SUNSET: 
How To Identify Stony Meteorites in the Field
Ruben Garcia searches for meteorites with a meteorite cane.Ruben GarciaMeteorite identification in the field is one of the most difficult things for an aspiring meteorite hunter to learn. The skill is most certainly an acquired one. But once that skill is learned, a good meteorite hunter can easily spot a…
Surface Characteristics of Iron Meteorites
This iron meteorite was seen to fall in the Sikhote-Alin Mountains in eastern Russia in 1947. Even though it was picked up years after the fall and has started to oxidize, it still shows well-formed thumbprints (regmagylpts) and some remaining fusion crust.Geoffrey NotkinIron meteorites are generally easier to identify than…
Phoenix: Behind the Scenes
With the future of Martian exploration riding on NASA's Phoenix lander, mission scientists still find time to enjoy the experience.
Astronomical Sky Surveys
An artist's concept of the 8.4-meter Large Synoptic Survey Telescope (LSST), which should being scanning the sky in 2016.LSST Corp.Astronomers are scanning the sky with a variety of programs that collect gigabytes of data each night — and more are coming. The following links will take you were you can…
Watch the Sky From Chile
High above the clouds (and most of the Earth's atmosphere), from 19,000 feet (5,900 meters), the southern sky reveals its true majestic glory. Watch as the heavens rotate above the Chajnantor plateau high in the Chilean Atacama Desert.
A New Day in Precision Cosmology
The date of the Big Bang? The amount of dark matter? The nature of cosmic inflation? These things and more are refined by new results from the WMAP cosmology probe. Here's a full roundup.
Largest Optical Telescopes
Largest Optical Telescopes of Today & Tomorrow Name and location Primary-mirror aperture (meters) European Extremely Large Telescope (proposed) 42 Thirty Meter Telescope (proposed) 30 Giant Magellan Telescope (proposed) Cerro Las Campanas, Chile 24.5 Gran Telescopio Canarias (GTC) La Palma, Canary Islands 10.4 Keck Telescopes Mauna Kea, Hawaii 10.0 (×2) Southern…
The Challenge of Adaptive Optics
Adaptive-optics systems aim to improve the resolution of astronomical observations by compensating for the effects of air turbulence.
Stars and Paradise
The twin 10-meter telescopes of Keck Observatory are among the highlights atop Mauna Kea, Hawaii. To the left is the Japanese Subaru Observatory.W. M. Keck ObservatoryWhen most people think of Hawaii, they ponder volcanoes, luaus, hula dancers, and pineapples. But Hawaii also sports one of Earth's best vacation spots for…
The 2008 Eclipse and the Saros Cycle
The August 1, 2008, total eclipse is similar to a couple of significant past eclipses. Here's why.
Sky & Telescope's Satellite Calculator
Launch Sky & Telescope's new Satellite Tracker.
Simulating a Type Ia Supernova
In the July 2007 issue of Sky & Telescope (page 32), science writer David S. Stevenson describes some of the recent progress made by astronomers in figuring out what causes Type Ia supernovae. Most supernova explosions signal the deaths of short-lived massive stars, but Type Ia blasts come from old…
Images from Apogee's Alta U9000 CCD Camera
While processing the images Dennis di Cicco recorded during his review of the Apogee Alta U9000 CCD camera, I was most impressed by the high sensitivity of the KAF-09000 chip. The images presented here are some of my favorites. Each of these photographs were recorded through a 15 nanometer passband…
Transit of Luna
Click on image for a 2MB animation.NASAOn February 25th the Moon crossed the Sun in an unearthly annular eclipse — one that can never be seen from Earth. These ultraviolet images were taken by one of NASA’s two STEREO solar observatories, which were launched last October and are now watching…
Using Digital Imagery to Detect Earth's Penumbra
With a little help, you can see the first hint of the Earth's shadow — the penumbra — on the Moon's surface. Here's what you need to know.
A Killer Blast?
Click on image for a 1MB animated GIF.Brian Fields, Themis Athanassiadou, Scott Johnson, and NASA.A supernova popping off near Earth could spell big trouble for our biosphere. University of Illinois astronomer Brian Fields and two colleagues used a computer to simulate what would happen if a star 30 light-years away…
The Hyades Movie
Click above to watch the stars of the Hyades Cluster separate from the unrelated stars in Taurus.Anthony Brown In 1997 scientists associated with the Hipparcos satellite published a 3-D map of stars in the Hyades cluster. It was the first time that the structure of a star cluster had ever…
Galaxies in Collision
Animations of the Milky Way colliding with the Andromeda Galaxy