----- Original Message ----- From: Sunny To: Undisclosed-Recipient:; Sent: Friday, January 18, 2008 5:52 AM Subject: [zamanku] Spacecraft glimpses a new view of Mercury
http://www.theage.com.au/news/world/new-view-of-mercury/2008/01/17/1200419972483.html Spacecraft glimpses a new view of Mercury Advertisement Warren Leary, Washington January 18, 2008 THE Messenger spacecraft dashed past Mercury on Monday, getting a glance at the solar system's innermost planet, which it will eventually orbit for detailed studies. The robot spacecraft, the first to visit the planet in more than three decades, passed about 200 kilometres above Mercury's cratered surface before continuing on a path that is to bring it back three more times in the next three years before settling into orbit. "Everything went really well," Eric Finnegan, the Messenger systems engineer, said after the encounter. A faint signal reappeared on schedule after the craft emerged from behind Mercury after the close approach, he said. During the fly-by, Messenger was to take more than 1200 pictures of areas not previously photographed and make measurements of the planet's surface chemical composition, wispy atmosphere and gravitational field. "We expect many surprises," said Sean Solomon of the Carnegie Institution of Washington, the mission's lead investigator. Understanding Mercury's history is pivotal to studying the evolution of the inner solar system, he said. Messenger carried out the encounter on automatic pilot, having turned itself and its main antenna away from Earth on Sunday to get maximum protection from the sun behind its highly reflective sunshade. The craft is to contact Earth again on Tuesday, when it will begin sending back data from the fly-by, scientists said. The spacecraft, launched by NASA in August 2004, is only about halfway through a 7.9-billion-kilometre journey needed to manoeuvre it into orbit. The journey involves more than 15 trips around the sun, including flying by Earth once, passing Venus twice and three swings around Mercury before slipping into orbit in March 2011. "The complexity of this mission, with its numerous fly-bys and multitude of manoeuvres, requires close and constant attention," said Peter Bedini, project manager at the Johns Hopkins University applied physics laboratory, where the craft was designed and built and the mission is controlled. On Monday, Messenger streaked past Mercury at more than 25,000 km/h but a major goal of the encounter was to use the planet's gravity to slow the craft by 8000 km/h. Two more fly-bys in October this year and September 2009 will bleed off enough speed for the spacecraft to orbit the planet. Messenger - short for Mercury Surface, Space Environment, Geochemistry and Ranging - is the first spacecraft to visit the planet since NASA's Mariner 10 made three fly-bys from 1974 to 1975. Mariner 10 mapped 45% of the planet, leaving an entire hemisphere a mystery until now. Mercury, with a 4880-kilometre diameter, is only slightly larger than Earth's moon. NEW YORK TIMES ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.19.6/1230 - Release Date: 17/01/2008 16:59 [Non-text portions of this message have been removed]
