On Friday evening, March 30, I received a phone call from Kim Cohan telling me that a friend of his from Carmel Valley had called him to ask why the night sky looked red. As it turned out, this was a rare instance of the aurora being visible this far south. Indeed, that night there were reports from across the southern U.S., and even from as far south as Mexico, of red and green glows in the night sky.
While the aurora borealis is often visible from nothern locations, it takes a violent solar event to produce aurora effects visible from the mid latitudes, and this occasion was due to a coronal mass ejection from the largest sunspot in a decade (see illustration). NASA's ACE (Advanced Composition Explorer) spacecraft detected a shock wave in the solar wind, which arrived in Earth's atmosphere about 30 minutes later.
When Kim's phone call alerted me to go outside and look up, I saw a faint, diffuse red glow from the northwest horizon to the zenith. The effect was subtle, but I was sure it was real. Later, I saw a number of photographs taken that night from the southern U.S. and they all showed a fairly uniform red glow. The glow is emission from ionized oxygen and nitrogen in the atmosphere.
The next day, I called FOM member Robin Casady about this event, and he responded with this excellent image of the monster sunspot that caused this unusual event.
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The largest sunspot in ten years; the round black spot indicates the size of the Earth. Image by Robin Casady, using a 130mm Astro-Physics refractor at f/16.6 and an Astrovid 2000 video camera. |
Calendar of Events |
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Fall Lecture: Dr. Alex Filippenko will speak on Einstein's Biggest Blunder? The Case for Cosmic "Antigravity." MPC Room 103, 7 p.m. November 10th.
The Bonestell Memorial Lecture: Dr. Frank Shu, the preeminent theorist on the formation of our Solar System, will discuss the formation process of the sun & planets.
Winter Lecture: Dr. Imke de Pater will show the Universe through the eyes of telescopes using the latest techniques in adaptive optics.
Lecture dates to be announced.
Note: All lectures, star parties, and tours arc free and open to the public. Call the MIRA office at (831) 883-1000 or email us at miraŽmira.org for more information.
Your Contributions to the FRIENDS OF MIRA are essential to the growth of this organization. Please join us as we support the exploration of the universe from the Central Coast. Renew your membership today and bring the excitement of amazing astronomical discovery to young and old alike!
MIRA has several interesting projects that we will be working on in the coming year - please phone the office at 883-1000 or email us at mira@iimira.org and let us know of your talents and interests!
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Last updated 3/8/02 DMC