 | Martin Ratcliffe
is President, International Planetarium Society (2001-2002) and Director of Theatres and Media Services at Exploration Place and has been involved in all aspects of program development for the Boeing Cyberdome Theater and the Simulation Center. The CyberDome theater continues development of fully interactive shows in immersive domed theatres. Prior to moving to Wichita, he directed the Buhl Planetarium at the Carnegie Science Center in Pittsburgh, PA from 1991 to 1997. Martin co-developed the world's first interactive Planetarium in Armagh, N. Ireland. Martin is also an accomplished writer and monthly columnist for the national magazine, "Astronomy". He also films total eclipses of the Sun for television, and enjoys astrophotography. He is a past Council member of the British Astronomical Association. He earned his Bachelor's of Science degree from University College London (England) in Astronomy. Martin is adjunct professor of Astronomy at Baker University in Wichita, Kansas. |
Astronomy
2002-06-01 17:41:00
Solar Wind
Answer: Our Sun generates a gale force, supersonic, breeze of particles that travel outward through the solar system at a breathtaking 250 miles per second. Strong storms in this "space weather" from the sun can affect satellites, communications and electrical systems on Earth. Understanding how and why this happens is as important as understanding our earthly weather.The scale of this outflow is staggering, measured at one million tons per second. But don't panic. There is enough material in the Sun to sustain this rate for billions of years. This continuous out-flowing wind comes from the extremely hot outer atmosphere of the Sun that is only visible during a total solar eclipse - called the corona. The wind is packed with charged particles called electrons and protons, the basic building blocks of atoms.Thankfully, due to our planet's magnetic field, this electrically-charged wind flows around us and we remain relatively unaffected, unless, however, there is a solar storm. Solar storms can erupt at anytime, typically from regions of sunspots on the Sun. These blasts from the Sun can affect the Earth directly, pumping energy into our near environment, triggering the northern lights (aurora), inducing electrical bursts in power lines and tripping circuit breakers.Comet tails act as windsocks for the solar wind. Comet tails are formed by the solar wind catching gas flowing from the nucleus of the comet, pushing it farther downstream. Many people experienced this effect first hand in 1997 when they viewed Comet Hale-Bopp. A comet's tail always points directly away from the Sun. Changes in the wind can significantly affect the appearance of a comet tail.You can follow space weather at http://www.spaceweather.com/. Most dramatic are hourly time-lapse pictures of the Sun showing regular outbursts in the solar wind, sometimes targeted at Earth. Following an outburst, the northern lights may be visible about two days later, the normal travel time from the Sun to the Earth for these particles. Normally the northern lights are restricted to the northern latitudes, but occasionally, as in November last year, they are visible from Wichita. Every Sunday Exploration Place has free public viewing of the Sun through special telescopes that show dramatic arches of gas leaping off the Sun. This summer, on July 28 at 2 p.m., a visiting solar astronomer will speak at Exploration Place about Solar Storms. See http://www.exploration.org/ for further details.
