Lockheed Martin
Instruments Study Dynamic Solar Activity on New Sun Missions
(18 June 2007) Fresh insights into
long-standing solar mysteries and the first 3-D views of the Sun have been made
possible by Lockheed Martin space instruments on two new Sun-watching space
missions.
Hinode, an international co-operative mission, and
NASA's Solar Terrestrial Relations Observatory (STEREO) are providing solar
physicists a treasure trove of new data on the roiling turbulent nuclear
furnace at the centre of our solar system.
The primary scientific goal
of the Hinode mission, launched on Sept. 23, 2006, is to observe how changes in
the magnetic field at the Sun's surface propagate through the different higher
layers of the solar atmosphere. A torrent of new images show the Sun's magnetic
field to be far more chaotic and energetic than previously
believed.
"Hinode images are revealing irrefutable evidence for the
presence of turbulence driven processes that are bringing magnetic fields, on
all scales, to the Sun's surface, resulting in an extremely dynamic
chromosphere or gaseous envelope around the Sun," said Dr. Alan Title, solar
physicist at the Lockheed Martin Advanced Technology Center (ATC) in Palo Alto,
Calif. "We've known for some time that the solar interior is constantly ringing
like a bell. We're now learning that the enormous cacophony is leaking out
through the magnetic fields and the acoustic waves are causing tremendous
heating in the Sun's atmosphere."
A suite of instruments on Hinode,
called the Focal Plane Package (FPP) - designed and built at the Solar and
Astrophysics Laboratory of the ATC - is providing the high-resolution optical
measurements that show connections between changes in the Sun's magnetic field
and features of the solar atmosphere, both steady state - like coronal heating
- or transient - like flares and coronal mass ejections. The FPP resides on
Hinode's Solar Optical Telescope, the largest solar optical telescope ever to
be flown in space. It can to resolve features on the surface of the Sun just 90
mi. across.
Hinode, Japanese for "sunrise," is a Japanese mission,
developed and launched by Institute of Space and Astronautical Science and the
Japanese Aerospace Exploration Agency, in collaboration with the National
Astronomy Observatory of Japan. International partners include NASA, the
Science and Technology Facilities Council of the UK and the European Space
Agency. It is the second mission in the Solar Terrestrial Probes Program within
the Heliophysics Division of NASA's Science Mission Directorate, and follow-on
to the successful Japanese Yohkoh mission.
NASA's STEREO mission focused
a new pair of eyes on the Sun, as two spacecraft with identical instruments
were launched on October 25, 2006. The two spacecraft are on different
trajectories, to study the most energetic events on the surface and in the
lower atmosphere of the Sun, and their travel through interplanetary
space.
Data from spacecraft instruments are allowing scientists to
construct the first ever three-dimensional views of the Sun, providing a new
perspective on Coronal Mass Ejections (CMEs). CMEs are violent explosions on
the surface of the Sun that can propel up to 10 billion tons of the Sun's
atmosphere - at a million miles an hour - out through the corona and into
space.
The ATC-built Extreme Ultraviolet Imager (EUVI) instrument is one
element of an instrument suite on each STEREO spacecraft called SECCHI - the
Sun-Earth Connection Coronal and Heliospheric Investigation. SECCHI comprises a
suite of telescopes, including three white light coronagraphs and
EUVI.
"These first 3-D images are magnificent, and just a taste of
wonderful things to come! There is enormous satisfaction in seeing our years of
effort bear fruit. We've been studying CMEs for a long time, but SECCHI is
offering us new insight into the structure and evolution of the solar corona in
three dimensions, while EUVI focuses specifically on the initiation and early
evolution of CMEs," said Dr. James Lemen, Lockheed Martin co-investigator on
SECCHI. "EUVI and the other instruments on SECCHI are allowing us for the first
time to follow the propagation of these events through the corona, out into
interplanetary space and all the way to Earth, giving us a comprehensive view
of these enormous phenomena."
Coronal mass ejections, which are often
associated with solar flares, can take several days to reach the Earth. Fast,
powerful ejections give rise to geomagnetic storms, which can disrupt radio
transmissions and induce large currents in power transmission lines and oil
pipelines. They have resulted in large-scale failures of the North American
power grid and greatly increased pipeline erosion. CMEs also can generate
spectacular auroras in Earth's polar skies, but can disrupt spacecraft and be
extremely hazardous to astronauts. Seeing CMEs in 3-D will allow scientists to
discern the cloud front of these enormous detonations and improve predicted
arrival times at Earth by an order of magnitude or more.
The complex
physics of the solar atmosphere will also be more easily understood as
scientists can now view stereoscopic images of solar features and structures
and determine which are in front and which behind. The precise flow of matter
and energy as it propagates outward from the solar surface will be much
clearer.
NASA Goddard Space Flight Center in Greenbelt, Md. manages the
STEREO mission. The Johns Hopkins University Applied Physics Laboratory in
Laurel, Md. designed and built the spacecraft. The laboratory maintains command
and control of the observatories throughout the mission, while NASA tracks and
receives the data, determines the orbit of the satellites, and co-ordinates
science results.
The Solar and Astrophysics Laboratory at the ATC has a
43-year-long heritage of spaceborne solar instruments including the Soft X-ray
Telescope on the Japanese Yohkoh satellite, the Michelson Doppler Imager on the
ESA/NASA Solar and Heliospheric Observatory, the solar telescope on NASA's
Transition Region and Coronal Explorer and the Solar X-ray Imager on the GOES-N
environmental satellite. The laboratory also conducts basic research into
understanding and predicting space weather and the behavior of the Sun
including its impacts on Earth and climate. The ATC is also designing and
building two instruments for NASA's next Sun mission, the Solar Dynamics
Observatory, slated for launch in 2008.
The ATC is the research and
development organisation of Lockheed Martin Space Systems Company (LMSSC).
LMSSC is a major operating unit of Lockheed Martin Corporation, and designs,
develops, tests, manufactures and operates a full spectrum of
advanced-technology systems for national security, civil and commercial
customers. Chief products include human space flight systems; a full range of
remote sensing, navigation, meteorological and communications satellites and
instruments; space observatories and interplanetary spacecraft; laser radar;
fleet ballistic missiles; and missile defence systems.
Headquartered in
Bethesda, Md., Lockheed Martin employs about 140,000 people world-wide and is
principally engaged in the research, design, development, manufacture,
integration and sustainment of advanced technology systems, products and
services. The corporation reported 2006 sales of US$ 39.6
billion.
(source: Lockheed Martin)