Melting away a mystery of sun’s heat
A U.S.-Japanese spacecraft has found a possible explanation for the mystery of what makes the sun’s corona 100 times hotter than its surface: weed-like tangles of magnetism radiating into space.
“Theories suggested that [these] fields might exist,” said Leon Golub, a senior astrophysicist at the Harvard-Smithsonian Center for Astrophysics. Now, “we can see them clearly.”
Images of these lines of magnetism were captured by an X-ray telescope aboard the Hinode spacecraft, which was launched in September on a mission to study the sun at close range.
Scientists have measured the sun’s surface temperature at about 10,000 degrees. Yet the corona, which reaches from the surface to the inner solar system, is about 1 million degrees.
According to the theories, the magnetic fields emanating from the sun’s surface capture huge amounts of energy. When the fields relax, the stored energy is released, super-heating the corona.
Golub presented his finding Wednesday at a NASA meeting in Washington, D.C.
An X-ray telescope can be a more effective tool than a conventional one because X-rays are more powerful forms of radiation than visible light.
A telescope that can see in the X-ray range is well-suited to observe energetic cosmological events, such as black holes and neutron stars.
“We’ve seen many new and unexpected things,” Golub said. “For that reason alone, the mission is already a success.”
Scientists hope Hinode’s observations will help predict space weather patterns that could protect astronauts and spacecraft from the effects of solar eruptions.
