Space Weather Update: 09/15/2016
By Spaceweather.com, 09/15/2016
ALMOST NO CHANCE OF FLARES: With no sunspots actively flaring, the sun’s X-ray output is flatlining. This situation is likely to continue for the rest of the week. NOAA forecasters say there is no more than a 1% chance of strong flares for the next 3 days. Free: Space Weather Alerts.
SPOOKY ECLIPSE OF THE HARVEST MOON: According to folklore, this Friday’s full Moon is the Harvest Moon. For many observers, the usual luster of the silver orb will be dimmed by a spooky shadow as the Moon experiences a “penumbral lunar eclipse.” Larry Koehn of ShadowandSubstance.com has created an excellent animation of the event.
A penumbral eclipse happens when the Moon passes through the pale outskirts of Earth’s shadow. It is much less dramatic than a “blood moon” total lunar eclipse. In fact, when observers are not alerted beforehand, they often do not realize an eclipse is underway. Nevertheless, the subtle shadow of Earth is visible to the naked eye ifyou know it’s there.
The eclipse will not be visible in the Americas. Observers there can enjoy the Harvest moonlight, undimmed, while watching the eclipse unfold elsewhere in therealtime photo gallery.
EARTH’S MAGNETIC FIELD RINGS LIKE A BELL: In the Lofoten Islands of Norway, Spaceweather.com reader Rob Stammes operates a magnetic observatory. Twnty-four hours a day, he measures the strength and direction of the local magnetic field as well as electrical currents running through the ground. During geomagnetic storms, his chart recordings go haywire. On Sept. 12th, something different happened. They rang like a bell:
“During the morning and especially around noon, sinusoidal pulsations appeared on my instruments,” says Stammes. “The period was close to 115 seconds (8.7 mHz).”
These are natural ultra-low frequency oscillations known to researchers as “pulsations continuous” (Pc). The physics is familiar to anyone who has studied bells or resonant cavities. Earth’s magnetic field carves out a cavity in the surrounding solar wind. Pressure fluctuations in the solar wind can excite wave modes in this cavity much like Stammes observed. References: #1, #2, #3.
The magnetic oscillations of Sept. 12th were Pc4 waves. In other words, their frequency fell in the range 6.7–22 mHz. Pc4 waves, and their even lower frequency cousins Pc5 waves (1.7–6.7 mHz), can energize particles in Earth’s inner magnetosphere because these frequencies match and reinforce the natural motion of particles around the geomagnetic field. It’s a resonance phenomenon–like pushing a child on a swing. Matching the time of each push to the natural period of the swing energizes the system and sends the child swinging high in the air.
Perhaps it is no surprise, then, that bright auroras were observed on both Sept. 11th and 12th. Ole Salomonsen photographed these from the window of an airplane just before sunrise in Norway:
“To get the shot using a handheld camera on a moving plane was not easy,” says Salomonsen. “I draped one of my jackets to over me and the window to prevent cabin-light reflections ruining the shot. The people sitting next to me must have had a good laugh 🙂 Anyway I think it was worth it. Observing auroras from the air is definitely special”–even more so when Earth’s magnetic field is acting strangely.
Rob Stammes has been monitoring magnetic pulsations in Norway for years. “They seem to occur most often around the equinoxes,” he says. That means we should stay tuned for more. The northern autumnal equinox (Sept. 22nd) is now less than a week away. Aurora alerts: text or voice
Cosmic Rays in the Atmosphere
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. 15, 2016, the network reported 19 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 September 15, 2016 there were 1731 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.
speed: 315.3 km/sec
density: 2.3 protons/cm3
explanation | more data
Updated: Today at 2106 UTX-ray Solar Flares
6-hr max: B1 1627 UT Sep15
24-hr: B4 0438 UT Sep15
explanation | more data
Updated: Today at: 2100 UTDaily Sun: 15 Sep 16Not one of these sunspots poses a threat for strong explosions. Solar flare activity remains very low. Credit: SDO/HMI
Sunspot number: 24
What is the sunspot number?
Updated 15 Sep 2016
Current Stretch: 0 days
2016 total: 20 days (8%)
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 15 Sep 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 3 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 5.6 nT
Bz: 5.1 nT north
explanation | more data
Updated: Today at 2105 UTCoronal Holes: 15 Sep 16
Solar wind streams flowing from the indicated coronal holes could brush against Earth’s magnetic field on Sept. 16-17. Credit: NASA/SDO.Noctilucent Clouds NASA’s AIM spacecraft has suffered an anomaly, and a software patch is required to fix it. As a result, current noctilucent cloud images will not return until late September 2016.
Switch view: Europe, USA, Asia, PolarUpdated at: 08-06-2016 16:55:02
Updated at: 2016 Sep 14 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Sep 14 2200 UTCMid-latitudes