Moons at Twilight
4.02.2022

Even though Jupiter was the only planet visible in the evening sky on February 2, it shared the twilight above the western horizon with the Solar System's brightest moons. In a single exposure...

Enhanced Color Caloris
4.03.2015

The sprawling Caloris basin on Mercury is one of the solar system's largest impact basins, created during the early history of the solar system by the impact of a large asteroid-sized body.

Hale Bopp: A Continuing Tail
20.02.1998

Where is Hale-Bopp now? The Great Comet of 1997, one of the largest and most active comets ever, is outbound about 400 million miles from the sun. Too faint for viewing without telescopes or binoculars, Hale-Bopp is presently positioned in the very southerly constellation of Pictor.

Vega and Comet 12P Pons-Brooks
8.12.2023

On December 4, periodic Comet 12P/Pons-Brooks shared this telescopic field of view with Vega, alpha star of the northern constellation Lyra. Fifth brightest star in planet Earth's night, Vega is some 25 light-years distant while the much fainter comet was about 21 light-minutes away.

The Ecliptic Plane
27.09.1997

The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the Sun's corona rising over the Moon's dark limb, and the planets Saturn, Mars, and Mercury.

The Ecliptic Plane
29.05.1999

The Plane of the Ecliptic is illustrated in this Clementine star tracker camera image which reveals (from right to left) the Moon lit by Earthshine, the Sun's corona rising over the Moon's dark limb, and the planets Saturn, Mars, and Mercury.

Callisto Enhanced
12.05.1998

Callisto is half rock and half ice. This moon of Jupiter is approximately the size of the planet Mercury, making it the third largest moon in the Solar System, after Ganymede and Titan. Callisto...

APOD: 2025 November 17 Б Comet Lemmons Wandering Tail
17.11.2025

What has happened to Comet Lemmon's tail? The answer is blowing in the wind Б the wind from the Sun in this case. This continuous outflow of charged particles from...

The Sun Today
18.05.1996

Our Sun shows a different face every day. The above picture was taken on May 15, but a similar picture of the Sun actually taken today can be found here. The above picture was taken in red light and so is shown in red.

An Orbiting Iceberg
21.08.1995

A comet nucleus, formed from the primordial stuff of the solar system, resembles a very dirty iceberg. Orbiting far from our Sun, it can remain frozen, preserved for billions of years. Occasionally, a chance gravitational encounter will alter this distant orbit and send the nucleus plummeting towards the inner solar system.