Space Weather Update: 03/21/2016
By Spaceweather.com, 03/21/2016
BRIGHT LIGHTS IN THE EVENING SKY: When the sun goes down tonight, step outside and look east. You’ll see Jupiter and the Moon rising together only a few degrees apart. It’s a beautiful conjunction, and a great way to end the day. [sky map]
SPRING IS AURORA SEASON: Northern Spring has arrived. To know this is true, one only has to look at the night sky over Alaska. Why? Because Spring is aurora season. Dirk Obudzinski sends this picture, taken March 19th, from Fox, Alaska:
“The auroras were brighter than the surrounding moonlit clouds,” says Obudzinski. “It was a fantastic display despite most geomagnetic predictions signaling quiet conditions for last night. You just never know!”
Indeed, this is the time of year when you just never know. For reasons that are only partially understood, the weeks around equinoxes favor geomagnetic storms. Even a gentle gust of solar wind can spark a magnificent display. Stay tuned to the photo gallery for more Spring Green. Aurora alerts: text or voice
GREEN AIRGLOW OVER THE ATACAMA DESERT: Not all green lights in the sky are auroras. Yuri Beletsky discovered this for himself on March 18, 2016, when he looked up from the Atacama desert of Chile:
The green light is called “airglow.” Airglow is a luminous bubble that surounds our entire planet, fringing the top of the atmosphere with aurora-like color. Although airglow resembles the aurora borealis, its underlying physics is different. Airglow is caused by an assortment of chemical reactions in the upper atmosphere driven mainly by solar ultraviolet radiation; auroras, on the other hand, are ignited by gusts of solar wind.
“The sky was literally shining due to quite intense airglow and we were really lucky to witness it,” says Beletsky. “It was so strong that one could hardly see Magellanic clouds through those colorful emissions. In my photo, the domes of the 6.5-m Magellan telescopes are on in the right.”
Green airglow is best photographed from extremely dark sites on nights when the Moon is new or below the horizon. It often shows up in long exposures of the Milky Way. Browse the gallery for more examples:
PLANT YOUR OWN SPACE GARDEN: Spring has arrived, and that means it’s time to plant flowers. Mutant space flowers, that is. These Zinnia seeds flew to the edge of space aboard an Earth to Sky Calculus helium balloon on Feb. 17, 2016:
En route, the seeds were exposed to comic ray doses more than 100x Earth normal, temperatures as low as -63C, and air pressures only 0.3% of sea level.
Zinnias are interesting because they have recently blossomed on the International Space Station. Maybe it’s time to plant these space flowers in your garden, too. For $49.95 you can have some. Each order comes with one seed packet flown to the edge of space, and a second seed packet that was kept on Earth as a control sample. Plant them side by side to discover the effect of near-space flight on your flowers. All proceeds support the student research of Earth to Sky Calculus.
COMET (and FRAGMENTS) APPROACH EARTH: On March 21st, green comet 252P/LINEAR will fly by Earth only 5.4 million km away– the fifth closest cometary approach on record. One day later, a suspected fragment of the comet will pass even closer (3 million km). The name of the fragment is “P/2016 BA14,” and Gregg Ruppel has photographed it zipping among the stars over Animas, New Mexico, on March 18th. Click to view a 40-minute time lapse video:
“I observed P/2016 BA14 using a 10-inch telescope and a STL11000 deep-sky CCD camera,” says Ruppel.
By all accounts, the comet fragment is “pitifully faint.” The parent comet, however, is relatively bright. Indeed, it is now on the threshold of naked eye visibility for observers in the southern hemisphere. Last night, Gerald Rhemann had little trouble photographing the 252P/LINEAR’s green atmosphere from his backyard observatory in Namibia, Africa:
“I used a 12-inch telescope for this 360-second color exposure,” says Rhemann.
The comet is green because its vaporizing nucleus emits diatomic carbon, C2, a gas which glows green in the near-vacuum of space. The verdant color will become even more intense in the nights ahead as 252P/LINEAR approaches Earth.
There is a chance that the comet’s approach could cause a minor meteor shower. According to the International Meteor Organization, “[modeling by forecaster] Mikhail Maslov indicates that there might be a weak episode of faint, very slow meteors (15.5 km/s) on March 28–30 from a radiant near the star μ Leporis.” Little is known about meteors from this comet, so estimates of the meteor rate are very uncertain. Maslov’s models suggest no more than 5 to 10 per hour.
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 Mar. 20, 2016, the network reported 1 fireballs.
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 March 21, 2016 there were 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
Situation Report — Oct. 30, 2015Stratospheric Radiation (+37o N)
Cosmic ray levels are elevated(+6.1% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month.
Sept. 06: 4.14 uSv/hr (414 uRad/hr)
Sept. 12: 4.09 uSv/hr (409 uRad/hr)
Sept. 23: 4.12 uSv/hr (412 uRad/hr)
Sept. 25: 4.16 uSv/hr (416 uRad/hr)
Sept. 27: 4.13 uSv/hr (413 uRad/hr)
Oct. 11: 4.02 uSv/hr (402 uRad/hr)
Oct. 22: 4.11 uSv/hr (411 uRad/hr)
These measurements are based on regular space weather balloon flights: learn more.
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. For example, here is the data from a flight on Oct. 22, 2015:
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.
speed: 423.4 km/sec
density: 12.7 protons/cm3
explanation | more data
Updated: Today at 1328 UTX-ray Solar Flares
6-hr max: B1 0755 UT Mar21
24-hr: B1 0755 UT Mar21
explanation | more data
Updated: Today at: 1300 UTDaily Sun: 21 Mar 16Not one of these sunspots has the type of unstable magnetic field that poses a threat for strong flares. Solar activity remains low. Credit: SDO/HMI
Sunspot number: 25
What is the sunspot number?
Updated 21 Mar 2016
Current Stretch: 0 days
2016 total: 0 days (0%)
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 21 Mar 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 4 unsettled
explanation | more data
Interplanetary Mag. Field
Btotal: 3.3 nT
Bz: 1.8 nT south
explanation | more data
Updated: Today at 1327 UTCoronal Holes: 21 Mar 16
Solar wind flowing from the indicated coronal hole should reach Earth on March 22-23. Credit: SDO/AIA.Noctilucent Clouds The southern season for noctilucent clouds began on Dec. 13, 2015. It is expected to end in late February or March 2016.
Switch view: Ross Ice Shelf, Antarctic Peninsula, East Antarctica, PolarUpdated at: 02-12-2016 16:55:02
Updated at: 2016 Mar 20 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Mar 20 2200 UTCMid-latitudes