The Mysterious Rings of Supernova 1987A
7.01.2007

What's causing those odd rings in supernova 1987A? In 1987, the brightest supernova in recent history occurred in the Large Magellanic Clouds. At the center of the picture is an object central to the remains of the violent stellar explosion.

Crescent Neptune and Triton
25.07.2021

Gliding silently through the outer Solar System, the Voyager 2 spacecraft camera captured Neptune and Triton together in crescent phase. The elegant picture of the gas giant planet and its cloudy moon was taken from behind just after closest approach in 1989.

The Millennium that Defined Earth
31.12.2000

When the second millennium began, people generally knew that the Earth was round, but few saw much of it beyond their local village. As the millennium progressed, humans mapped the continents, circumnavigated the globe, and determined the composition of the Earth.

One Small Step
21.09.1995

On July 20th, 1969, a human first set foot on the Moon. Pictured above is the first lunar footprint. The footprint and distinction of the first person to walk on the Moon belong to Neil Armstrong.

Mimas: Small Moon with A Big Crater
24.09.1995

Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters! In fact, if the impact had been much greater, it would have disrupted the entire satellite. The large crater has been named Herschel after the 1789 discoverer of Mimas, Sir William Herschel.

NGC 2440 Nucleus: The Hottest Star?
30.11.1995

In the center of the above photograph lies a star with one of the hottest surface temperatures yet confirmed. This bright white dwarf star's surface has been measured at greater than 200,000 degrees Celsius - more than 30 times hotter than that of our own Sun.

Summer at the South Pole
22.12.1995

December 22 marks the Winter Solstice - the beginning of winter in the Earth's northern hemisphere, and the first day of summer in the south! This view of Earth's southern hemisphere near the beginning of its summer was created using images from the Galileo spacecraft taken during the December 1990 flyby.

Uranus' Moon Ariel: Valley World
3.03.1996

What formed Ariel's valleys? This question presented itself when Voyager 2 passed this satellite of Uranus in January 1986. Speculation includes that heating caused by the ancient tides of Uranus caused moonquakes and massive shifting of the moon's surface.

Astro 1 In Orbit
4.05.1996

In December of 1990, the Space Shuttle Columbia carried an array of astronomical telescopes high above the Earth's obscuring atmosphere to observe the Universe at ultraviolet and x-ray wavelengths. The telescopes, known...

Black Holes and Galactic Centers
14.01.1997

Do all galaxies have black holes at their centers? Although not even a single galaxy has yet been proven to have a central black hole, the list of candidates has increased yet again. Recent...