Colors of the Moon
15.05.2022

What color is the Moon? It depends on the night. Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth's atmosphere, though, the moon can appear quite different.

Polaris: The North Star
6.10.1999

Polaris is quite an unusual star. First, Polaris is the nearest bright star to the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to rotate around Polaris, making it the North Star.

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.

Lapland Northern Lights
8.04.2016

Early spring in the northern hemisphere is good season for aurora hunters. Near an equinox Earth's magnetic field is oriented to favor interactions with the solar wind that trigger the alluring glow of the northern lights. On March 28/29 the skies over Kaunispää Hill, Lapland, Finland did not disappoint.

Good Morning Moon
12.01.2024

Yesterday, the Moon was New. But on January 9, early morning risers around planet Earth were treated to the sight of an old Moon, low in the east as the sky grew bright before dawn.

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.