CHANCE OF STORMS THIS WEEKEND: NOAA forecasters estimate a 40% chance of minor geomagnetic storms on Nov. 4th when a solar wind stream is expected to buffet Earth's magnetic field. This is not a major stream of solar wind, like the one that sparked bright lights during the last week of October. Nevertheless, Arctic sky watchers should be alert for auroras on Friday and Saturday nights. Free: Aurora Alerts
SUNSET SKY SHOW: Last night, Nov. 2nd, the crescent Moon, Venus and Saturn gathered to form a triangle in the sunset sky. The formation was visible around the world even from brightly-lit urban areas. Jingpeng Liu sends this picture from Lincoln, Nebraska:
"Our star party began at sunset as the Moon joined Venus and Saturn for the formation of a triangle in the south-west sky," says Liu. "I seized a chance from the clouds and took this picture with a Canon 6D set at ISO 800 for 8s."
Sunset photographers, take note of those settings. In the weeks ahead the Moon will circle the sky, ultimately returning to Venus on Dec. 3rd. Instead of Saturn, Mars will form the third vertex of the celestial triangle. Mark your calendar for the next sunset sky show.
Realtime Space Weather Photo Gallery
UNRULY AURORAS DISOBEY FORECASTS: The forecast for Nov. 2nd called for no auroras. "But here in Tromso, Norway, the auroras ignored the forecast," reports Michael Zawadzki. "The sky erupted for the second night in a row." The luminous outburst was so wide, he needed a fisheye lens to capture it all:
"The past two nights have been truly remarkable," marvels Zawadzki.
What went wrong with the forecast? It didn't anticipate the interplanetary magnetic field (IMF). On Nov. 1st and 2nd, Earth passed through regions of negative IMF. Lines of magnetic force wrapped themselves around our planet's magnetosphere and pried open a crack, allowing solar wind to pour in and fuel the unpredicted display.
Lesson learned: At this time of year, when dark wintry skies favor visibility, Arctic sky watchers should remain alert for auroras regardless of the forecast. More snapshots of last night's surprise display may be found in the aurora gallery.
WATCH OUT FOR TAURID FIREBALLS: Every year in late October and early November, Earth passes through a river of space dust associated with Comet Encke. Tiny specks of debris hit Earth's atmosphere, producing a minor shower of meteors known as the Taurids. Although the shower is minor (typically, it only produces a few meteors per hour) it is nevertheless remarkable. The debris stream of comet Encke is spiced with gravely nuggets that tend to disintegrate as bright fireballs. Karoly Jonas caught this one blazing over the bright urban lights of Budapest on Oct. 31st:
There are signs that the shower is intensifying as November begins. NASA's network of all-sky meteor cameras has counted more than a dozen Taurid fireballs over the USA in the past few nights.
When should you look? You might see a fireball flitting across the sky any time Taurus is above the horizon. At this time of year, the Bull rises in the east at sunset. The odds of seeing a bright meteor improve as the constellation climbs higher. By midnight, Taurus is nearly overhead, so that is a particularly good time.
Note: This meteor shower requires patience. In fact, it's more of a slow drizzle than a shower. From any given place on Earth, fireballs might appear no more often than once every few hours. A drizzle of fireballs, however, is worth observing. So keep an eye on the sky in the nights ahead for Taurids.
Realtime Space Weather Photo Gallery
Realtime Airglow Photo Gallery