SUNSET: 
Astronomy Day 2004 Efforts Lauded
This year's celebration of Astronomy Day involved hundreds of organizations around the world and drew huge crowds.
Wildfires Threaten Arizona Observatories
A lightning-triggered fire raged up the slopes of Mount Graham and has come within a mile of the unfinished Large Binocular Telescope.
Cassini Peeks at Titan
Even when seen from 340,000 kilometers away, Saturn's giant moon has teased Cassini-Huygens scientists by revealing complex, mysterious surface features.
Saturn's Magnetic Mysteries
The ringed planet has more than a pretty face: early results from Cassini-Huygens have uncovered strange goings-on in the giant elecctromagnetic bubble that surrounds it.
Science Teams Await Leonid Storm
Researchers worldwide are looking forward to the new knowledge that they hope to gain from intensive studies of the Leonids' "last hurrah."
Spacecraft Readies for Risky Comet Dash
Concerns about camera pointing and fuel reserves will make the Deep Space 1 encounter with Comet Borrelly a risky proposition.Courtesy JPL and Spectrum Astro. The Deep Space 1 probe was never designed to chase comets. It has no shielding to protect its delicate systems from a pummeling of hypersonic dust.…
Eros's Puzzling Surface
Scientists are beginning to understand the complex asteroid's surface.
A Hit-and-Miss Annular Eclipse
Only a lucky few captured Friday's annular eclipse on film. Observing from near the eclipse's southern limit at Herradura Beach on Costa Rica's Pacific coast, Kelly Beatty recorded a cloud-laced view (left) using an Orion 90-mm f/13.9 Maksutov-Cassegrain. Just 7 km farther north, Paul Maley outraced the clouds to snare…
A Comet's Brush with the Sun
The SOHO spacecraft watched as a comet swung past the Sun.
Jupiter's Shrinking Red Spot
Compare the size (and color) of Jupiter's Great Red Spot as drawn by Thomas Gwyn Elger in November 1881 (left) and as imaged by Texas amateur Ed Grafton (right) 120 years later. South is up. Telescopic observers from the 19th century may not have had the technological wizardry available to…
Wrong-Way Blobs Sink Toward Sun
An enormous cloud of ionized gas plunges toward the Sun over three hours. The cloud becomes evident by electronically subtracting one frame from another taken some minutes later. To record such faint features, the Sun itself (yellow disks) must be hidden behind an occulting mask.Courtesy LASCO consortium, ESA, and NASA.…
Killer Asteroids: The Count Rises
This projection of the celestial sphere shows the sky coverage recorded by the 1-meter LINEAR telescope over three years. Bright yellow corresponds to an accumulated depth (faintness limit) of magnitude 20.8. In star-dense areas of the Milky Way (dark swath at right) and near the local horizon the survey probed…
Arecibo Radar Gets 11th-Hour Reprieve
The 305-meter (1,000-foot) radio telescope near Arecibo, Puerto Rico, has been used for radar probing of solar-system objects since the early 1960s. The facility underwent a $27 million upgrade in the mid-1990s.Photograph by David Parker (Science Photo Library); courtesy NAIC/Arecibo Observatory Facing tight budgets for its space-science activities, last week…
Was Mars All Wet?
NASA artist Greg Shirah depicts Mars as it might have looked some 4 billion years ago, with much of its northern hemisphere submerged under water.Courtesy NASA/Goddard Space Flight Center. Future astronauts roaming the surface of Mars will be hard-pressed to find sources of water, but the red planet was not…
A Probe for Pluto
With luck and another $260 million in funding, the New Horizons spacecraft will be skimming past distant, enigmatic Pluto (foreground) and its moon, Charon, 15 years from now. Selected by NASA last week, the spacecraft features four instruments, a plutonium-fueled powerplant, and a radio dish 2.5 meters (8 feet) across.Courtesy…
Comet Borrelly: Black and Bent
Deep Space 1 took this picture of Comet Borrelly's nucleus from 3,400 kilometers away. Astronomers now believe that Borrelly is the darkest object ever seen in the solar system.Courtesy NASA/JPL. In the two months since NASA’s Deep Space 1 craft zipped past the nucleus of Comet 15P/Borrelly, mission scientists have…
Mars's Bumpy Magnetism
A three-dimensional portrayal of Mars, as seen from the Sun, shows how magnetized regions of the planet's crust create electromagnetic 'bubbles' that extend hundreds of kilometers into the atmosphere.Courtesy David A. Brain (University of Colorado). In its infancy, Mars must have had a churning, conductive core and a magnetic field…
NASA Pulls Plug on 28-Year-Old Spacecraft
The Interplanetary Monitoring Platform (IMP) 8 spacecraft has radioed solar-wind conditions to Earth since 1973. The drum-shaped craft weighs 371 kilograms.Courtesy NASA/Goddard Space Flight Center. Bowing to pressure from NASA Headquarters to cut costs, a space-science review panel has recommended that the agency cease communications with an ancient, virtually unknown…
How Hot Can Venus Get?
Wind-sculpted details in the dense, sulfuric-acid clouds of Venus are accentuated in this ultraviolet image acquired by the Pioneer Venus Orbiter in February 1979.Courtesy NASA/Ames Research Center. The planet Venus is a textbook case of greenhouse warming run amok. Sunlight filters down through the planet's dense, cloud-choked atmosphere, where the…
