A High Energy Fleet
24.05.1998

Looking like a fleet of futuristic starcruisers, NASA's highly successful series of High Energy Astrophysical Observatory (HEAO) spacecraft appear poised over planet Earth. Labeled A, B, and C in this vintage illustration, the spacebased telescopes were known as HEAO-1, HEAO-2, and HEAO-3 respectively.

Glimpse of a Globular Star Cluster
14.10.2004

Not a glimpse of this cluster of stars can be seen in the inset visible light image (lower right). Still, the infrared view from the Spitzer Space Telescope reveals a massive globular star cluster of about 300,000 suns in an apparently empty region of sky in the constellation Aquila.

A Wavemaker Moon in Saturns Rings
23.05.2005

What causes small waves in Saturn's rings? Observations of rings bordering the Keeler gap in Saturn's rings showed unusual waves. Such waves were first noticed last July and are shown above in clear detail.

50 Years Ago: Yuri s Planet
12.04.2011

On April 12th, 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human in space. His remotely controlled Vostok 1 spacecraft lofted him to an altitude of 200 miles and carried him once around planet Earth. Commenting on the first view from space he reported, "The sky is very dark; the Earth is bluish.

A Flight of Helios
24.07.2011

An example of solar-powered flight, NASA's Helios aircraft flew almost one hundred years after the Wright brothers' historic flight on December 17, 1903. Pictured here at 3,000 meters in in skies northwest of Kauai, Hawaii, USA in August 2001, the remotely piloted Helios is traveling at about 40 kilometers per hour.

The Cloudy Cores of Active Galaxies
24.02.2014

What would it look like to travel to the center of an active galaxy? Most galactic centers are thought to house black holes millions of times more massive than our Sun. The spaces surrounding...

The Andromeda Galaxy in Ultraviolet
17.07.2021

What does the Andromeda galaxy look like in ultraviolet light? Young blue stars circling the galactic center dominate. A mere 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go.

The Tarantula Nebula from SuperBIT
26.04.2023

The Tarantula Nebula, also known as 30 Doradus, is more than a thousand light-years in diameter, a giant star forming region within nearby satellite galaxy the Large Magellanic Cloud. About 160 thousand light-years away, it's the largest, most violent star forming region known in the whole Local Group of galaxies.

APOD: 2024 May 8 Б Visualization: A Black Hole Accretion Disk
7.05.2024

What would it look like to circle a black hole? If the black hole was surrounded by a swirling disk of glowing and accreting gas, then the great gravity of the black hole would deflect light emitted by the disk to make it look very unusual. The featured animated video gives a visualization.

Phobos: Doomed Moon of Mars
18.08.2001

Mars, the red planet named for the Roman god of war, has two tiny moons, Phobos and Deimos, whose names are derived from the Greek for Fear and Panic. These Martian moons may well...