A Superior Conjunction Of Mercury
8.09.1999

In astronomical parlance, an interior planet is at superior conjunction when it is located on the opposite side of the Sun from Earth. Mercury, the solar system's innermost planet, zips past this point in its orbit today.

Rigel and the Witch Head Nebula
29.12.2009

Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula on the lower left is associated with the bright star Rigel, to its right, in the constellation Orion.

The Shark Nebula
7.09.2015

There is no sea on Earth large enough to contain the Shark nebula. This predator apparition poses us no danger, though, as it is composed only of interstellar gas and dust. Dark dust like that featured here is somewhat like cigarette smoke and created in the cool atmospheres of giant stars.

A Colorful Solar Corona over the Himalayas
11.01.2016

What are those colorful rings around the Sun? A corona visible only to Earth observers in the right place at the right time. Rings like this will sometimes appear when the Sun or Moon is seen through thin clouds.

Titan: Moon over Saturn
9.01.2021

Like Earth's moon, Saturn's largest moon Titan is locked in synchronous rotation. This mosaic of images recorded by the Cassini spacecraft in May of 2012 shows its anti-Saturn side, the side always facing away from the ringed gas giant.

Perseid Rain
15.08.2021

Comet dust rained down on planet Earth last week, streaking through dark skies in the annual Perseid meteor shower. The featured picture is a composite of many images taken from the same location over the peak night of the Perseids.

Bright Meteor, Starry Sky
19.08.2021

Plowing through Earth's atmosphere at 60 kilometers per second, this bright perseid meteor streaks along a starry Milky Way. Captured in dark Portugal skies on August 12, it moves right to left through the frame.

Sunrise at the South Pole
5.10.2021

Sunrise at the South Pole is different. Usually a welcome sight, it follows months of darkness -- and begins months of sunshine. At Earth's poles, it can take weeks for the Sun to rise, in contrast with just minutes at any mid-latitude location.

Aurora and Light Pillars over Norway
8.02.2022

Which half of this sky is your favorite? On the left, the night sky is lit up by particles expelled from the Sun that later collided with Earth's upper atmosphere Б creating bright auroras.

Titan: Moon over Saturn
27.05.2022

Like Earth's moon, Saturn's largest moon Titan is locked in synchronous rotation. This mosaic of images recorded by the Cassini spacecraft in May of 2012 shows its anti-Saturn side, the side always facing away from the ringed gas giant.