When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms. | | | CHINESE MOON ROVER IN TROUBLE: China's moon rover, the Jade Rabbit, which made an historic landing in Sinus Iridum (the Bay of Rainbows) on Dec. 14th, is in trouble. Night is falling over the rover's landing site, and the rover should be going into hibernation to preserve power. China's space agency is reporting, however, that a "mechanical anomaly" may be interfering with the hibernation process. If so, the Jade Rabbit might not survive the extreme cold (-180 C) it is about to experience during two weeks of lunar night. Even if the rover fails, the mission is a success for China, which has joined the exclusive club of nations that have landed on the Moon. OLD SUNSPOT RETURNS, SOLAR ACTIVITY INCREASES: Crackling with solar flares, a large sunspot is emerging over the sun's southeastern limb. It appears to be AR1944, returning after a two-week trip around the farside of the sun. Earlier today, astronomer Karzaman Ahmad photographed the active region from the Langkawi National Observatory in Malasia: According to tradition, sunspots that circle around the farside of the sun are re-numbered when they return. The new designation of AR1944 is AR1967. "Sunspot AR1967 is as big as Earth!" notes Ahmad. Earlier this month, AR1944/AR1967 produced an X1-class solar flare and one of the strongest radiation storms of the current solar cycle. Is round 2 about to begin? Solar activity is definitely increasing as AR1967 comes around the bend. Earth orbiting satellites have detected at least five M-class solar flares since yesterday, including this one recorded on Jan. 28th (07:30 UT) by NASA's Solar Dynamics Observatory: More flares are in the offing. NOAA forecasters estimate a 5% chance of X-flares and a 50% chance of M-flares during the next 24 hours. Solar flare alerts: text, voice Realtime Space Weather Photo Gallery RECTANGULAR SUN: No, it's not an alien planet. It's just Rio. On Jan. 23rd, Helio C. Vital looked out over the ocean from Rio de Janeiro, Brazil, and saw something out of this world--a rectangular sun: As alien as it appeared, this was a phenomenon of Earth. "An inversion air layer next to the sea surface caused the top of the setting sun to acquire unusual shapes. In a matter of tens of seconds, it went from a saucer to a cup, then to a rectangle," says Vital. Atmospheric optics expert Les Cowley explains further: "A mirage morphed the sun into a rectangular block brighter at its top edge. It is even more complex than it seems. Sun rays are deflected (refracted) through the different temperature layers of a temperature inversion, cold air trapped beneath warmer air, to form not one sun image but three or even more. The topmost bright strip is the sun grazing the top of the inversion layer. Beneath it are two or more sun images, half of them rising and the others descending. They overlap to form the rectangle. Other shots show the separate sun images." "Look for these mock-mirages and their green flashes when the horizon shows a dark band of a temperature inversion," he advises. "But take care and never ever use binoculars or a telescope. Magnified sunlight can cause serious eye damage." Realtime Supernova Photo Gallery Realtime Aurora Photo Gallery Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com. On Jan. 28, 2014, the network reported 7 fireballs. (7 sporadics)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies] On Jan. 27, 2014, the network reported 0 fireballs. On Jan. 26, 2014, the network reported 11 fireballs. (11 sporadics)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies] Potentially Hazardous Asteroids ( PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time. On January 28, 2014 there were 1453 potentially hazardous asteroids. Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach. | The official U.S. government space weather bureau | | The first place to look for information about sundogs, pillars, rainbows and related phenomena. | | Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. | | 3D views of the sun from NASA's Solar and Terrestrial Relations Observatory | | Realtime and archival images of the Sun from SOHO. | | from the NOAA Space Environment Center | | the underlying science of space weather | |