NASA scientists said 3-D images of the sun taken by the Solar Terrestrial Relations Observatory are expanding our understanding of solar physics. The images, to be released Monday on the Internet, television and at museums, are also expected to help improve space weather forecasting.
On Feb. 25, 2007, NASA scientists were calibrating some cameras aboard the STEREO-B spacecraft and they pointed the instruments at the sun. The purpose of the experiment was to measure the 'dark current' of STEREO-B's CCD detectors. The idea is familiar to amateur astronomers: Point your telescope at something black and see how much 'dark current' trickles out of the CCD. Later, when real astrophotography is taking place, the dark current is subtracted to improve the image.
On Feb. 25, 2007 there was a transit of the Moon across the face of the Sun - but it could not be seen from Earth. This sight was visible only from the STEREO-B spacecraft in its orbit about the sun, trailing behind the Earth. NASA's STEREO mission consists of two spacecraft launched in October, 2006 to study solar storms. The transit starts at 1:56 am EST and continued for 12 hours until 1:57 pm EST. STEREO-B is currently about 1 million miles from the Earth, 4.4 times farther away from the Moon than we are on Earth. As the result, the Moon will appear 4.4 times smaller than what we are used to. This is still, however, much larger than, say, the planet Venus appeared when it transited the Sun as seen from Earth in 2004.
Twin Nasa spacecraft have returned panoramic images that will help scientists to study solar explosions capable of causing havoc on Earth. The Stereo orbiters, which are nearing their final positions, will study violent solar eruptions known as Coronal Mass Ejections (CMEs). CMEs hurl energetic particles at Earth that can disrupt power grids and satellite communications. Stereo will give scientists information they need to forecast "space weather". The new panoramic views, which stretch from the Sun to the Earth, are created by combining images from a suite of telescopes onboard the two spacecraft. Their data will allow scientists to track "solar fronts".
Loops of highly charged particles burst from an active region on the Sun’s surface in this image, taken on December 4, 2006. Among the first images taken by STEREO’s SECCHI/Extreme Ultraviolet Imaging Telescope, the image shows the Sun’s roiling surface and atmosphere at temperatures around one million Kelvin (1.8 million degrees Fahrenheit). The ultraviolet light in this range is not typically visible to the human eye, so it is represented here in blue.
To understand how solar storms travel through the solar systems, scientists need a three-dimensional view of the storms. This view will be provided by the STEREO telescopes launched on October 25, 2006. STEREO consists of Sun observation systems orbiting the Sun in front of and behind the Earth. Just as two separate eyes give humans a three-dimensional view of the world, the views provided by each STEREO system can be combined to provide a three-dimensional view of the Sun. Though the first STEREO images were taken in early December, the two systems won’t be in position to give three dimensional images until April 2007.
NASA's twin Solar Terrestrial Relations Observatories (STEREO) sent back their first images of the sun this week and with them a view into the sun's mounting activity. After a successful launch on Oct. 25 from Cape Canaveral Air Force Station, Fla., STEREO spent the first few minutes separating from its stacked configuration aboard the single Delta II rocket. Shortly afterwards, mission operations personnel at The Johns Hopkins University Applied Physics Laboratory, (APL) Laurel, Md., monitored the two observatories as they travelled in an elliptical orbit from a point close to Earth to one extending just beyond the moon.
On October 25, 2006, two space probes from the STEREO mission were launched from the American space centre at Cape Canaveral, ushering in a new era in solar research. The Max Planck Institute for Solar System Research (MPS) in Katlenburg-Lindau is playing a major part in representing Germany on this international mission. Thanks to new 3-dimensional observation technology, the project is intended to improve our understanding of the processes on the sun’s surface and their effect on the earth’s atmosphere ("space weather").