MESSENGER s First Day
8.10.2011

One solar day on a planet is the length of time from noon to noon. A solar day lasts 24 hours on planet Earth. On Mercury a solar day is about 176 Earth days long.

Cosmic Rays at Voyager 1
8.09.2012

Launched on a grand tour of the outer planets in 1977, by good fortune the twin Voyager spacecraft were also headed in the general direction of the Sun's motion relative to nearby stars. Thirty five years later, Voyager 1 appears to be nearing the boundary of the Sun's heliosphere and interstellar space.

The Map of Dione
6.11.2014

This cylindrical projection global map is one of six new color maps of Saturn's midsized icy moons, constructed using 10 years of image data from the Cassini spacecraft. Discovered by Cassini (the astronomer) in 1684, Dione is about 1,120 kilometers across.

Equinox on a Spinning Earth
19.03.2017

When does the line between day and night become vertical? Tomorrow. Tomorrow is an equinox on planet Earth, a time of year when day and night are most nearly equal. At an equinox, the Earth's terminator -- the dividing line between day and night -- becomes vertical and connects the north and south poles.

Young Star Cluster Trumpler 14 from Hubble
14.05.2019

Why does star cluster Trumpler 14 have so many bright stars? Because it is so young. Many cluster stars have formed only in the past 5 million years and are so hot they emit detectable X-rays.

Barred Spiral Galaxy NGC 6217
21.02.2022

Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 6217, featured here, was captured in spectacular detail in this image taken by the Advanced Camera for Surveys on the orbiting Hubble Space Telescope in 2009.

APOD: 2025 November 30 Б The Surface of Titan from Huygens
30.11.2025

If you could stand on Titan -- what would you see? The featured color viewa from Titan gazes across an unfamiliar and distant landscape on Saturn's largest moon. The scene was recorded by ESA's Huygens probe in 2005 after a 2.5-hour descent through a thick atmosphere of nitrogen laced with methane.

Streaming From A Black Hole
13.06.1997

Glowing gas clouds are streaming from the core of galaxy NGC4151 at hundreds of thousands of miles per hour. A powerful tool, the Hubble Space Telescope's new STIS instrument, makes it possible to map out the cloud velocities - producing this false color "velocity map" for the central regions of NGC4151.

The Barren Moon
3.01.1998

The above photo, taken as the Apollo 17 astronauts orbited the Moon in 1972, depicts the stark lunar surface around the Eratosthenes and Copernicus craters. Many similar images of a Moon devoid of life are familiar to denizens of the space age.

Discovery Image: Comet SOHO (1998 J1)
20.05.1998

Staring at the Sun from a vantage point in space (Kids, don't try this at home!), the Solar and Heliospheric Observatory (SOHO) has enabled the discovery of much about our closest star. It has also been used to discover about 50 comets.