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.
| || |
SPOOKY AURORAS? NOAA forcasters estimate a 25% chance of polar geomagnetic storms on Oct. 31st when a CME is expected to hit Earth's magnetic field. It was propelled in our direction by an M4-class flare from sunspot AR1882 on Oct. 28th. High-latitude sky watchers should be alert for auroras on Halloween. Aurora alerts: text, voice.
X-FLARE! Earth orbiting satellites have just detected another strong solar flare, this one from departing sunspot AR1875. The blast, which peaked on Oct. 29th at approximately 2148 UT (02:48 PDT), measured X2 on the Richter Scale of Solar Flares. NASA Solar Dynamics Observatory recorded the extreme ultraviolet flash:
Radiation storms and polar radio blackouts are possible in the hours ahead. Stay tuned for updates. Solar flare alerts: text, voice.
SPACE WEATHER BALLOON UPDATE: Members of the Earth to Sky Calculus team have recovered the space weather balloon they launched on Oct. 27th. The payload, which landed in a remote area of California's Inyo Mountains, carried two high-energy radiation sensors into the stratosphere. These pictures show the erupting balloon and one of the sensors at the apex of the flight, 27 km (90,500 feet) above Earth's surface:
The reading on the LCD screen shows a dose rate of 3.7 uSv/hour, more than 20 times higher than radiation levels at the launch site. Another independent sensor was contained inside a thermally insulated capsule. Working together, the two sensors measured a complete profile of ionizing radiation from 2.8 km to 27 km above Earth's surface.
This experiment was prompted by a recent NASA report concerning the effects of space weather on aviation. Like astronauts, ordinary air travelers can be exposed to significant doses of radiation when the sun is active. The Oct. 27th flight showed that it is possible to count x-rays, gamma-rays, alpha particles and beta particles using relatively inexpensive equipment. Such data can be used to check and improve research models of radiation percolating through Earth's atmosphere.
Another balloon flight could be in the offing. Solar activity is high, and a new fusillade of X-flares could trigger a radiation storm around Earth. If so, the student scientists plan to send their sensors back to the stratosphere for another look. Solar flare alerts: text, voice.
Realtime Space Weather Photo Gallery
SUNSPOTS MOST LIKELY TO FLARE: The sun is dotted with spots, and three of them pose a threat for strong eruptions. Today's sunspots most-likely-to-flare are circled in this Oct. 29th image of the sun from NASA's Solar Dynamics Observatory:
AR1875, AR1882 and AR1885 have 'beta-gamma-delta' magnetic fields that harbor energy for X-class solar flares. One of these spots in particular, AR1882, is almost directly facing Earth, so any eruptions it unleashes would almost surely be geoeffective. NOAA forecasters estimate a 70% chance of M-class flares and a 35% chance of X-flares on Oct. 29th. Solar flare alerts: text, voice.
Realtime Space Weather Photo Gallery
Realtime Comet ISON 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 Oct. 29, 2013, the network reported 18 fireballs.
(13 sporadics, 5 Orionids)
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 29, 2013 there were 1435 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 |