New revelations about Mercury’s volcanism, magnetic substorms and exosphere from MESSENGER

(July 16, 2010) — Analysis of data from MESSENGER's third and final flyby of Mercury in September 2009 has revealed evidence of younger volcanism on the innermost planet than previously recognized, new information about magnetic substorms, and the first observations of emission from an ionized species in Mercury's very thin atmosphere or exosphere. The results are reported in three papers published online on July 15 in the Science Express section of the website of Science magazine. "Every time we've encountered Mercury, we've discovered new phenomena," says MESSENGER principal investigator Sean Solomon, of Carnegie's Department of Terrestrial Magnetism. "We're learning that Mercury ... Read More

MESSENGER Spacecraft Reveals More Hidden Territory On Mercury

(Nov. 10, 2009) — A NASA spacecraft gliding over the battered surface of Mercury for the second time this year has revealed more previously unseen real estate on the innermost planet. The probe also has produced several science firsts and is returning hundreds of new photos and measurements of the planet's surface, atmosphere and magnetic field. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging, or MESSENGER, spacecraft flew by Mercury shortly after 4:40 a.m. EDT, on Oct. 6. It completed a critical gravity assist to keep it on course to orbit Mercury in 2011 and unveiled 30 percent of Mercury's ... Read More

MESSENGER Spacecraft Prepares For Final Pass By Mercury

(Sep. 28, 2009) — NASA's Mercury Surface, Space Environment, Geochemistry, and Ranging spacecraft known as MESSENGER will fly by Mercury for the third and final time on Sept. 29. The spacecraft will pass less than 142 miles above the planet's rocky surface for a final gravity assist that will enable it to enter Mercury's orbit in 2011. Determining the composition of Mercury's surface is a major goal of the orbital phase of the mission. The spacecraft already has imaged more than 90 percent of the planet's surface. The spacecraft's team will activate instruments during this flyby to view specific features ... Read More

Magnetic Tornadoes Could Liberate Mercury’s Tenuous Atmosphere

(June 2, 2009) — As the closest planet to the sun, Mercury is scorching hot, with daytime temperatures of more than 800 degrees Fahrenheit (approximately 450 degrees Celsius). It is also the smallest rocky planet, so its gravity is weak, only about 38 percent of Earth's. These conditions make it hard for the planet to hold on to its atmosphere, which is extremely thin, and invisible to the human eye. However, it can be seen by special instruments attached to telescopes and spacecraft like MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging). "Mercury's atmosphere is so thin, it would have ... Read More

Magnesium Detected In MESSENGER Flyby Of Mercury

(May 3, 2009) — NASA's MESSENGER spacecraft served up another curveball to a University of Colorado at Boulder team after a second flyby of the hot inner planet Oct. 6 detected magnesium -- an element created inside exploding stars and which is found in many medicine cabinets on Earth -- clumped in the tenuous atmosphere of the planet. Scientists had suspected magnesium would be present, but were surprised at its distribution and abundance, said Senior Research Associate William McClintock of CU-Boulder's Laboratory for Atmospheric and Space Physics. The discovery in the planet's wispy atmosphere, known as its exosphere, is one ... Read More

Messenger Spacecraft to Photograph Mercury

NASA scientists will get a bit of holiday cheer on Monday, as the Messenger spacecraft speeds toward its third encounter with Mercury and snaps about 1,500 pictures.By By KENNETH CHANG

THE AGE OF DISSONANCE; Blame the Messenger

Comment on astrological term 'Mercury in retrograde,' invoked by some as excuse for communication mixupsBy By BOB MORRIS

Mercury Will Become the Next Planet to Get Its Close-Up

Messenger spacecraft, which is set to launch on seven-year mission next week, will be first craft to orbit Mercury and conduct long-term study; scientists who designed Messenger developed craft able to withstand 700 degrees Fahrenheit to protect it from sun and channel away heat, while reducing reflectivity and radiation effects; mission described; Mercury is small rocky planet slightly larger than earth's moon and is nearest planet to sun; drawing; photosBy By WARREN E. LEARY

National Briefing | Science And Health: Messenger Spacecraft Begins Journey To Mercury

NASA's Messenger spacecraft begins five-billion-mile journey to MercuryBy By STEFANO S. COLEDAN (NYT)

New Planets Astound Astronomers in Speed and Distance

Among a batch of new planets, found by the Hubble telescope on a small patch of sky in Sagittarius, are as many as five that orbit their home stars in less than a day.By By DENNIS OVERBYE