URSID METEOR SHOWER: Earth is passing through a stream of debris from Comet 8P/Tuttle, source of the annual Ursid meteor shower. Forecasters expect the shower to peak on Dec. 22nd with as many as 10 meteors per hour streaming from a radiant near Polaris, the North Star. Occasionally, Earth hits a denser-than-usual patch of debris and rates increase 5- to 10-fold. However, no one can predict when these outbursts occur. Listen for Ursid echoes on Space Weather Radio. Meteor alerts: text, voice
CHRISTMAS CONJUNCTION: According to some scholars, the Star of Bethlehem might have been a close encounter between Venus and Jupiter. The two brightest planets in the night sky, merged, would have made a spectacle of Biblical proportions. This Christmas, NASA's STEREO-B probe is observing a conjunction of three planets--Venus, Earth and Jupiter:
Unlike conjunctions of the distant past, this one includes our home planet. STEREO-B is located on the far side of the sun where it can look back and see Earth along with other worlds in the Solar System. Only NASA's twin STEREO probes, equipped with their high dynamic-range Heliospheric Imagers, can witness this kind of conjunction.
From STEREO-B's point of view, Earth and Jupiter are less than 0.5 degrees apart, while all three planets fit in a circle 3 degrees in diameter. This meeting is not nearly as tight as the putative Star of Bethlehem conjunction ~2000 years ago. At that time Venus and Jupiter could have been as little as 6 arcseconds (0.00166 degrees) apart. Nevertheless, the ongoing conjunction is still a beauty. Stay tuned for updates as the three planets converge.
Realtime Space Weather Photo Gallery
ANALEMMA 2013: If you took a picture of the sun at the same time each day, would it remain in the same position? The answer is no, and the figure-8 shape traced out by the sun over the course of a year is called an analemma.
Japanese photographer "Shiraishi" stitched together more than 50 pictures spanning 12 months to reveal the analemma of 2013 over the city of Kumagaya-shi in Saitama, Japan:
"My analemma project started on December solstice in 2012 and finished on December solstice in 2013," says Shiraishi. "This photo contains the sun images from Jan. 18 to Dec. 22, that is, all the sun images are only in 2013."
The upper and lower tips of the "8" represent the solstices--the longest and shortest days of the year. Today the Japanese sun is at the bottom. Winter has arrived!
Other planets have analemmas, too. Not all are figure-8s, however. The shape depends on the tilt of the planet's spin axis and the eccentricity of its orbit around the sun. Martian analemmas resemble a teardrop, while Jupiter's analemma looks like a jelly-bean:
courtesy: analemma.com
Click here and scroll down to learn more about alien analemmas.
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Solar wind
speed: 322.5 km/sec
density: 2.7 protons/cm3
explanation | more data
Updated: Today at 1956 UT
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X-ray Solar Flares
6-hr max: M3 1512 UT Dec22
24-hr: M3 1512 UT Dec22
explanation | more data
Updated: Today at: 2000 UT
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Daily Sun: 22 Dec 13
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Sunspot AR1928 poses a continued threat for M-class solar flares. Credit: SDO/HMI
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Sunspot number: 131
What is the sunspot number?
Updated 22 Dec 2013
Spotless Days
Current Stretch: 0 days
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days
Update 22 Dec 2013
The Radio Sun
10.7 cm flux: 144 sfu
explanation | more data
Updated 22 Dec 2013
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Current Auroral Oval:
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Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
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Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 1 quiet
explanation | more data
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Interplanetary Mag. Field
Btotal: 3.0 nT
Bz: 1.8 nT north
explanation | more data
Updated: Today at 1956 UT
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Coronal Holes: 20 Dec 13
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Solar wind flowing from the indicated coronal hole could reach Earth on or about Dec. 25th. Credit: SDO/AIA.
