2009 Science News of the Year: Atom & Cosmos

4:57pm, December 18, 2009
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A post-crash plume kicked up from the moon contained vapor and ice. NASA crashed an unmanned spacecraft into the lunar surface on October 9 in order to analyze the resulting debris for signs of water. Image Credit: NASA Water on the moon
The moon isn’t bone dry: Although planetary scientists had suspected as much for years, recent studies show that the surface is surprisingly dewy and the interior contains more water than previous analyses had indicated (SN: 10/24/09, p. 10). A spacecraft that NASA deliberately crashed into a permanently shadowed crater at the moon’s south pole as part of the LCROSS mission also dredged up a plume containing water vapor, proof that the crater housed a reservoir of water ice (SN Online: 11/13/09). The discoveries may make it easier for humans to colonize the moon, using lunar water as a natural resource. Water’s presence could also force scientists to reexamine a long-standing assumption about the moon’s origin. According to the leading model, the moon formed when a Mars-sized impactor smacked into the young Earth. However, many researchers had thought that any water would have been vaporized by the high temperatures generated during such a cataclysm.

Fresh view
Astronauts transform the Hubble Space Telescope into a new and improved observatory, which by September results in a series of new images for astronomers (SN Online: 5/19/09; SN: 9/26/09, p. 7).

Young heavyweights
Peering into the centers of five of the youngest galaxy clusters known in the universe, astronomers find several full-grown, massive adults among the myriad of toddlers. The discovery could call into question the leading theory of galaxy formation (SN: 4/25/09, p. 5).

Extra pounds
The biggest supermassive black holes may be two to four times heavier than previously thought (SN: 7/4/09, p. 5).

Possible WIMPs
Researchers working on an underground experiment to search for dark matter, the invisible material believed to make up at least 80 percent of the mass of the universe, announce the possible detection of a dark matter particle called a WIMP (SN: 1/2/10, p. 8).

Brine on Mars
A surprisingly high concentration of perchlorate salts in the Martian polar soil could mean that shallow, briny reserves of water lie just below much of the planet’s surface (SN: 4/11/09, p. 12).

Largest planetary ring
A newly discovered planetary ring circling Saturn stretches more than 24 million kilometers across (SN: 11/7/09, p. 8).

LHC sets record
The Large Hadron Collider becomes the world’s highest-energy particle accelerator, revving up each of its twin proton beams to energies of 1.18 trillion electron volts (SN Online: 11/30/09).

An ironic find
The Pierre Auger Observatory discovers that some of the highest-energy cosmic rays could be iron nuclei rather than protons (SN: 7/18/09, p. 8). And a new generation of telescopes traces gamma rays to gain support for the theory that supernovas are the source of some cosmic rays (SN: 12/5/09, p. 8).

Solar system’s ribbon
The first global map of the solar system reveals that neutral atoms are densely packed in a narrow ribbon around the system’s edge, a structure that current models don’t explain (SN: 11/21/09, p. 15).

Mercury times three
In three flybys, MESSENGER snaps portraits of portions of Mercury that had never been imaged close-up and acquires new details about the planet’s magnetic field and geology (SN: 1/26/08, p. 51; SN Online: 4/30/09; SN: 10/24/09, p. 10).

Whiff of life
Seasonal plumes of methane discovered on Mars might be a sign of microscopic life beneath the surface (SN: 2/14/09, p. 10).

Stormy weather on Mars
Planetary scientists find the first evidence of lightning on Mars (SN: 7/18/09, p. 8).

A Japanese mission provides the first gravity map of the moon’s hidden half (highs in red and lows in blue, above), quantifying the asymmetry between the moon’s nearside and farside (SN: 3/14/09, p. 9).

Planetary treasure chest
The discovery of 32 additional planets beyond the solar system brings the exoplanet tally to more than 400, and a team of astronomers concludes that about half of all sunlike stars host lightweight planets less than three times Neptune’s mass (SN: 11/21/09, p. 14). Results of a new search technique also suggest that a trove of previously unknown exoplanets — perhaps as many as 100 — await discovery in a vast archive of images taken by the Hubble Space Telescope (SN Online: 2/27/09).

Antimatter signature
The Fermi Gamma-ray Space Telescope finds evidence of positrons in lightning storms on Earth (SN: 12/5/09, p. 9).

Shrinking dimensions
The length of any hidden extra dimension may not exceed 3 micrometers, a new study finds (SN: 8/1/09, p. 7).

Revving up particles
Newly recorded gamma rays from a microquasar may reveal how the black holes or neutron stars that power such cosmic beasts can accelerate particles to enormous energies (SN: 12/19/09, p. 12).

Going the distance
Astronomers find what appears to be a bounty of the most remote galaxies known, hailing from a time when the universe was less than a billion years old (SN: 10/10/09, p. 8).

Flying hazards
The number of car-to-house–sized space rocks whizzing through Earth’s neighborhood is about 10 times higher than ground-based surveys report (SN Online: 9/4/09).

Primordial partners
At least 5 percent and as many as 50 percent of the first stars in the universe were born in pairs, a new simulation suggests (SN: 8/1/09, p. 7).

Space collision
Two large satellites — a functioning U.S. device and a nonoperational Russian instrument — collide in orbit over Siberia, creating a swarm of some 600 chunks of debris (SN Online: 2/12/09).

Weighty star
The star that exploded as SN 2007bi had an estimated mass of 200 times the sun’s, making the star heavier than any known in the Milky Way and challenging theories of stellar evolution (SN Online: 12/2/09).

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