Space Weather Update: 03/08/2017
By Spaceweather.com, 03/08/2017
ARCTIC SPACE WEATHER BALLOONS: Today, Spaceweather.com and the students of Earth to Sky Calculus are flying to Sweden to launch a series of space weather balloons above the Arctic Circle. We’ll be measuring cosmic radiation, photographing Northern Lights from the stratosphere, and sampling polar stratospheric clouds. The first launch could occur as early as March 10th. Stay tuned!
SPOTLESS SUN SPARKS BRIGHT AURORAS: The sun has been completely blank for 48 hours–no sunspots at all. Who needs them? Throughout that interval, geomagnetic disturbances and bright auroras have pulsed around the Arctic Circle. Last night in Abisko, Sweden, tour guide Sarah Skinner barely had time to set up her cameras before the sky erupted:
Arriving at the site, I mobilized the guests and cameras as fast as possible–the auroras were already in full swing,” says Skinner. “The display gained in intensity as the evening progressed with superb greens andvisible pinks.”
Sunspots are a well-known metric of space weather. When sunspot counts are high, magnetic disturbances and polar auroras are common. Turns out the same is true when sunspot counts are low. Last night’s display was caused by solar wind flowing from a hole in the sun’s atmosphere–no sunspots required.
The sunspot cycle is crashing toward a new solar minimum expected in 2019-2020. Last night’s display confirms that space weather does not stop when sunspots vanish. Indeed, in many ways, it just gets more interesting.
THE TRANSFORMATION OF VENUS: On March 25th, Venus will pass almost directly between Earth and the sun–an event astronomers call “inferior solar conjunction.” As Venus approaches the sun, the planet is turning its night side toward Earth, reducing its luminous glow to a thin sliver. Astrophotographer Raffaello Lena ofRome, Italy, has been monitoring the transformation:
“The progression of the crescent as Venus approaches inferior conjunction is clear,” says Lena. “I took these pictures using an 18 cm (7 inch) Mak Cassegrain telescope.”
You don’t need such a large telescope, however, to see the shape of Venus. Even ordinary binoculars will show the crescent. Amateur astronomers are encouraged to monitor Venus in the lead-up to inferior conjunction. In the nights ahead, the crescent of Venus will become increasingly thin and circular. The horns of the crescent might actually touch when the Venus-sun angle is least on March 25th.
Look for Venus shining brightly in the western sky at sunset–you can’t miss it!
NORTHERN LIGHTS SPACE PENDANT: To raise money for their trip to the Arctic Circle, on March 2nd the students of Earth to Sky Calculus flew a payload-full of Northern Lights pendants to the edge of space above California. You can have one for $69.95. Each piece of jewelry comes with a greeting card telling the story of the pendant’s trip to the stratosphere and certifying its peak altitude: 112,200 feet above Earth’s surface.
Bonus: Would you like your pendant to fly above the Arctic Circle as well? Make a note in the COMMENTS box at checkout and we will take your pendant to Sweden for a second trip to the stratosphere.
More far-out gifts may be found in the Earth to Sky Store. All proceeds support STEM education and high-altitude ballooning.
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. 8, 2017, the network reported 11 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 8, 2017 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
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.
Daily Sun: 08 Mar 17
The sun is blank–no sunspots. Credit: SDO/HMI
Sunspot number: 0
What is the sunspot number?
Updated 08 Mar 2017
Current Stretch: 2 days
2017 total: 14 days (20%)
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 08 Mar 2017
Current Auroral Oval:
Coronal Holes: 08 Mar 17
Solar wind flowing from this disorganized coronal hole could brush against Earth’s magnetic field on March 9-11. It is unlikely to have a strong effect on our planet’ space environment, though. 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.
Updated at: 02-24-2017 17:55:02
Updated at: 2017 Mar 07 2200 UTC
Updated at: 2017 Mar 07 2200 UTC