Would you like a call when things are happening in the night sky? Sign up for backyard astronomy alerts from spaceweather.com: voice or text.
| || |
COMET LANDING: No spacecraft has ever landed on a comet--until today. On Wednesday, Nov. 12th, the European Space Agency dropped a lander onto the strangely-shaped core of Comet 67P. Get the full story directly from the ESA.
RADS ON A PLANE: On Nov. 11th, Tony Phillips of spaceweather.com flew from California across the USA to attend a science communications meeting in Washington DC. As an experiment, he decided to take a radiation sensor onboard the plane. The results were eye-opening. During the apex of his flight to DC, cruising 39,000 feet above the desert between Reno and Phoenix, he recorded a dose rate almost 30 times higher than on the ground below:
There was no solar storm in progress. The extra radiation was just a regular drizzle of cosmic rays reaching down to aviation altitudes. This radiation is ever-present and comes from supernovas, black holes, and other sources across the Milky Way.
In a single hour flying between Reno and Phoenix, the passengers on Phillips's flight were exposed to a whole day's worth of ground-level radiation--or about what a person would absorb from an X-ray at the dentist's office. That's not a big deal for an occasional flyer, but as NASA points out, frequent fliers of 100,000 miles or more can accumulate doses equal to 20 chest X-rays or about 100 dental X-rays. Lead aprons, anyone?
The radiation sensor is the same one that Earth to Sky Calculus routinely flies to the stratosphere to measure cosmic rays. It detects X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners. Indeed, when the sensor passed through TSA security at the airport, it began to buzz loudly, signaling a heavy dose of X-rays in the carry-on baggage scanner. TSA agents gathered around the instrument to investigate and they were quite interested when Phillips explained its function. Several wanted to know if they themselves were exposed to radiation in the vicinity of the scanner; a quick scan of the area revealed no leaks.
After boarding the plane, Phillips monitored radiation levels closely. Dose rates tripled within 10 minutes of take-off and remained high for the duration of the flight. This simple experiment shows that space weather can touch us even when the sun is quiet. Imagine what an actual solar storm could do....
Realtime Space Weather Photo Gallery
NORTHERN LIGHTS: Earth is passing through a stream of high-speed solar wind, and this is sparking bright lights around the Arctic Circle. "Last night I was driving home when all of a sudden the sky exploded," reports Frank Olsen, who sends this picture from a frozen lake near Sortland, Norway:
"The sky was bright and clear," says Olsen. "And with the moon lighting up the landscape it was quite perfect."
The display Olsen photographed occurred during a brief but effective G1-class geomagnetic storm. NOAA forecasters estimate a 20% chance of continued storming on Nov. 12th as the solar wind continues to blow. Aurora alerts: text, voice
Realtime Aurora Photo Gallery
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 Nov. 12, 2014, the network reported 21 fireballs.
(16 sporadics, 3 Northern Taurids, 2 omicron Eridanids)
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 November 12, 2014 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters: 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.
|Asteroid || |
|2014 UD192 || |
|2004 JN13 || |
|1998 SS49 || |
|2005 UH3 || |
|2007 EJ || |
|1991 VE || |
| ||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 |