|
|
|
|
|
Massive star's death and the dusty universe SPITZER SCIENCE CENTER RELEASE Posted: June 10, 2006 When the universe was only 700 million years old, some of its galaxies were already filled with lots of dust. But where did all of this dust come from? Astronomers using NASA's Spitzer Space Telescope think they may have found the source in type II supernovae, the violent explosions of the universe's most massive stars.
Using the space-based Spitzer and Hubble Space Telescopes and the ground-based Gemini North Telescope atop Mauna Kea in Hawaii, Dr. Ben Sugerman of the Space Telescope Science Institute in Baltimore, Md. and his colleagues found a significant amount of heated dust in the remains of a massive star called supernova SN 2003gd. The supernova remnant is located approximately 30 million light-years away in the spiral galaxy M74. Stars like the progenitor of supernova SN 2003gd have relatively short lives of just tens of millions of years. Since Sugerman's work shows supernovae produce copious amounts of dust, he believes the explosions could account for much of the dust in the early universe. His findings will be published in the June 8 issue of Science Express. "This discovery is interesting because it is finally showing that supernovae are significant contributors to dust formation, when evidence up to now has been inconclusive," said Sugerman. Because supernovae fade fairly quickly, scientists need very sensitive telescopes to study them even a few months after the initial explosions. Scientists have suspected that most supernovae do produce dust, but their ability to study this dust production in the past has been limited by technology. "People have suspected for 40 years that supernovae could be producers of dust, but the technology to confirm this has only recently become available," said Sugerman. "The advantage of using Spitzer is that we can actually see the warm dust as it forms." "Dust particles in space are the building blocks of comets, planets, and life, yet our knowledge of where this dust was made is still incomplete. These new observations show that supernovae can make a major contribution to enriching the dust content of the universe," said Dr. Michael Barlow of University College London in the United Kingdom. This research is part of a collaboration called the Survey for Evolution of Emission from Dust in Supernovae (SEEDS), which is led by Barlow. |
|
|
|
 |
|||||||||||||||||||||
A comprehensive series of press briefings for space shuttle Discovery's upcoming STS-121 begins with a program overview conference by Wayne Hale, NASA's manager of the shuttle program, and Kirk Shireman, the deputy program manager of the International Space Station. The two men discuss the significance of Discovery's mission to their respective programs. The briefing was held June 8 at the Johnson Space Center.
Dial-up: 
NASA officials unveil the plan to distribute work in the Constellation Program for robotic and human moon and Mars exploration. This address to agency employees on June 5 was given by Administrator Mike Griffin, Associate Administrator for the Exploration Systems Mission Directorate Scott Horowitz and Constellation Program Manager Jeff Hanley.
Following their announcement on the Exploration work assignments to the various NASA centers, Mike Griffin, Scott Horowitz and Jeff Hanley hold this news conference to answer reporter questions.
Space shuttle program manager Wayne Hale and launch director Mike Leinbach hold this news conference May 31 from Kennedy Space Center to offer a status report on STS-121 mission preparations. The briefing was held at the conclusion of the debris verification review, which examined the external fuel tank and threats to the shuttle from impacts during launch.
NASA created its Tracking and Data Relay Satellite (TDRS) system to serve as a constellation of orbiting spacecraft that would replace the costly ground tracking stations scattered around the globe for communications with space shuttles and other satellites. Space shuttle Discovery's STS-29 mission in March 1989 launched the massive TDRS-D craft. This post-flight film narrated by the crew shows the deployment, the astronauts running a series of medical tests and the monitoring of a student-developed chicken embryo experiment.
The Boeing Delta 4 rocket launches from pad 37B at Cape Canaveral Air Force Station with the GOES-N spacecraft, beginning a new era in weather observing for the Americas.