Aphelion Sunrise
5.07.2017

On July 3rd, planet Earth reached aphelion, the farthest point in its elliptical orbit around the Sun. Each year, this day of the most distant Sun happens to occur during winter in the southern hemisphere.

APOD: 2025 September 30 Б Comet Lemmon Brightens
30.09.2025

Comet Lemmon is brightening and moving into morning northern skies. Besides Comet SWAN25B and Comet ATLAS, Comet C/2025 A6 (Lemmon) is now the third comet currently visible with binoculars and on long camera exposures. Comet Lemmon was discovered early this year and is still headed into the inner Solar System.

A Volcanic Great Conjunction
20.12.2020

Where can I see the Great Conjunction? Near where the Sun just set. Directionally, this close passing of Jupiter and Saturn will be toward the southwest. Since the planetary pair...

Leaving the International Space Station
17.12.2001

It was time to go home. During their eight days aboard the Earth-orbiting International Space Station (ISS), ESA Flight Engineer Claudie Haigner, Russian Commander Victor Afanasyev, and Russian Flight Engineer Konstantin Kozeev had completed several experiments and successfully delivered a new lifeboat.

Starry Night over Dubai
16.07.2011

A starry night over the city of Dubai in the United Arab Emirates is really not so starry. In fact, the Moon is the only celestial beacon to come close to competing with city lights in this night skyscape, a situation all too familiar to urban skygazers.

Clouds and Crescents
4.01.2014

A crescent Venus shines along the western horizon at dusk in this clearing sky. The Earth's sister planet is smiling between the low clouds near the bottom of the frame during its January 2nd conjunction with the slender, young crescent Moon above.

The Aurora Tree
28.02.2021

Yes, but can your tree do this? Pictured is a visual coincidence between the dark branches of a nearby tree and bright glow of a distant aurora. The beauty of the aurora -- combined with...

The Compton Gamma Ray Observatory
11.08.1995

The Compton Gamma Ray Observatory (CGRO) was the most massive instrument ever launched by a NASA Space Shuttle and continues to revolutionize gamma-ray astronomy. This orbiting observatory sees the sky in gamma-ray photons - light so blue humans can't see it.

Night Lightning on Jupiter
16.12.1997

Why is there lightning on Jupiter? Lightning is a sudden rush of electrically charged particles from one location to another. To create lightning, charges must first separate inside a cloud. On Earth, drafts of colliding ice and water droplets usually create this charge separation, but what happens on Jupiter?

Leonids 1998: A Safe Meteor Storm
16.11.1998

You're in no danger. During the meteor storm occurring tonight and tomorrow, thousands of bits of ice and rock will likely rain onto the Earth. Few, if any, will hit the ground. Touted as potentially the most active meteor shower since 1966, the Leonids of 1998 will be tracked by observers the world over.