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GEMINID METEOR SHOWER: Mark your calendar: The annual Geminid meteor shower, caused by rock comet 3200 Phaethon, peaks this year on Dec. 14th. On that date, dark-sky observers around the world could see as many as 120 meteors per hour. As November comes to a close, Earth is entering the outskirts of 3200 Phaethon's debris stream, causing a slow drizzle of meteors weeks ahead of peak night. The first Geminid fireball of the season was detected over the USA on Nov. 26th by NASA's network of all-sky meteor cameras. Meteor alerts: text, voice
GREEN THANKSGIVING: On Nov. 27th, Earth passed through a fold in the heliospheric current sheet--also known as a "solar sector boundary crossing." This turned Arctic skies green and made some photographers very thankful:
"Last night our group of eight guests enjoyed an unbelievable display at the Aurora Sky Station!" says tour guide Chad Blakley of the Abisko National Park in Sweden. "Several of our guests were Americans. As you might imagine they were extremely happy to spend Thanksgiving under a multicoloured sky."
Effects of the solar sector boundary crossing are now subsiding and solar wind conditions have returned to normal. NOAA forecasters estimate a relatively slight 10% chance of polar geomagnetic storms on Nov. 28th. Aurora alerts: text, voice
Aurora Photo Gallery
SUNSPOTS OF INTEREST: The sunspot number is rising as a pair of new active regions emerges over the sun's eastern limb. Click to view a 48 hour movie from NASA's Solar Dynamics Observatory:
Three of the six sunspot groups now facing Earth have 'beta-gamma' magnetic fields that harbor energy for M-class solar flares. Of particular interest is AR2222 (circled). Having tripled in size since it appeared two days ago, it seems more likely to erupt than any of the others. NOAA forecasters estimate a 30% chance of M-flares on Nov. 28th. Aurora alerts: text, voice
Space Weather Photo Gallery
SPACE WEATHER BALLOON EXPLODES: On Nov. 23rd, the students of Earth to Sky Calculus launched a Space Weather Buoy to the stratosphere. Carried aloft by a suborbital helium balloon, the payload contained a pair of X-ray/gamma-ray sensors to measure cosmic radiation levels inside Earth's ozone layer. About 90 minutes after launch, this is what happened:
The balloon exploded: #1, #2, #3, #4.
It's supposed to do that. As a weather balloon ascends, it expands into the rapidly thinning air high above Earth. The diameter multiplies until the growing sphere is as wide as a small house. Eventually, the rubber fabric of the balloon reaches its elastic limit, and it ruptures. If it didn't, we would never get the payload back!
This balloon exploded at an altitude of 102,986 feet. The almost-silent blast was captured by a camera looking up from the payload below. Next, a parachute opened and the payload descended to Earth, landing in a remote corner of Death Valley where an Earth to Sky recovery team retrieved it yesterday.
The students and their mentor Dr. Tony Phillips of spaceweather.com are examining the radiation data now. This is the first time they have flown two radiation sensors. Cross-calibrating the two sensors in a single flight will allow the team to fly them separately on future missions, launching multiple balloons in rapid succession to investigate the dynamics of solar storms. Stay tuned for updates.
Space Weather Photo Gallery
Comet Photo Gallery
Every night, a network
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. 27, 2014, the network reported 31 fireballs.
(28 sporadics, 2 November omega Orionids, 1 Geminid)
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
all the time.
November 28, 2014 there were 1517
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.
official U.S. government space weather bureau
first place to look for information about sundogs,
pillars, rainbows and related phenomena.
call it a "Hubble for the sun." SDO
is the most advanced solar observatory ever.
views of the sun from NASA's Solar and Terrestrial
and archival images of the Sun from SOHO.
the NOAA Space Environment Center
underlying science of space weather