Morning, Moon, and Mercury
26.04.2012

Last week Mercury wandered far to the west of the Sun. As the solar system's innermost planet neared its greatest elongation or greatest angle from the Sun (for this apparition about 27 degrees) it was joined by an old crescent Moon.

A Solstice Sunset Self Portrait
21.06.2013

Today, the solstice is at 05:04 Universal Time, the Sun reaching the northernmost declination in its yearly journey through planet Earth's sky. A June solstice marks the astronomical beginning of summer in the northern hemisphere and winter in the south.

A Solar Eclipse from the Moon
7.04.2014

Has a solar eclipse ever been seen from the Moon? Yes, first in 1967 -- but it may happen again next week. The robotic Surveyor 3 mission took thousands of wide angle television images of the Earth in 1967, a few of which captured the Earth moving in front of the Sun.

The Seasons of Saturn
2.07.2001

Soon it will be winter in Saturn's northern hemisphere. Since Saturn is tilted in its orbit around the Sun, it has seasons just like the Earth. When a hemisphere is tilted so that the Sun passes more directly overhead, summer occurs. Half an orbit later -- about 15 (Earth) years for Saturn -- winter occurs.

A Partial Eclipse in Southern Skies
3.09.1997

Location is everything, especially if you want to see a Solar Eclipse. These fleeting events are only visible to those in the path of the Moon's shadow as it races across the Earth.

APOD: 2025 September 6 Б Sardinia Sunset
6.09.2025

When the sun sets on September 7, the Full Moon will rise. And on that date denizens around much of our fair planet, including parts of Antarctica, Australia, Asia, Europe, and Africa can witness a total lunar eclipse, with the Moon completely immersed in Earth's shadow.

Comet Ikeya Zhang over Tenerife
26.03.2002

Comet Ikeya-Zhang has become bright enough to stand out in the night sky. Discovered February 1, the comet has now just rounded the Sun and has likely attained its peak brightness. The comet appears...

The Belt of Venus over Elwood Beach
9.08.2005

Although you've surely seen it, you might not have noticed it. During a cloudless twilight, just before sunrise or after sunset, part of the atmosphere above the horizon appears slightly off-color, slightly pink.

A Solar System Portrait
5.05.1999

As the Voyager 1 spacecraft headed out of our Solar System, it looked back and took a parting family portrait of the Sun and planets. From beyond Pluto, our Solar System looks like a bright star surrounded by faint dots. In the above picture, the Sun is so bright it is blocked out for contrast.

Closest Star has Potentially Habitable Planet
25.08.2016

The star closest to the Sun has a planet similar to the Earth. As announced yesterday, recent observations confirmed that this planet not only exists but inhabits a zone where its surface temperature could allow liquid water, a key ingredient for life on Earth.