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. | | | CHANCE OF STORMS: NOAA forecasters estimate a 35% chance of polar geomagnetic storms on Jan. 17th when a minor CME is expected to hit Earth's magnetic field. High-latitude sky watchers should be alert for moonlit auroras. Aurora alerts: text, voice. AURORA, BOOM! On Jan. 11th, Bjørn Hugo Hansen of Øverbygd, Norway, observed an explosive display of auroras--with sound effects. "The temperature was -27 C, and I was standing on the ice by our cabin. In the distance I could hear cracking sounds from the ice, a strange sound like a mix of whale bubbles hitting the ice and a small earthquake. This happens often. I believe it is stronger tonight, though, because of a big drop in temperature. Faint auroras were dancing quietly overhead when I spoke to myself -- 'Come on Aurora – give me all you got.' And BOOM! The sky exploded behind me." This is what he saw: "Lady Aurora twisted around the sky, she threw her bridal veil all around," continues Hansen. "I was in ecstasy … and as if that was not enough, the ice under me made a large DRUN! I had never heard the sound of the ice crack this close before, almost right under me. It was an enormous sound. A thin crack 5mm wide rushed across the lake. Then it became quiet and Aurora disappeared. AMAZING!" A story like that makes you wish you were in Norway. Browse the gallery for more stories from the ice: Realtime Aurora Photo Gallery LIGHT PILLARS: Winter is unfolding around the northern hemisphere. As temperatures drop, pillars of light are springing up from ground. Janis Satrovskis of Valmiera, Latvia, photographed this specimen on Jan. 14th: Light pillars are a common sight around northern cities in winter. Urban lights bounce off ice crystals in the air, producing tall luminous columns sometimes mistaken for auroras. Usually the ice crystals are natural, such as snow flakes, but in this case the atmospheric optics were artificial. "The amazing phenomenon was created by snow blowing machines," explains Satrovskis. "These are our first days with temperatures below zero and ski resorts are making snow. A slight breeze carried manmade snow over the city, creating a spectacular view." Light pillars are springing up in cold cities around the world. Is yours one of them? Browse the gallery for the latest sightings. Realtime Space Weather Photo Gallery Realtime Venus Photo Gallery Realtime Comet 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. 15, 2014, the network reported 6 fireballs. (6 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. 14, 2014, the network reported 12 fireballs. (12 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 17, 2014 there were 1451 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 | |