By Spaceweather.com, 02/05/2017
THE SUN IS FLATLINING: The X-ray output of the sun is flatlining as sunspot counts plummet. This situation is likely to continue for the next three days. NOAA forecasters say there is no more than a 1% chance of strong X-ray solar flares on Feb. 5th, 6th, and 7th.
WEEKEND AURORA WATCH: Auroras are flickering around the Arctic Circle this weekend as Earth passes through a stream of fast-moving solar wind. Markus Varik photographed the display last night in Trosmø, Norway:
“The horses were paying no attention to the auroras,” says Varik, “but they held very still for this picture.”
NOAA forecasters estimate a 25% chance of polar geomagnetic storms on Feb. 5th as Earth slowly exits this stream of solar wind. Although the odds of a storm are relatively low, Arctic sky watchers should remain alert for auroras on Sunday night as the solar wind continues to blow faster than 500 km/s. Free: Aurora alerts.
CORONAL HOLE STARES AT EARTH: A hole has opened in the sun’s atmosphere, and it is spewing a stream of solar wind into space. NASA’s Solar Dynamics Observatory photographed the opening on Feb. 5th pointing almost directly at Earth:
This is a “coronal hole” (CH)–a region in the sun’s atmosphere where the magnetic field has opened up, allowing solar wind to escape. Solar wind flowing from this hole is heading for our planet and could arrive as early as Feb. 7th. Polar sky watchers shoud be alert for auroras when the stream arrives.
FAR-OUT VALENTINE’S GIFT: Did you know that cosmic radiation in Earth’s atmosphere is increasing? It’s true. These and other findings of the Earth to Sky Calculus ballooning program are funded not by government grants or corporate donations. Instead, the students rely on crowdfunding. Or rather, bear-funding:
To raise funds for their ongoing research, on Jan. 31st the students flew a payload-full of these ursine astronauts to the edge of space. You can have one for $79.95. A space rose is included, too, pressed for safekeeping. Each bear+rose duo comes with a Valentine’s card showing the bears in flight and telling the story of their trip to the stratosphere.
More out of this world gifts may be found in the Earth to Sky store.
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 Feb. 5, 2017, the network reported 7 fireballs.
(6 sporadics, 1 alpha Antilid)
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 February 5, 2017 there were 1773 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: 643.7 km/sec
density: 6.0 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1812 UTX-ray Solar Flares
6-hr max: B1 1716 UT Feb05
24-hr: B1 1716 UT Feb05
explanation | more data
Updated: Today at: 1800 UTDaily Sun: 05 Feb 17These sunspots are quiet and pose no threat for strong flares. Credit: SDO/HMI
Sunspot number: 22
What is the sunspot number?
Updated 05 Feb 2017
Current Stretch: 0 days
2017 total: 10 days (29%)
2016 total: 32 days (9%)
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 05 Feb 2017
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 4 unsettled
explanation | more data
Interplanetary Mag. Field
Btotal: 3.4 nT
Bz: -2.9 nT south
more data: ACE, DSCOVR
Updated: Today at 1811 UTCoronal Holes: 05 Feb 17
Earth is inside a stream of solar wind flowing from the indicated coronal hole. Credit: NASA/SDO.Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17, 2016. 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: 02-05-2017 17:55:03
Updated at: 2017 Feb 04 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2017 Feb 04 2200 UTCMid-latitudes