Space Weather Update: 12/15/2016
By Spaceweather.com, 12/15/2016
SURFING THE NORTHERN LIGHTS: Australian surfing great Mick Fanning was recently caught riding the waves at Unstad beach in Lofoten, Norway. High overhead, a geomagnetic storm with towering green auroras was underway. Must-see images have just been published by several news outlets: #1, #2, #3.
MORE AURORAS POSSIBLE THIS WEEKEND: Surfers, mark your calendars. A solar wind stream is heading for earth and it could spark a new round of Arctic lights on Dec. 16th. The gaseous stream is flowing from a hole in the sun’s atmosphere, shown here in a Dec. 14th image from NASA’s Solar Dynamics Observatory:
This is called a “coronal hole”–a region in the sun’s atmosphere where the magnetic field opens up and allows solar wind to escape. Some coronal holes are large, covering a majority of the solar disk. This one, however, is small, and the emerging stream is relatively narrow. Earth will probably remain inside the windy zone, dipping in and out, for little more than a day. Stay tuned for updates.
GEMINID METEORS MINGLE WITH MOONLIGHT: Some forecasters predicted the glaring full Moon of Dec. 13th would doom the Geminid meteor shower, reducing it to near invisibility. Bill Metallinos of Corfu, Greece, begs to disagree. “On Dec. 14th we saw some beautiful Geminids,” he says. Indeed, here is the nightscape he recorded above Cape Drastis:
“These two Geminid were easy to see from the clay islets of Peroulades, Corfu,” says Metallinos. “The landscape shines under the light of the Supermoon while the colors of water change because of the clay. The sediments are from lower Paleocene age 1-2 million years ago.”
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. Because of the Geminids’ rocky origin, big meteoroids and bright fireballs like the ones Metallinos photographed are not uncommon.
Today, Dec. 14th, Earth is passing through the heart of 3200 Phaethon’s debris stream and we will begin to exit the debris zone this weekend. The shower should remain active, albeit waning, for the next few nights. If you’re out after dark, be alert for occasional fireballs in the moonlight. [sky map]
THIS CHRISTMAS ORNAMENT HAS BEEN TO SPACE: Would you like to hang something far out from your Christmas Tree? We offer for your consideration the Apollo 8 Christmas ornament. The students of Earth to Sky Calculus recently flew a dozen more of these to the edge of space, and you can have one for $59.95:
The ceramic disk shows an iconic photo from the Apollo program: Earth rising above the Moon as seen by Apollo 8 astronauts on Christmas Eve 1968. Each ornament comes with a Christmas card showing your ornament in the stratosphere and telling the story of its flight.
The cosmic ray research of Spaceweather.com and Earth to Sky Calculus is completely crowd-funded. Everyone who sponsors a balloon flight or buys an item from the Earth to Sky store contributes to this important body of knowledge. Thanks!
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. 15, 2016, the network reported 63 fireballs.
(34 sporadics, 25 Geminids, 3 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.
On December 15, 2016 there were 1748 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:Asteroid
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
Readers, thank you for your patience while we continue to develop this new section of Spaceweather.com. We’ve been working to streamline our data reduction, allowing us to post results from balloon flights much more rapidly, and we have developed a new data product, shown here:
This plot displays radiation measurements not only in the stratosphere, but also at aviation altitudes. Dose rates are expessed as multiples of sea level. For instance, we see that boarding a plane that flies at 25,000 feet exposes passengers to dose rates ~10x higher than sea level. At 40,000 feet, the multiplier is closer to 50x. These measurements are made by our usual cosmic ray payload as it passes through aviation altitudes en route to the stratosphere over California.
What is this all about? 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. Furthermore, there are studies ( #1, #2, #3, #4) linking cosmic rays with cardiac arrhythmias and sudden cardiac death in the general population. Our latest measurements show that cosmic rays are intensifying, with an increase of more than 12% since 2015:
Why are cosmic rays intensifying? The main reason is the sun. Solar storm clouds such as coronal mass ejections (CMEs) sweep aside cosmic rays when they pass by Earth. During Solar Maximum, CMEs are abundant and cosmic rays are held at bay. Now, however, the solar cycle is swinging toward Solar Minimum, allowing cosmic rays to return. Another reason could be the weakening of Earth’s magnetic field, which helps protect us from deep-space radiation.
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 data points in the graph above correspond to the peak of the Reneger-Pfotzer maximum, which lies about 67,000 feet above central California. When cosmic rays crash into Earth’s atmosphere, they produce a spray of secondary particles that is most intense at the entrance to the stratosphere. Physicists Eric Reneger and Georg Pfotzer discovered the maximum using balloons in the 1930s and it is what we are measuring today.
speed: 404.5 km/sec
density: 2.6 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1638 UTX-ray Solar Flares
6-hr max: A7 1244 UT Dec15
24-hr: B2 0330 UT Dec15
explanation | more data
Updated: Today at: 1600 UTDaily Sun: 15 Dec 16Small sunspots 2617 and 2618 pose no threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 25
What is the sunspot number?
Updated 15 Dec 2016
Current Stretch: 0 days
2016 total: 26 days (7%)
2015 total: 0 days (0%)
2014 total: 1 day (<1%)
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%)
Updated 15 Dec 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 1 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 2.8 nT
Bz: -2.8 nT south
more data: ACE, DSCOVR
Updated: Today at 1638 UTCoronal Holes: 15 Dec 16
Solar wind flowing from this large coronal hole should reach Earth on Dec. 19-20. Credit: NASA/SDO.Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17th. Come back to this spot every day to see the “daily daisy” from NASA’s AIM spacecraft, which is monitoring the dance of electric-blue around the Antarctic Circle.
Switch view: Ross Ice Shelf, Antarctic Peninsula, East Antarctica, PolarUpdated at: 12-15-2016 15:55:02
Updated at: 2016 Dec 14 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Dec 14 2200 UTCMid-latitudes