A Sonic Boom
4.05.2003

Many people have heard a sonic boom, but few have seen one. When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane cannot precede the plane, and so accumulate in a cone behind the plane.

Spiral Galaxy NGC 7742
26.07.2003

This might resemble a fried egg you've had for breakfast, but it's actually much larger. In fact, ringed by blue-tinted star forming regions and faintly visible spiral arms, the yolk-yellow center of this face-on spiral galaxy, NGC 7742, is about 3,000 light-years across.

MyCn18: An Hourglass Nebula
14.09.1997

The sands of time are running out for the central star of this hourglass-shaped planetary nebula. With its nuclear fuel exhausted, this brief, spectacular, closing phase of a Sun-like star's life occurs as its outer layers are ejected - its core becoming a cooling, fading white dwarf.

NGC 4314: A Nuclear Starburst Ring
15.06.1998

Is this old galaxy up to new tricks? The barred spiral galaxy NGC 4314 is billions of years old, but its appearance has changed markedly over just the past few millions of years. During that time, a nuclear ring of bright young stars has been evolving.

A Great Day For SOHO
15.10.1998

The last 10 days have been great days for SOHO, the space-based SOlar and Heliospheric Observatory. Contact was completely lost with this international research spacecraft over 3 months ago but recovery teams have reacquired control of SOHO and, beginning October 5th, have been successfully switching on its scientific instruments.

HUDF: Dawn of the Galaxies
29.09.2004

When did galaxies form? Faint red smudges identified on the deepest optical sky image ever taken may well be members of the first class of galaxies. Detailed inspection of the Hubble Ultra Deep Field...

Old Planetary Dust Disks Found by SST
19.10.2004

Why are some older stars surrounded by dust? Observations from the Spitzer Space Telescope by a team led by George Rieke (U. Arizona) were expected to show that young stars, on the order of one million years old, have large dust disks, while relatively older stars, between 10 and 100 million years old, have none.

A Map of Asteroid Vesta
20.08.2006

Vesta is a huge rock 500 kilometers across that orbits out past Mars. In 1997, the above map of Vesta created using the Hubble Space Telescope was released showing a rugged surface highlighted by a single crater spanning nearly the entire length of the asteroid.

Dust Storm on Planet Earth
3.03.2000

From low Earth orbit, NASA's SeaWIFS instrument records ocean color, tracking changes in our water world's climate and biosphere. But even an ocean planet can have dust storms. On February 26th, SeaWIFS...

NGC 4314: A Nuclear Starburst Ring
12.12.1999

Is this old galaxy up to new tricks? The barred spiral galaxy NGC 4314 is billions of years old, but its appearance has changed markedly over just the past few millions of years. During that time, a nuclear ring of bright young stars has been evolving.