Abell 370: Galaxy Cluster Gravitational Lens
28.08.2016

What is that strange arc? While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. Although curious, one initial response was to avoid commenting on the arc because nothing like it had ever been noted before.

A GRB 000301C Symphony
3.06.2001

Last March, telescopic instruments in Earth and space tracked a tremendous explosion that occurred across the universe. A nearly unprecedented symphony of international observations began abruptly on 2000 March 1 when Earth-orbiting RXTE, Sun-orbiting Ulysses, and asteroid-orbiting NEAR all detected a 10-second burst of high-frequency gamma radiation. Within 48 hours astronomers

A Distant Cluster of Galaxies
14.01.1996

Every bright object in this 1994 photograph by the Hubble Space Telescope is a galaxy. Oddly - most of the objects are spiral galaxies. This rich cluster of galaxies, named CL 0939+4713, is almost half way across the visible universe.

Lightning on Jupiter
12.05.1997

Does lightning occur only on Earth? Spacecraft in our Solar System have detected radio signals consistent with lightning on other planets, including Venus, Jupiter, Saturn, Uranus, and Neptune. In the above photograph, optical flashes from Jupiter were photographed recently by the Galileo orbiter. Each of the circled dots indicates lightning.

NGC 1365: Barred Spiral Galaxy
8.10.1999

NGC 1365 is a giant barred spiral galaxy about 200,000 light-years in diameter and 60 million light-years distant in the southern constellation Fornax. These three recently released images offer views of this majestic island universe in visible and infrared light.

Jupiter's Moon Amalthea
3.11.1995

Amalthea is Jupiter's fifth largest moon, much smaller than the four Galilean satellites Io, Europa, Ganymede, and Callisto. The orbit of Amalthea is inside of these moons, and with its long axis always pointing toward Jupiter. It's dark surface color is probably due to sulfur being expelled from Io.

Cancri 55 e: Climate Patterns on a Lava World
5.04.2016

Why might you want to visit super-earth Cancri 55 e? Its extremely hot climate would be a deterrent, as mornings on this world might bring fresh lava flows. Discovered in 2004, the planet Cancri 55 e has twice the diameter of our Earth and about 10 times Earth's mass.

Our Solar System from Voyager
19.08.1995

After taking its spectacular pictures of the outer solar system planets, Voyager 1 looked back at six planets from the inner solar system. Here Venus, Earth, Jupiter, Saturn, Uranus, and Neptune, were all visible across the sky.

Sizzling Io
6.07.1998

What's cooking on Io? This active moon of Jupiter is marked with volcanoes spewing lava that is now known to be hotter than any lava on Earth. Above is the highest resolution color-enhanced image yet composed of the most active surface in our Solar System. Features as small as three kilometers are visible.

Arp 230: Two Spirals in One?
31.08.1997

Is this one galaxy or two? Analysis of Arp 230 has shown evidence that this seemingly single spiral galaxy is actually the result of the recent collision of two spiral galaxies. The slow motion collision took place over about 100 million years and induced a burst of star formation that has begun to subside.