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SOLAR OUTLOOK: Solar activity is very low today and it should remain low for at least the next three days. Unless something unexpected happens, bright auroras are unlikely this week.
HARVEST MOON: Step outside tonight at sunset and look east. See the Moon? That's the Harvest Moon--named long ago by farmers who relied on its light to harvest autumn crops after dark. Tomorrow night the Harvest Moon will be full and extra-beautiful. Don't miss it!
OK, all full Moons are beautiful, but there's something else special about the full Harvest Moon. Do you know what? Get the answer from Science@NASA.
ASTEROID FLYBY: 4179 Toutatis, a weirdly tumbling 2-by-5 km asteroid, is flying past Earth this week. At a distance of only one million miles (about 4 times farther from Earth than the Moon), this big space rock is glowing as brightly as a 9th magnitude star--an easy target for backyard telescopes.
Above: Toutatis moves among the stars of Capricornus on Sept. 23rd. Click to view the complete movie made by Alberto Quijano Vodniza et al. at the University of Nariño Observatory in Columbia.
Observers in the southern hemisphere are favored. Toutatis is south of the celestial equator, today scooting through the constellation Microscopium. On Sept. 29th, the date of closest approach, it will pass about 1o from the star Alpha Centauri as seen from Australia and New Zealand. [ephemeris] [finder charts]
During previous near-Earth flybys, astronomers pinged the space rock using NASA's Goldstone and Arecibo radars. They pinpointed Toutatis' orbit, showing that it poses no danger to Earth for centuries at least, and mapped Toutatis' bizarre surface. Radar observations again this year aim to measure Toutatis' Yarkovsky acceleration.
AURORA SEASON: Northern autumn has begun, and that means it's aurora season. Strange but true: there are more geomagnetic storms around the autumnal equinox than any other time of the year. Would you like a phone call when the next storm begins? Sign up for Spaceweather PHONE.
The first auroras of autumn 2004, pictured right, appeared on Sept. 22nd over Yellowknife in the Northwest Territories of Canada. "This storm happened as we were here at the mine shaft taking photos. It was great and lit up the sky all around us!" says photographer Andrew Eaton. [gallery]