What are Comet Tails Made Of?
26.03.1996

The tail of comet Hyakutake, visible in this recent color image, is composed of dust and gas driven off the icy comet nucleus by the Sun's heat and blown away by the solar wind. Bathed in solar ultraviolet light, the gas molecules break down and are excited, producing a characteristic glow.

X Rays From Tycho s Supernova Remnant
12.09.2002

In 1572, Danish astronomer Tycho Brahe recorded the sudden appearance of a bright new star in the constellation Cassiopeia. The new star faded from view over a period of months and is believed to have been a supernova, one of the last stellar explosions seen in our Milky Way galaxy.

Titan from Cassini in Infrared
6.07.2004

Could life exist under the smog of Titan? If not, what is creating all of the methane? To help answer these questions, the largest and most mysterious moon of Saturn got a quick first look from the Cassini robot spacecraft soon after entering orbit around the giant planet last week.

MESSENGER s Last Day on Mercury
1.05.2015

The first to orbit Mercury, the MESSENGER spacecraft came to rest on this region of Mercury's surface yesterday. Constructed from MESSENGER image and laser altimeter data, the scene looks north over the northeastern rim of the broad, lava filled Shakespeare basin.

Fresh Tiger Stripes on Saturns Enceladus
27.04.2020

How will humanity first learn of extraterrestrial life? One possibility is to find it under the icy surface of Saturn's moon Enceladus. A reason to think that life may exist there are long features -- dubbed tiger stripes -- that are known to be spewing ice from the moon's icy interior into space.

Distant Galaxies in Radio Vision
8.02.2001

Radio waves, like visible light, are electromagnetic radiation and radio telescopes can "see" -- their signals translated into radio images of the cosmos. While individually even the largest radio telescopes have very blurry vision compared to their optical counterparts, networks of radio telescopes can combine signals to produce sharper pictures.

Two Tails of Comet Lulin
25.02.2009

Go outside tonight and see Comet Lulin. From a dark location, you should need only a good star map and admirable perseverance -- although wide-field binoculars might help. Yesterday, Comet Lulin passed its closest to Earth, so that the comet will remain near its brightest over the next few days.

W5: Pillars of Star Formation
20.11.2011

How do stars form? A study of star forming region W5 by the sun-orbiting Spitzer Space Telescope provides clear clues by recording that massive stars near the center of empty cavities are older than stars near the edges.

Fox Fur, Unicorn, and Christmas Tree
26.12.2020

Clouds of glowing hydrogen gas fill this colorful skyscape in the faint but fanciful constellation Monoceros, the Unicorn. A star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust...

Stars and Dust Across Corona Australis
6.08.2021

Cosmic dust clouds cross a rich field of stars in this telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Less than 500 light-years away the dust clouds effectively block light from more distant background stars in the Milky Way.