Seven research efforts involving the University of Colorado at Boulder were among the top 100 science stories of the year selected by Discover Magazine — ideas and breakthroughs that are reshaping our understanding of the world, according to the publication.

CU-Boulder research was involved in the following top science stories cited by Discover for 2009:

• New planet-hunting efforts (No. 8)
• The MESSENGER mission to Mercury (28)
• Arctic warming (60)
• Water vapor jets on Enceladus, a moon of Saturn (67)
• Early bombardment of Earth by asteroids (77)
• The Large Hadron Collider (86)
• The Hubble Space Telescope repair mission (100)

Two of the top stories published in this month's issue were based entirely on CU-Boulder research.

The magazine highlighted work by Mark Serreze, CU-Boulder geography professor, and his team on dwindling Arctic sea ice and its outlook for the future. The research by Serreze, who also is director of CU-Boulder's National Snow and Ice Data Center, ranked as the 60th top science story by Discover for monitoring the loss of Arctic sea ice from 1979 to 2009.

The 77th ranked story featured the research effort by Oleg Abramov, research associate, and Stephen Mojzsis, professor in CU-Boulder's geological sciences department, on the massive bombardment of Earth nearly 4 billion years ago by asteroids as large as Kansas.

Five other top stories featured contributions by CU-Boulder scientists.

The eighth top story in Discover cited new technologies being used to spot planets orbiting other stars. One new tool, NASA's Kepler spacecraft that launched in 2009, is giving a huge boost to planetary scientists by scanning thousands of stars for evidence of periodic dips in starlight signaling transits of orbiting planets moving across star faces.

A team of students and professionals from CU-Boulder's LASP, led by Bill Possel, mission operations and data systems director, are operating the Kepler spacecraft from campus, working with Ball Aerospace and Technologies Corp. of Boulder.

Story No. 28 was a flyby of Mercury last September by NASA's MESSENGER spacecraft that discovered evidence of past volcanism and provided new findings about the planet's tenuous atmosphere. A team led by William McClintock of LASP, who led the development of an $8.7 million CU-Boulder instrument aboard MESSENGER, discovered widespread magnesium and imaged sodium and calcium, which also have been seen from Earth. The team found that atoms are blasted from the planet's surface by solar winds and are constantly replenishing the planet's atmosphere before drifting away into space.

The 67th top story involved three recent studies published in Nature on water vapor jets emanating from Saturn's tiny, icy moon Enceladus; Nicholas Schneider, professor in CU's Laboratory of Atmospheric and Space Physics, led one of those studies.

The Large Hadron Collider, story No. 86, was designed to send protons and charged atoms whizzing around a 17-mile underground loop in Europe at 11,000 times per second in an attempt to re-create the conditions immediately following the Big Bang. Some 15 CU-Boulder researchers are involved with the collider's Compact Muon Solenoid, or CMS, one of two massive particle detectors in the collider.

Rounding out the list of 100 stories: the 2009 Hubble Space Telescope repair mission, including installation of the new Wide Field Camera 3, which has a higher resolution and a more expanded field of view than previous Hubble cameras. A second instrument installed on the orbiting observatory during the mission was the Cosmic Origins Spectrograph, designed by a team led by CU-Boulder's James Green.