Lunation Matrix
1.10.2022

Observe the Moon every night and you'll see its visible sunlit portion gradually change. In phases progressing from New Moon to Full Moon to New Moon again, a lunar cycle or lunation is completed in about 29.5 days.

APOD: 2024 March 17 Б NGC 7714: Starburst after Galaxy Collision
17.03.2024

Is this galaxy jumping through a giant ring of stars? Probably not. Although the precise dynamics behind the featured image is yet unclear, what is clear is that the pictured galaxy, NGC 7714, has been stretched and distorted by a recent collision with a neighboring galaxy.

APOD: 2026 February 16 Б Unexplained Shocks Around a White Dwarf Star
16.02.2026

How is RXJ0528+2838 creating such shock waves? A recently discovered white dwarf star, the farther left of the two largest white spots, RXJ0528+2838, was found 730 light-years away from Earth. Most stars...

Stardust Capsule Returns to Earth
16.01.2006

A flying saucer from outer space crash-landed in the Utah desert yesterday after being tracked by radar and chased by helicopters and airplanes. Like last time, no space aliens were involved. The saucer...

Three Years of Saturn
7.04.2007

Using an image recorded just last month as a base, this composite illustration tracks the motion of bright Saturn as it wanders through planet Earth's night sky. Starting at the upper right, Saturn's position is shown about every two weeks beginning in August 2005 and projected through September 2008.

Dust and the Helix Nebula
31.12.2009

Dust makes this cosmic eye look red. The eerie Spitzer Space Telescope image shows infrared radiation from the well-studied Helix Nebula (NGC 7293) a mere 700 light-years away in the constellation Aquarius.

Lenticular Cloud, Moon, Mars, Venus
1.03.2015

It is not every day that such an interesting cloud photobombs your image. The original plan was to photograph a rare angular conjunction of Mars and Venus that occurred a week and a half ago, with the added bonus of a crescent Moon and the International Space Station (ISS) both passing nearby.

The Helix Nebula in Infrared
20.09.2016

What makes this cosmic eye look so red? Dust. The featured image from the robotic Spitzer Space Telescope shows infrared light from the well-studied Helix Nebula (NGC 7293) a mere 700 light-years away in the constellation of the Water Carrier Aquarius.

M27 Not a Comet
9.06.2017

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things he encountered that were definitely not comets. This is number 27 on his now famous not-a-comet list.

Moon Phases 2022
1.02.2022

What will the Moon phase be on your birthday this year? It is hard to predict because the Moon's appearance changes nightly. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible.