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. | | | GEMINID METEOR SHOWER: Earth is entering a stream of gravelly debris from "rock comet" 3200 Phaethon, source of annual Geminid meteor shower. Forecasters expect peak rates to occur on Dec. 13-14, when dark-sky observers in both hemispheres could see as many as 120 meteors per hour. Observing conditions will be nearly ideal because the shower peaks just a few days after the New Moon. Stay tuned for updates and, meanwhile, listen for Geminid echoes in the audio feed from our live meteor radar. ARCTIC RECYCLING BINS: A co-rotating interaction region (CIR) hit Earth's magnetic field on Dec. 10th, and a high-speed stream of solar wind arrived soon thereafter. The double blow sparked bright auroras around the Arctic Circle. Oliver Wright photographed the display from Abisko, Sweden: "I was setting up to guide a Lights Over Lapland aurora photo tour," says Wright. "I had good expectations because of the co-rotating interaction region I'd seen forecast on Spaceweather.com. As I was waiting for the guests to arrive, I just popped my head out of the door to see a huge aurora developing. We can't always pick our compositions, but I reckon I might have got one of the best shots of the hotel's recycling bins in history!" Arctic sky watchers should be alert for more auroras in the nights ahead. NOAA forecasters estimate a 45% chance of polar magnetic storms on Dec. 11 as the solar wind continues to blow. Aurora alerts: text or voice Realtime Aurora Photo Gallery LOCATING COMET CATALINA: How do you find Comet Catalina? Just go to Venus and turn left. Fritz Helmut Hemmerich photographed the pair from Tenerife, Canary Islands, on Dec. 9th: Comet Catalina is passing by Venus in the morning sky this week, with only a few degrees separating the two. So let Venus be your guide. Wake up before sunrise, locate the Goddess of Love, and scan the surrounding sky using binoculars. Voilà --a comet! Detailed sky maps may be found in this article from Sky and Telescope. Why does Comet Catalina have two tails? Almost all comets do. The sun-warmed nucleus of a comet spews a mixture of dust and gas into space. Quickly, the mixture separates into two distinct tails: The gaseous "ion tail" is pushed straight away from the sun by solar wind. The weightier dust tail resists solar wind pressure and aligns itself more or less with the comet's orbit. In Hemmerich's picture of Comet Catalina, the ion tail points up; the dust tail points down. This is Comet Catalina's first visit to the inner solar system--and its last. The comet's close encounter with the sun in mid-November has placed it on a slingshot trajectory toward interstellar space. It will become easier to see in the weeks ahead as it approaches Earth, possibly brightening to 5th magnitude--barely visible to the naked eye and an easy target for backyard telescopes. Resources: 3D orbit, ephemerides. Realtime Comet Photo Gallery Realtime Meteor Photo Gallery Realtime Space Weather 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. 11, 2015, the network reported 29 fireballs. (16 sporadics, 6 Geminids, 4 sigma Hydrids, 2 December Monocerotids, 1 alpha Canis Majorid) 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 11, 2015 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. | Cosmic Rays in the Atmosphere | 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) | These measurements are based on regular space weather balloon flights: learn more. 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 | |