Listen to radar echoes from satellites and meteors, live on listener-supported Space Weather Radio. | | | MOSTLY QUIET WITH A CHANCE OF FLARES: Solar activity is low. However, two sunspots have 'beta-gamma' magnetic fields that harbor energy for moderately-strong flares. NOAA forecasters estimate a 30% chance of M-flares during the next 24 hours. Solar flare alerts: text, voice FARSIDE PLANETARY CONJUNCTION: Mercury and Saturn are converging for a tight conjunction in the night sky. Just one problem: You have to be on the far side of the sun to see it. NASA's STEREO-B probe is perfectly positioned to observe the convergence: Late in the day on Saturday, May 17th, the distance between the two planets will narrow until they become nearly indistinguishable. If this event were visible from our side of the sun, it would surely be headline news. NASA's STEREO probes see many things that we cannot. From their orbits high above the farside of the sun, they track hidden sunspots, anti-Earth-directed solar flares, and intterplanetary CMEs. STEREO's wide-field Heliospheric Imagers also have a unique view of the planets. See above. This weekend's conjunction of Mercury and Saturn is bracketed by Mars and Earth itself, an arrangement impossible to observe from terra firma. Realtime Space Weather Photo Gallery EXTREMOPHILES BLASTED BY COSMIC RADIATION: On May 10th, the students of Earth to Sky Calculus flew four colonies of halobacteria to the stratosphere, setting a high-altitude ballooning record for this species of microbe. During the two and a half hour flight, they ascended to 111,000 feet. Radiation data from an X-ray/gamma-ray sensor on the payload have just been analyzed and, suffice it to say, the microbes had a blast: The halobacteria were hit by ionizing radiation 28 times stronger than at ground level, similar to what they might experience on the planet Mars. It might seem counterintuitive that the radiation peak did not occur at the apex of the flight. Instead, the extremophiles absorbed their greatest dose about half way up. This peak at ~60,000 feet is the "Pfotzer Maximum," named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. When cosmic rays crash into Earth's atmosphere, they produce a spray of secondary particles. With increasing depth in the atmosphere, primary cosmic rays decrease as the secondary particles increase. This complex situation results in a maximum dose rate in the tropopause, not the overlying stratosphere. . The students have been flying halobacteria through the Pfotzer Maximum to explore the possibility that terrestrial extremophiles could survive in places like Mars. The answers are growing inside an incubator in the students' AP Biology classroom. Stay tuned for updates from the Petri dish. Realtime Space Weather Photo Gallery Realtime Aurora Photo Gallery Realtime Mars 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 May. 17, 2014, the network reported 13 fireballs. (12 sporadics, 1 eta Aquariid)
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 May 17, 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 | |