Lenticular Clouds Above Washington
3.02.2009

Are those UFOs near that mountain? No -- they are multilayered lenticular clouds. Moist air forced to flow upward around mountain tops can create lenticular clouds. Water droplets condense from moist air cooled below the dew point, and clouds are opaque groups of water droplets.

Apollo 11: Onto a New World
20.07.2009

A human first set foot on another world on July 20, 1969. This world was Earth's own Moon. In honor of today's 40th anniversary, NASA has released a digitally restored video of this milestone in human history. Pictured above is Neil Armstrong preparing to take the historic first step.

Millions of Stars in Omega Centauri
31.03.2010

Featured in the sharp telescopic image, globular star cluster Omega Centauri (NGC 5139) is some 15,000 light-years away and 150 light-years in diameter. Packed with about 10 million stars much older than...

Saturn s Serpent Storm
17.03.2011

Late last year, a new, remarkably bright storm erupted in Saturn's northern hemisphere. Nicknamed "the Serpent Storm", the northern hemisphere disturbance is still going strong and now circles far around the planet. Offering...

Ghost Aurora over Canada
31.10.2016

What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared. The aurora definitely appeared to be shaped like something , but what?

The Northern Winter Hexagon
26.12.2019

December's New Moon brought a solar eclipse to some for the holiday season. It also gave beautiful dark night skies to skygazers around the globe, like this moonless northern winter night. In the scene, bright stars of the Winter Hexagon along the Milky Way are rising.

Embraced by Sunlight
3.02.2022

Even though Venus (left) was the brightest planet in the sky it was less than 1/30th the apparent size of the Moon on January 29. But as both rose before the Sun they shared a crescent phase.

APOD: 2023 July 10 Б Stars, Dust and Nebula in NGC 6559
10.07.2023

When stars form, pandemonium reigns. A textbook case is the star forming region NGC 6559. Visible in the featured image are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them.

APOD: 2024 September 1 Б The Moon Dressed Like Saturn
1.09.2024

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight, known as Da Vinci glow.

M104: The Sombrero Galaxy
9.11.1995

The famous Sombrero galaxy (M104) is a bright nearby spiral galaxy. The prominent dust lane and halo of stars and globular clusters give this galaxy its name. Something very energetic is going on in the Sombrero's center, as much X-ray light has been detected from it.