Moon Shadow on Jupiter
27.04.2022

What is that large dark spot on Jupiter? It's the shadow of Io, one of Jupiter's largest moons. When Jupiter's moons cross between the Jovian giant and the Sun, they created shadows just like when the Earth's moon crosses between the Earth and the Sun.

Tololo Totality
15.03.2025

On March 14 the Moon was Full. In an appropriate celebration of Pi day, that put the Moon 3.14 radians (180 degrees) in ecliptic longitude from the Sun in planet Earth's sky.

Evolution of the Moon
20.03.2012

What is the history of the Moon? The Moon was likely created from debris expelled when a Mars-sized object violently impacted the Earth about 4.5 billion years ago. Just after gravitationally condensing, as imagined above, the glowing-hot surface of the Moon cooled and cracked.

Welcome Home Shannon Lucid
27.09.1996

Today is Shannon Lucid's first day on Planet Earth in six months. Her stay aboard Russia's Mir Space Station was of record length - the longest stay of any American in space ever.

The Largest Impact Crater
6.09.1996

What is the largest known impact crater in the Solar System? Over 1300 miles across, the South Pole-Aitken Basin on the farside of Earth's Moon holds that distinction. Circled above in a false color mosaic of Clementine images it was caused when an asteroid or comet sized object crashed

Space Station Vista: Planet and Galaxy
18.01.2017

If you could circle the Earth aboard the International Space Station, what might you see? Some amazing vistas, one of which was captured in this breathtaking picture in mid-2015. First, visible at the top, are parts of the space station itself including solar panels.

APOD: 2025 October 12 Б All the Water on Europa
12.10.2025

How much of Jupiter's moon Europa is made of water? No one is sure, but probably a lot. Based on the Galileo probe data acquired during its exploration of the Jovian system from 1995 to 2003, Europa possesses a deep, global ocean of liquid water beneath a layer of surface ice.

Storm Clouds Over Jupiter
27.11.1996

Storm clouds, similar to the familiar cumulonimbus thunderheads of Earth, appear to be present on Jupiter. The mosaic of images above shows the region near the raging edge of Jupiter's Great Red Spot, itself some 2 to 3 Earths wide, as observed by the Galileo spacecraft in June of this year.

Contrail Clutter over Georgia
13.10.2004

Artificial clouds made by humans may become so common they change the Earth's climate. The long thin cloud streaks that dominate the above satellite photograph of Georgia are contrails, cirrus clouds created by airplanes. The exhaust of an airplane engine can create a contrail by saturating the surrounding air with extra moisture.

Northern Spring on Mars
25.03.2006

Astronomical spring came to planet Earth's northern hemisphere this week (and autumn to the south) with the equinox on March 20th. But on Mars, northern spring began on January 22nd. Still in northern...