On October 23rd there will be a partial eclipse of the Sun. Got clouds? No problem. The event will be broadcast live on the web by the Coca-Cola Science Center. | | | AURORAS ON MARS TODAY? Today, Oct. 19th, Comet Siding Spring is buzzing Mars. The encounter is so close, the atmosphere of the comet could brush against the atmosphere of the planet. Will this spark auroras on Mars? A video from NASA weighs the odds of some very strange space weather. X1-CLASS SOLAR FLARE: This comes as no surprise. Behemoth sunspot AR2192 has unleashed an X1-class solar flare. NASA's Solar Dynamics Observatory recorded the blast in this extreme UV image of the sun on Oct. 19th (0500 UT):  A pulse of ultraviolet and X-radiation from the flare caused a brief but strong HF radio blackout on the dayside of Earth, mainly over Asia and Australia. Update (8:30 AM PDT): Remarkably, this explosion did not yield a significant CME. Just-arriving coronagraph images from SOHO show no cloud emerging from the blast site. Big sunspots tend to produce big flares, and clearly AR2192 is no exception. More X-flares are likely as AR2192 turns toward Earth in the days ahead. Also, if you have a solar telescope, point it at the sun. This active region is a real beauty. Solar flare alerts: text, voice Realtime Space Weather Photo Gallery EMERALD DYNAMITE: On Oct. 18th, Earth passed through multiple folds in the heliospheric current sheet--a phenomenon known as "solar sector boundary crossings." This sparked a veritable explosion of bright auroras around the Arctic Circle. Ole Salomonsen of Tromso, Norway, captured the outburst in this photo, which he calls Emerald Dynamite:  "This is one of many spectacular auroral displays I captured tonight," says Salomonsen. "There were red auroras, green auroras, coronas, fast moving purple bands... It was the most amazing display I have witnessed in a long time." More auroras are in the offing. NOAA forecasters expect additional solar sector boundary crossings on Oct. 19th with a 30% chance of polar geomagnetic storms before the weekend is over. Aurora alerts: text, voice Realtime Aurora Photo Gallery ORIONID METEOR SHOWER: Earth is entering a stream of debris from Halley's Comet, source of the annual Orionid meteor shower. When the shower peaks on Oct. 21st, pre-dawn sky watchers could see as many as 25 meteors per hour shooting out of the constellation Orion. On Oct. 17-18, NASA's All-Sky Meteor Network detected 4 Orionid fireballs over the USA, a number that could increase sharply as Earth plunges deeper into the debris stream. [full story] [sky map] [meteor radar] Realtime Comet Photo Gallery Realtime Eclipse 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 Oct. 19, 2014, the network reported 26 fireballs. (19 sporadics, 5 Orionids, 2 epsilon Geminids) 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 October 19, 2014 there were 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 | |