From sasha@khors.Stanford.EDU Thu Dec 19 10:55:20 1996 Return-Path: Received: from khors.Stanford.EDU by quake.Stanford.EDU with SMTP (5.65/25-QUAKE-eef) id AA02053; Thu, 19 Dec 1996 10:55:14 -0800 Received: (from sasha@localhost) by khors.Stanford.EDU (8.7.1/8.6.6) id KAA12619; Thu, 19 Dec 1996 10:55:13 -0800 (PST) From: "Alexander Kosovichev" Message-Id: <9612191055.ZM12617@khors.Stanford.EDU> Date: Thu, 19 Dec 1996 10:55:13 -0800 X-Mailer: Z-Mail (3.2.0 26oct94 MediaMail) To: local@quake.Stanford.EDU, jkuhn@solar, erhodes@solar Subject: Hills, valleys found on surface of sun Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Status: R Hills, valleys found on surface of sun Bumps detected by instrument on spacecraft BY GLENNDA CHUI Mercury News Staff Writer SAN FRANCISCO -- The latest news from the sun: It's covered with bumps. For the past few months, an instrument built in Palo Alto has been snapping an image of the edge of the sun every 12 minutes and beaming the information back to Stanford University for analysis. What it found, researchers reported Tuesday, is that bumps -- each about a third of a mile high and five times as wide as the Earth -- dot the sun's surface. ``For the first time we think we see a corrugation -- hills and valleys -- on the surface of the sun,'' Jeffrey R. Kuhn, a solar physicist from Michigan State University, announced at a news conference during the American Geophysical Union's winter conference. ``This is something we can't see from the ground.'' The surprising discovery was made by a team of scientists from Michigan State and Stanford. The instrument, built by Lockheed Martin and Stanford, is flying on a spacecraft known as Solar and Heliospheric Observatory (SOHO), which is giving scientists an unprecedented view of our star from a perch a million miles out from Earth. Far above the blurring effects of the atmosphere, the instrument, known as the Michelson Doppler Imager (MDI), can detect movements of the gases at the edge of the sun of as little as 10 feet. That's the equivalent of measuring a spot the size of a quarter sticking out from the edge of the Earth's moon, said Kuhn. The bumps are subtle and cover the surface fairly regularly, he said. About 60 of them can be seen around the edge of the sun at any given time. They persist in the same place for at least a month, moving across the star's gaseous, burning surface as it rotates. Kuhn and other solar experts, many of whom heard of the discovery only Tuesday, said they had no idea what caused the phenomenon. But they said it could be related to the boiling and bubbling of gases in the outer third of the sun, or to the interaction of this roiling with the sun's enormously strong magnetic field. It's the kind of thing that, having seen, we'll want to follow and understand,'' said Ed Rhodes of the University of Southern California, another member of the instrument team. ``If this turns out to be substantiated, I think it's very exciting. I'm personally just very surprised by the result.'' SOHO is a joint mission of the National Aeronautics and Space Administration and the European Space Agency. Three of its dozen instruments were built in the United States, including the MDI, which was constructed at a cost of $75 million. Launched in December 1995, it is scheduled to remain at work for at least two years. But researchers said they'd like to keep it operating longer because it is returning such a wealth of data -- including information that could be used to forecast giant bursts of destructive particles that periodically erupt from the sun's surface and speed toward Earth, where they sometimes knock out power and damage electronic equipment. Published Wednesday, December 18, 1996, in the San Jose Mercury News