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
18.03.2017

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.

Barred Spiral Galaxy NGC 6217
20.02.2022

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.

The Barren Moon
2.01.1998

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.

Three Kilometers Above Titan
18.05.2005

What did the Huygens probe see as it descended toward Saturn's Moon Titan? In January the robot Cassini spacecraft now orbiting Saturn released a probe through the dense cloud decks of one of the Solar System's most mysterious moons.

Perseid Prelude
12.08.2010

Each August, as planet Earth swings through dust trailing along the orbit of periodic comet Swift-Tuttle, skygazers can enjoy the Perseids Meteor Shower. The shower should build to its peak now, best seen from later tonight after moonset, until dawn tomorrow morning when Earth moves through the denser part of the wide dust trail.

The Opposing Tails of Comet Garradd
28.02.2012

Why does Comet Garradd have two tails? Visible on the left, Comet Garradd's dust tail is composed of ice and dust bits that trial the comet in its orbit around the Sun. Visible...

The Flight Deck of Space Shuttle Endeavour
18.04.2012

What would it be like to fly a space shuttle? Although the last of NASA's space shuttles has now been retired, it is still fun to contemplate sitting at the controls of one of the humanity's most sophisticated machines.

In the Shadow of Saturn
13.11.2013

In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn drifted in giant planet's shadow earlier this year and looked back toward the eclipsed Sun. Cassini saw a unique and celebrated view.

Mystery Feature Now Disappears in Titan Lake
6.03.2016

What is that changing object in a cold hydrocarbon sea of Titan? Radar images from the robotic Cassini spacecraft orbiting Saturn have been recording the surface of the cloud-engulfed moon Titan for years. When...