

The Orion Nebula is a nuturing stellar nursery filled with hot young stars and their natal clouds of gas and dust. But for planetary systems, the active star-forming region can present a hazardous and inhospitable birthplace.

NGC 6946: The Fireworks Galaxy
25.01.2005

Why is this galaxy so active? Nearby spiral galaxy NGC 6946 is undergoing a tremendous burst of star formation with no obvious cause. In many cases spirals light up when interacting with another galaxy, but NGC 6946 appears relatively isolated in space.

The Dance of Venus and Earth
3.06.2020

Every time Venus passes the Earth, it shows the same face. This remarkable fact has been known for only about 50 years, ever since radio telescopes have been able to peer beneath Venus' thick clouds and track its slowly rotating surface. This inferior conjunction -- when Venus and Earth are the closest -- occurs today.

A Space Station Crosses a Busy Sun
11.04.2022

Typically, the International Space Station is visible only at night. Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot several times a year from many locations.

A Spring Sky Over Hirsau Abbey
6.05.2009

What's in the sky tonight? When strolling outside just after sunset, even if just going out to your car, a casual glance upwards can reveal a beautiful night sky also seen by many people across the Earth.

Jupiter and the Moons
5.10.2019

After sunset on October 3, some of the Solar System's largest moons stood low along the western horizon with the largest planet. Just after nightfall, a pairing of the Moon approaching first quarter phase and Jupiter was captured in this telephoto field of view.

Sun Halo over Sweden
28.12.2021

What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. In the featured video, however, there are actually millions of tiny lenses: ice crystals. Water may freeze in the atmosphere into small, flat, six-sided, ice crystals.

APOD: 2023 May 8 Б The Spanish Dancer Spiral Galaxy
8.05.2023

If not perfect, then this spiral galaxy is at least one of the most photogenic. An island universe containing billions of stars and situated about 40 million light-years away toward the constellation of the Dolphinfish (Dorado), NGC 1566 presents a gorgeous face-on view.