|
|
|
|
|
STEREO previews improved solar storm tracking NASA NEWS RELEASE Posted: March 1, 2007 For the first time, scientists can track solar storms from the sun to Earth using the latest images from NASA's twin STEREO spacecraft. "The new view from the STEREO spacecraft will greatly improve our ability to forecast the arrival time of severe space weather," said Dr. Russell Howard of the Naval Research Laboratory, Washington, the Principal Investigator of STEREO's Sun-Earth Connection Coronal and Heliospheric Investigation (SECCHI). "Previous imagery did not show the front of a solar disturbance as it traveled toward Earth, so we had to make estimates of when the storm would arrive. These estimates were uncertain by a day or so. With STEREO, we can track the front from the sun all the way to Earth, and forecast its arrival within a couple hours."
The new panoramic views are created by combining images from the SECCHI suite of telescopes on both spacecraft. They allow scientists to track a type of solar disturbance called a Coronal Mass Ejection (CME) from its birth at the sun towards Earth. CMEs are violent eruptions of electrically charged gas, called plasma, from the sun's atmosphere. A CME cloud can contain billions of tons of plasma and move at a million miles per hour. As the CME cloud plows through the solar system, it slams into the slower solar wind, a thin stream of plasma constantly blowing from the sun. The collision with the solar wind generates a shock that accelerates electrically charged particles in the solar wind, causing radiation storms that can disrupt sensitive electronics on satellites and cause cancer in unshielded astronauts. A CME cloud is also laced with magnetic fields and CMEs directed our way smash into Earth's magnetic field. If the CME magnetic fields have the proper orientation, they dump energy and particles into Earth's magnetic field, causing magnetic storms that can overload power line equipment. Satellite and utility operators can take precautions to minimize CME damage, but they need an accurate forecast of when the CME will arrive.
As good as these images are, they are about to get even better. The two observatories will orbit the sun, one slightly ahead of Earth and one slightly behind, separating from each other by approximately 45 degrees per year. Just as the slight offset between your eyes provides you with depth perception, this separation of the spacecraft will allow them to take 3-D images and particle measurements of the sun. Scientists will use the 3-D views to discover new details about the structure of CME clouds, and to see how that structure evolves as the clouds move through space. The first 3-D views are expected in April. STEREO is the third mission in NASA's Solar Terrestrial Probes Program. STEREO is sponsored by NASA's Science Mission Directorate, Washington, D.C. The Goddard Science and Exploration Directorate manages the mission, instruments, and science center. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., designed and built the spacecraft and is operating them for NASA during the mission. The STEREO instruments were designed and built by scientific institutions in the US, UK, France, Germany, Belgium, Netherlands, and Switzerland. |
|
|
|
 |
||||||||||||||||||||||
This U.S. Senate space subcommittee hearing to examine NASA's proposed Fiscal Year 2008 budget features testimony from NASA Administrator Mike Griffin on February 28.
Launch of space shuttle Atlantis is postponed after golf ball-sized hail from a severe storm damaged the foam insulation on the external fuel tank. NASA announces the delay and plans to return the shuttle to the Vehicle Assembly Building for repairs.
Spacewalking astronauts on the December 2006 flight of shuttle Discovery performed a delicate re-wiring of the International Space Station's electrical system and retracted a stubborn solar array wing. The work accomplished critical steps in preparing the station to power the upcoming international science laboratory modules. Some members of the STS-116 crew narrate the highlights of the mission in this post-flight film.
Shuttle Endeavour's visit to the space station in June 2002 brought up the Expedition 5 long-duration resident crew, a load of supplies and the Mobile Base System to serve as the platform for moving the station's robotic arm up and down the truss backbone. The shuttle crew also performed some surgery on the robot arm by replacing a failed joint. The crew narrates the highlights of STS-111 in this post-flight film.
The United Launch Alliance Delta 2 rocket roared away from Cape Canaveral Saturday carrying a quintet of NASA probes that seek to understand the physics behind auroral displays.
The STS-117 astronauts meet the press during the traditional pre-flight news conference held at the Johnson Space Center a month prior to launch. The six-person crew will deliver and activate a solar-power module for the International Space Station.
After a six-hour trip along the three-and-a-half-mile crawlerway from the Vehicle Assembly Building, space shuttle Atlantis arrives at launch pad 39A for the STS-117 mission.
Space shuttle Atlantis emerges from its processing hangar at dawn February 7 for the short trip to the Vehicle Assembly Building at Kennedy Space Center's Complex 39.
This documentary takes a look at the technical aspects of Project Mercury, including development of the capsule and the pioneering first manned flights of America's space program.
The voyage of Apollo 15 took man to the Hadley Rille area of the moon. Astronauts Dave Scott and Jim Irwin explored the region using a lunar rover, while Al Worden remained in orbit conducting observations. "Apollo 15: In the Mountains of the Moon" is a NASA film looking back at the 1971 flight.
Skylab, America's first space station, began with crippling problems created by an incident during its May 1973 launch. High temperatures and low power conditions aboard the orbital workshop forced engineers to devise corrective measures quickly. Astronauts Pete Conrad, Paul Weitz and Joe Kerwin flew to the station and implemented the repairs, rescuing the spacecraft's mission. This film tells the story of Skylab's first 40 days in space.
