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.

CO-ROTATING INTERACTION REGION: NOAA forecasters estimate a 55% chance of polar geomagnetic storms on Dec. 10th when a co-rotating interaction region (CIR) is expected to hit Earth's magnetic field. CIRs are transition zones between fast- and slow-moving solar wind streams. Solar wind plasma piles up in these regions, producing density gradients and shock waves that do a good job of sparking auroras. Aurora alerts: text or voice

THE GEMINID METEOR SHOWER IS UNDERWAY: Canada's Meteor Orbit Radar (CMOR) is picking up echoes from the constellation Gemini. It's a sign that the annual Geminid meteor shower is underway. The bright pink "hot spot" in this CMOR sky map shows where Geminid meteoroids are hitting the atmosphere:

Geminid meteoroids are gravelly debris from "rock comet" 3200 Phaethon. They hit Earth's atmosphere traveling ~35 km/s (78,000 mph) and typically disintegrate about 80 km (50 miles) above Earth's surface. While many Geminids are faint, bright fireballs are not unusual. Indeed, NASA's all-sky network of meteor cameras recorded 10 Geminid fireballs over the USA just last night.

Hakan Bayindir captured this Geminid over Uludag, Bursa, Turkey, on Dec. 8th:

"This is a 15 second exposure I made using my Canon EOS 600D digital camera set at ISO 1600."

Photographers should take note of those settings because many more Geminids are in the offing. Meteor sightings will increase in the nights ahead as Earth plunges deeper into the debris zone of 3200 Phaethon. 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 during the hours after local midnight. 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.

Realtime Meteor 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

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Realtime Space Weather Photo Gallery

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Realtime Aurora Photo Gallery

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All Sky Fireball Network

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. 10, 2015, the network reported 36 fireballs.
(23 sporadics, 6 Geminids, 6 sigma Hydrids, 1 December Monocerotid)

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]

Near Earth Asteroids

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. 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

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.

Essential web links

NOAA Space Weather Prediction Center

The official U.S. government space weather bureau

Atmospheric Optics

The first place to look for information about sundogs, pillars, rainbows and related phenomena.

Solar Dynamics Observatory

Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever.

STEREO

3D views of the sun from NASA's Solar and Terrestrial Relations Observatory

Solar and Heliospheric Observatory

Realtime and archival images of the Sun from SOHO.

Daily Sunspot Summaries

from the NOAA Space Environment Center

Heliophysics

the underlying science of space weather

Synergy Spray Foam Insulation of Houston TX

Protection from the Sun!

Kotton Grammer, Search Engine Marketing

a sponsor of SpaceWeather.com

Columbia Northern High School

Web-based high school science course with free enrollment

Heliophysics

the underlying science of space weather

more links...