Space Weather Update: 07/05/2016
By Spaceweather.com, 07/05/2016
THE MOST POWERFUL AURORAS IN THE SOLAR SYSTEM: Armored like a tank to protect it from intense radiation, NASA’s Juno spacecraft entered orbit around Jupiter on July 4th. The behemoth spacecraft is on a mission to discover what lies beneath the giant planet’s towering clouds. Bonus: In the months ahead, Juno will fly over Jupiter’s poles for a point-blank view of the most powerful auroras in the solar system. Unlike Earth, which lights up in response to solar activity, Jupiter makes its own auroras in part from the gaseous exhaust of Io’s volcanoes. Get the full story from Dr. Tony Phillips.Aurora alerts: text or voice
MAGNETIC CANYON ON THE SUN: A canyon-shaped hole has opened up in the sun’s atmosphere, and it is spewing solar wind into space. NASA’s Solar Dynamics Observatory is monitoring the structure, which stretches more than 700,000 km from end to end:
This is called a “coronal hole.” Coronal holes are places in the sun’s atmosphere where magnetic fields peel back and allow hot gas to escape. A gaseous stream of solar wind flowing from this opening will reach Earth on July 8th or 9th, possibly sparking polar geomagnetic storms when it arrives. High-latitude sky watchers should be alert for auroras, especially in the southern hemisphere where dark winter skies favor visibility. Aurora alerts: text or voice
AURORAS AND NOCTILUCENT CLOUDS: Who needs sunspots? Despite a lull in solar activity, July began with a beautiful display of color over Calgary, Alberta. Harlan Thomas photographed the sudden apparition of green auroras and silver noctilucent clouds:
“On the evening of June 30th, I faithfully checked the Spaceweather.com AIM daisy and saw that noctilucent clouds were forming over North America,” says Thomas. “So I drove my Jeep to a dark location outside Calgary–and promptly fell asleep.”
“About 30 minutes after midnight on July 1st something woke me up,” he adds. “The noctilucent clouds had appeared, and they were not alone. I was surprised to see some green auroras as well.”
Indeed, the auroras were a surprise. There were no sunspots, no solar flares, and no CMEs on June 30th, yet skies turned green anyway. Here’s what happened: Earth passed through a region of space filled with negative-polarity magnetic fields (known to researchers as “negative B sub z“). Such fields can open a crack in Earth’s magnetosphere. Solar wind pours in and sparks auroras–no sunspots required.
At the same time, an even brighter display of auroras appeared over Antarctica. Browse the gallery for more sightings:
ASTROARTS AT THE EDGE OF SPACE: Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus launch helium balloons to the stratosphere. Their purpose is to monitor cosmic rays, which are intensifying as the solar cycle crashes. All that helium costs money, and our research flights depend on sponsors such as AstroArts–shown here at the edge of space on June 29th:
AstroArts’ generous donation of $500 not only propelled their 25th anniversary display to the edge of space, but also added another crucial data point to the growing record of atmospheric radiation. Thank you, AstroArts!
Readers, if you would like to send an item of your own to the top of Earth’s atmosphere, you can book a flight with as little as two week’s notice. Contact Dr. Tony Phillips to become a sponsor!
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 Jul. 5, 2016, the network reported 36 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 July 5, 2016 there were 1708 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: 336.9 km/sec
density: 3.1 protons/cm3
explanation | more data
Updated: Today at 2002 UTX-ray Solar Flares
6-hr max: B1 2000 UT Jul05
24-hr: B1 2000 UT Jul05
explanation | more data
Updated: Today at: 2000 UTDaily Sun: 05 Jul 16The sun is blank–no sunspots. This means solar activity is very low. Credit: SDO/HMI
Sunspot number: 0
What is the sunspot number?
Updated 05 Jul 2016
Current Stretch: 12 days
2016 total: 16 days (8% to date)
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 04 Jul 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 3.9 nT
Bz: 0.5 nT south
explanation | more data
Updated: Today at 2002 UTCoronal Holes: 05 Jul 16
Solar wind flowing from the indicated coronal hole should reach Earth on July 8-9. Credit: SDO/AIA.Noctilucent Clouds Images from NASA’s AIM spacecraft are once again appearing on Spaceweather.com. Check back daily for space-based sightings of noctilucent clouds.
Switch view: Europe, USA, Asia, PolarUpdated at: 07-05-2016 16:55:02
Updated at: 2016 Jul 04 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Jul 04 2200 UTCMid-latitudes