Spotless Days Current Stretch: 0 days 2016 total: 20 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 Sep 2016
Geomagnetic Storms: Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2016 Sep 05 2200 UTC
Monday, Sep. 5, 2016
What's up in space
Directly under the Arctic Circle! Marianne's Arctic Xpress in Tromsø offers fjord, whale and wildlife tours by day, aurora tours by night. Book Now and get a 10% discount on combo day and night adventures.
GEOMAGNETIC STORM: A G1-class geomagnetic storm is underway on Sept. 5th as Earth moves through a broad stream of solar wind. This is the same solar wind stream that sparked bright auroras around both poles over the weekend. High-latitude sky watchers should remain alert for auroras tonight. Aurora alerts: text or voice
'AURORA SEASON' IS UNDERWAY: Around the Arctic Circle, the end of summer is greeted with mixed feelings. The midnight sun sets, taking its cheerful rays below the horizon. The air might not be truly warm again for months. The onset of cold, however, brings something wonderful to behold. This:
"A new season with Northern Lights has started in northern Norway," reports photographer Kristin Berg, who took this picture on Sept. 2nd from Tromsø. "What a night! "
Northern Lights are returning to the Arctic for two reasons. The first is simple: It's getting dark. The exit of the midnight sun is leaving velvety-dark skies where geomagnetic storms can paint their colors. The second is a little more complicated. During the weeks around equinoxes, the tilt of the interplanetary magnetic field favors geomagnetic storms. Even gentle gusts of solar wind can spark bright outbursts of light.
Aurora season has definitely begun. Monitor the photo gallery for more sightings:
THE SOUTHERN LIGHTS OF JUPITER: It must be aurora season on Jupiter, too. On Aug. 27th, NASA's Juno spacecraft flew over the giant planet's south pole and photographed this amazing display:
Until now, Jupiter's southern lights have never been photographed--neither from Earth nor space. Juno's polar orbit revealed the astonishing vortex of infra-red light.
The image was taken by an instrument onboard Juno named JIRAM (Jovian Infrared Auroral Mapper). "While we knew that the first-ever infrared views of Jupiter's south pole might reveal the planet's southern aurora, we were still amazed to see it for the first time," says Alberto Adriani, JIRAM co-investigator from Istituto di Astrofisica e Planetologia Spaziali, Rome.
Another instrument on Juno named "Waves" detected low-frequency (<100 kHz) radio signals coming from Jupiter's auroral oval. Mission scientists at the University of Iowa, where Waves was built, have shifted the signals into the range of human hearing. The audio begins about 30 seconds into this movie:
If the auroras of Jupiter sound mysterious--that's because they are.
Unlike Earth, which lights up in response to solar activity, Jupiter makes its own auroras. The power source is the giant planet's own rotation. Although Jupiter is ten times wider than Earth, it manages to spin around 2.5 times as fast as our little planet. As any freshman engineering student knows, if you spin a magnet you've got an electric generator. And Jupiter is a very big magnet. Induced electric fields accelerate particles toward Jupiter's poles where the aurora action takes place. Remarkably, many of the particles that rain down on Jupiter's poles appear to be ejecta from volcanoes on Io. How this complicated system actually works is a puzzle.
Stay tuned for more space weather reports from Jupiter as Juno continues its explorations of the giant planet.
Updated: Sept.3, 2016 // Next Flight: Sept. 10, 2016
Sept. 3, 2016: On Sept. 2nd, Spaceweather.com and the students of Earth to Sky Calculus conducted a successful transcontinental launch of two space weather balloons--one from New Hampshire and another from California. The New Hampshire balloon recorded the highest levels of atmospheric radiation since our monitoring program began two years ago. Students are reducing the data now, and we will report the results in the coming week.
While you wait, here is a shot of the Atlantic coast of Maine taken during the Sept. 2nd balloon flight from an altitude of 118,000 feet:
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 almost 13% 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.
THIS RESEARCH IS CROWD-FUNDED: The cosmic ray research presented on Spaceweather.com is done by students, driven by curiosity, and funded entirely by readers. Our latest flight over California on Aug. 21st was sponsored by World Tech Toys of Valencia CA. In exchange for their generous donation of $750, we flew a toy Striker Drone to the edge of space:
HD video and poster-quality images of the drone in space are now being used by World Tech Toys for marketing and outreach--an out-of-this-world bargain.
Our next flights on Sept. 2nd and Sept. 10th need sponsors. Would you like to assist? Contact Dr. Tony Phillips to make arrangements.
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 Sep. 5, 2016, the network reported 23 fireballs. (21 sporadics, 1 September epsilon Perseid, 1 Northern iota Aquariid)
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 September 5, 2016 there were potentially hazardous asteroids.