SUNSET: 
Solar Impact: The Sun-Earth Connection
Solar physicist Judith Lean (U.S. Naval Research Laboratory) studies how solar radiation affects Earth's weather and climate.Judith LeanAstronomers have long known that sunspot numbers vary over a cycle that averages about 11 years. But do these cycles influence Earth's climate? And what about the longer term? Could the measured global…
What's a Planet?
David Grinspoon is Curator of Astrobiology at the Denver Museum of Nature & Science.David GrinspoonWhat makes a planet a planet? In 2006 the International Astronomical Union (IAU) adopted a definition of "planet" that from its outset, sparked controversy. The IAU defined a planet to be: A celestial body that (a)…
Is Dark Energy Bad for Astronomy?
In 2007 Simon White (Max Planck Institute for Astrophysics, Germany) wrote a controversial paper titled “Fundamentalist Physics: Why Dark Energy Is Bad for Astronomy.” Let us know what you think about this subject.
The Mystery of Dark Energy: An Interview with Richard Panek
Robert Naeye, editor in chief of Sky & Telescope, interviews Richard Panek, author of the Dark Energy feature in the February 2009 issue of S&T.
Galaxy Archaeology with Amateurs
Using off-the-shelf equipment, R. Jay GaBany was a key team member in the discovery of galaxy star streams surrounding NGC 5907.R. Jay GaBanyAstronomers investigating the origin and evolution of galaxies have discovered clues to these fundamental studies with the help of an unlikely source: backyard astrophotographers. David Martinez-Delgado of the…
The Hunt for Alien Earths
Astronomers are building the tools to find extrasolar planets of ever-lower masses — from giants like Jupiter down to exo-Neptunes and even super-Earths. Soon they'll be finding planets as small as our own. The ultimate goal is to examine these for signs of life. Exoplanet researchers Sara Seager and Dimitar Sasselov, featured in the January 2009 Sky & Telescope, tell about this exciting work.
Amateur Asteroid Discoveries
Amateur Paul Mortfield shares his experiences looking for asteroids, variable stars, and other changes in the night sky. He describes his techniques in the December issue of S&T.
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…
