Marianne's Heaven On Earth Aurora Chaser Tours Chasethelighttours.co.uk invites you to join them in their quest to find and photograph the Aurora Borealis. Experience the winter wonderland in the Tromsø Area.
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QUIET WITH A SLIGHT CHANCE OF FLARES: With no sunspots actively flaring, solar activity is low. One sunspot could break the quiet: AR2470 is large and has a magnetic field that harbors energy for significant explosions. NOAA forecasters estimate a 15% chance of M-class flares on Dec. 15th. Solar flare alerts: text or voice
GEMINID METEOR UPDATE: Last night, Dec. 14-15, NASA's network of all-sky meteor cameras detected 148 Geminid fireballs over the USA. The shower was supposed to peak on Dec. 13-14. These data suggest, however, that the Geminids are still active. Earth remains inside a stream of gravelly debris from "rock comet" 3200 Phaethon, the shower's source. Jeff Dai caught this Geminid disintegrating over Bhaktapur Durbar Square in Nepal on Dec. 15th:
"The Geminids were so bright and active that I could see them through the lights of the city," says Dai. "Bhaktapur Durbar Square is the plaza in front of the royal palace of the old Bhaktapur Kingdom. It is one of three Durbar Squares in the Kathmandu Valley in Nepal, all of which are UNESCO World Heritage Sites."
Worldwide observers have reported meteor rates as high as 100 per hour in dark-sky locations. Counts should decline tonight, Dec. 15-16, as Earth begins to leave the debris stream. For now, though, the Geminids remain active. The best time to look is during the dark hours between local midnight and dawn.
Realtime Meteor Photo Gallery
POLAR STRATOSPHERIC CLOUDS: An outbreak of polar stratospheric clouds (PMCs) is underway around the Arctic Circle. Unlike normal grey-white clouds, which hug Earth's surface at altitudes of only 5 to 10 km, PMCs float through the stratosphere (25 km) and they are fantastically colorful. Sarah Skinner saw this specimen high above Abisko, Sweden:
"Just as I was heading out to de-ice the car on Dec. 14th, I looked up and noticed the most incredible cloud formation," says Skinner. "At the same time, an excited text came through from my boss, aurora tour guide Chad Blakley, who having lived here for many years has seen this only once or twice and explained to an Arctic newbie like me how rare these formations really are."
Also known as "nacreous" or "mother of pearl" clouds, the icy structures form in the lower stratosphere when temperatures drop to around minus 85ºC. Sunlight shining through tiny ice particles ~10µm across produce the characteristic bright iridescent colors by diffraction and interference. Once thought to be mere curiosities, some PMCs are now known to be associated with the destruction of ozone.
"Nacreous clouds far outshine and have much more vivid colours than ordinary iridescent clouds, which are very much poor relations and seen frequently all over the world," writes atmospheric optics expert Les Cowley. "Once seen they are never forgotten."
Realtime Space Weather Photo Gallery
GEOMAGNETIC STORMS: A co-rotating interaction region (CIR) struck Earth's magnetic field on Dec. 14th, followed shortly thereafter by a high-speed stream of solar wind. The double jolt sparked almost 9 hours of G1-class geomagnetic storms and auroras around the Arctic Circle. Brian Whittaker saw the display from the cockpit of an airplane 35,000 feet above Northern Manitoba, Canada:
"In addition to the auroras, the Geminid meteor shower was very active," says Whittaker.
More auroras are in the offing on Dec. 15th. NOAA forecasters estimate a 60% chance of continued storming as the solar wind continues to blow. Aurora alerts: text or voice
Realtime Aurora 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 Dec. 15, 2015, the network reported 244 fireballs.
(143 Geminids, 90 sporadics, 4 December Leonis Minorids, 2 , 2 sigma Hydrids, 1 December Monocerotid, 1 , 1 Comae Berenicid)
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 December 15, 2015 there were 1645 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.
| ||Cosmic Rays in the Atmosphere |
These measurements are based on regular space weather balloon flights: learn more.
|Situation Report -- Oct. 30, 2015 ||Stratospheric Radiation (+37o N) |
|Cosmic ray levels are elevated (+6.1% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month. |
|Sept. 06: 4.14 uSv/hr (414 uRad/hr) |
|Sept. 12: 4.09 uSv/hr (409 uRad/hr) |
|Sept. 23: 4.12 uSv/hr (412 uRad/hr) |
|Sept. 25: 4.16 uSv/hr (416 uRad/hr) |
|Sept. 27: 4.13 uSv/hr (413 uRad/hr) |
|Oct. 11: 4.02 uSv/hr (402 uRad/hr) |
|Oct. 22: 4.11 uSv/hr (411 uRad/hr) |
Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere over California. These balloons are equipped with radiation sensors that detect cosmic rays, a surprisingly "down to Earth" form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Our measurements show that someone flying back and forth across the continental USA, just once, can absorb as much ionizing radiation as 2 to 5 dental X-rays. Here is the data from our latest flight, Oct. 22nd:
Radiation levels peak at the entrance to the stratosphere in a broad region called the "Pfotzer Maximum." This peak is named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. Radiation levels there are more than 80x sea level.
Note that the bottom of the Pfotzer Maximim is near 55,000 ft. This means that some high-flying aircraft are not far from the zone of maximum radiation. Indeed, according to the Oct 22th measurements, a plane flying at 45,000 feet is exposed to 2.79 uSv/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in about 5 hours.
The radiation sensors onboard our helium balloons detect 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.
| ||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 |
| ||a sponsor of SpaceWeather.com |
| ||Web-based high school science course with free enrollment |
| ||the underlying science of space weather |