Over the Top
19.06.2014

The central bulge of our Milky Way Galaxy rises above a sea of clouds in this ethereal scene. An echo of the Milky Way's dark dust lanes, the volcanic peak in foreground silhouette is on France's Réunion Island in the southern Indian Ocean.

Lapland Northern Lights
8.04.2016

Early spring in the northern hemisphere is good season for aurora hunters. Near an equinox Earth's magnetic field is oriented to favor interactions with the solar wind that trigger the alluring glow of the northern lights. On March 28/29 the skies over Kaunispää Hill, Lapland, Finland did not disappoint.

A Full Sky Aurora Over Norway
1.01.2017

Higher than the highest building, higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking molecules in the Earth's atmosphere.

Eclipse under the ISS
27.06.2020

The dark shadow of the New Moon reached out and touched planet Earth on June 21. A high definition camera outside the International Space Station captured its passing in this snapshot from low Earth orbit near the border of Kazakhstan and China.

Good Morning Moon
12.01.2024

Yesterday, the Moon was New. But on January 9, early morning risers around planet Earth were treated to the sight of an old Moon, low in the east as the sky grew bright before dawn.

Long Shadows of the Montes Caucasus
19.12.2025

When the Moon is at its first quarter phase, the Sun rises along the Montes Caucasus as seen from the lunar surface. The lunar mountain range casts the magnificent, spire-like shadows in this telescopic view from planet Earth, looking along the lunar terminator or the boundary between lunar night and day.

Big Mars from Hubble
27.08.2003

At about 10 am Universal Time today, Mars and Earth will pass closer than in nearly 60,000 years. Mars, noticeably red, will be the brightest object in the eastern sky just after sunset.

Comet C 2002 T7 (LINEAR)
22.04.2004

Discovered by the the Lincoln Near Earth Asteroid Research (LINEAR) project in October of 2002, comet C/2002 T7 is now visiting the inner solar system, making its closest approach (see animation by L. Koehn) to the Sun tomorrow, April 23rd.

Highlights of the North Spring Sky
13.03.2019

What can you see in the night sky this season? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) spring sky events fan out toward the left, while late spring events are projected toward the right.

APOD: 2023 May 2 Б Flat Rock Hills on Mars
2.05.2023

Why are there so many flat rocks on Mars? Some views of plains and hills on Mars show many rocks that are unusually flat when compared to rocks on Earth. One reason for this is a process that is common to both Mars and Earth: erosion.