Space Weather Update: 12/08/2016
By Spaceweather.com, 12/08/2016
GEOMAGNETIC STORM WATCH: Earth is entering a stream of solar wind flowing from a large coronal hole on the sun. At the moment, our planet is still in the outskirts of the stream; geomagnetc activity remains relatively low. G1-classgeomagnetic storms could develop on Dec. 8th and 9th as Earth moves deeper into the stream and wind speeds jump as high as 700 km/s. Arctic sky watchers should remain alert for auroras. Free: aurora alerts
GEMINID METEOR SHOWER: 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.
At the moment, visible Geminid meteor rates are no more than a few per hour. 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. 13-14when observers in both hemispheres could see dozens of Geminids despite the glare of a bright full Moon. The best time to look is during the hours after local midnight. [sky map]
AMAZING SUN HALO: Atmospheric optics expert Les Cowley has seen almost every manifestation of ice in the sky that Nature can produce. He’s not easy to impress. On Dec 6th, however, Michael Greenham of Magog, Quebec, photographed a display that impressed even Cowley:
“That is a great one,” says Cowley.
“The air temperature was -1 C on a calm December morning,” says Greenham. Sunlight hitting ice crystals in the air produced “very vivid sundogs and arcs in the sky.”
“This magnificent ice halo display isbristling with rare arcs,” says Cowley. “From top downwards we have a circumzenithal arc. Touching that is a bright and rare supralateral arc, often mistaken for the rarer 46 degree halo. Then we have a Parry arc, first recorded in 1820 by the famous Arctic explorer William Edward Parry. Touching the familiar 22 degree halo is a ‘gull-wing‘ shaped upper tangent arc. Radiating outward from the sun at far left and right are very rare helic arcs.”
Greenham spotted these halos in his front yard. Cowley knows another place to find them: “To best see halos like this choose a subzero day a few km downwind of a ski slope. Snow blowers make high quality halo forming crystals as well as snow!”
STUDENT SPECIAL: Is there a young scientist in your life? For Christmas, you can give them the gift of exploration. For the holiday season only, we’re reducing the cost of payload space on Earth to Sky Calculus balloons from $500 to only $299.95. Buy an edge of space gift certificate before Dec. 25th and your student can send an experiment, photo, or keepsake item to the stratosphere, completely supported by an Earth to Sky Calculus launch and recovery team.
This is not only a great Christmas gift, but also a good kickstarter for science fair projects. Experiments will be flown and returned along with video footage, GPS tracking, temperature, pressure, altimetry and radiation data.
To take advantage of the discounted rate, payment must be received before Dec. 25th. However, the flight can take place at any time in the next 12 months. A Skype brainstorming session is included with each certificate. Dr. Tony Phillips and other members of the Earth to Sky team will chat with students to help them craft an experiment that will work in the harsh environment of the stratosphere.
More far out Christmas gifts may be found in the Earth to Sky Store. All proceeds support space weather research.
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. 8, 2016, the network reported 13 fireballs.
(12 sporadics, 1 Quadrantid)
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 8, 2016 there were 1746 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: 644.2 km/sec
density: 5.9 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1943 UTX-ray Solar Flares
6-hr max: B2 1850 UT Dec08
24-hr: B2 1850 UT Dec08
explanation | more data
Updated: Today at: 1900 UTDaily Sun: 08 Dec 16Departing sunspot AR2615 poses no threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 18
What is the sunspot number?
Updated 08 Dec 2016
Current Stretch: 0 days
2016 total: 25 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 08 Dec 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 4 unsettled
24-hr max: Kp= 4 unsettled
explanation | more data
Interplanetary Mag. Field
Btotal: 6.1 nT
Bz: 1.6 nT south
more data: ACE, DSCOVR
Updated: Today at 1943 UTCoronal Holes: 08 Dec 16
Earth is entering a stream of solar wind flowing from this large coronal hole. 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: 12-07-2016 18:55:03
Updated at: 2016 Dec 07 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 07 2200 UTCMid-latitudes