Space Weather Update: 08/17/2016
By Spaceweather.com, 08/17/2016
SOMETHING FISHY: According to folklore, this weekend’s full Moon is the Sturgeon Moon, named by Native American tribes of the Great Lakes who caught lots of sturgeon during the month of August. A Moon named after an ancient bony fish? Go outside and take a look. It’s prettier than it sounds: photo gallery.
RETURN OF THE NORTHERN LIGHTS: During the early hours of August 17th, a solar wind stream passed to the south of Earth. The near-miss disturbed our planet’s magnetic field, sparking auroras around the Arctic Circle. In Handöl, Sweden, photographer Göran Strand saw Northern Lights for the first time in months:
“Finally, aurora season begins after a summer of midnight suns,” says Strand. “In a couple of weeks we will have darker astronomical nights, and the displays will be even better. The landscape was nicely illuminated by the 96% waxing full Moon.”
SPACE LIGHTNING OVER CHINA: On Aug. 13th in China, photographer Phebe Pan was photographing the night sky, hoping to catch a Perseid meteor. Instead, he witnessed a spectacular bolt of “space lightning.” Working atop Shi Keng Kong, the highest mountain peak in the Guangdong province, “I was using a fisheye lens to capture as much of the sky as possible,” says Pan. “Suddenly we saw a flash of blue and purple ejected from the top of a nearby thundercloud. It just looked like a tree with branches, and grew up very fast. So awesome!”
“It just looked like a tree with branches, and grew up very fast,” says Pan. “It lasted just less than one second. So awesome!”
Oscar van der Velde, a member of the Lightning Research Group at the Universitat Politècnica de Catalunya, explains what Pan saw: “This is a very lucky capture of a gigantic jet. It’s the first time I’ve seen one captured using a fisheye lens!”
Think of them as sprites on steroids: Gigantic jets are lightning-like discharges that spring from the tops of thunderstorms, reaching all the way to the ionosphere more than 50 miles overhead. They’re enormous and powerful.
“Gigantic jets are much more rare than sprites,” says van der Velde. “While sprites were discovered in 1989 and have since been photographed by the thousands, it was not until 2001-2002 that gigantic jets were first recorded from Puerto Rico and Taiwan.” Only a few dozen gigantic jets have ever been seen.
Like their cousins the sprites, gigantic jets reach all the way up to the edge of space alongside meteors, noctilucent clouds, and some auroras. This means they are a true space weather phenomenon. Indeed, some researchers believe cosmic rays help trigger these exotic forms of lightning, but the link is controversial.
INTERCONTINENTAL BALLOON NETWORK: Aug 21, 2016, is an important date. It’s the one year pre-anniversary of the Great American Solar Eclipse. On Aug. 21, 2017, the Moon will pass in front of the sun, producing a total eclipse visible from coast to coast in the USA. To record the eclipse as never before, Spaceweather.com and the students of Earth to Sky Calculus will lead more than a dozen teams of citizen scientists in launching balloons through the path of totality. Our goal: to photograph the eclipse from the stratosphere and create a unique movie of the Moon’s shadow sweeping across the continent. Such an ambitious project requires practice, and we’re starting now:
For the next month, we’ll be launching groups of balloons from multiple sites around North and South America. Each site (including the one in Chile) will be crewed by students and teachers involved in the Solar Eclipse Balloon Network. Launching large numbers of balloons simultaneously is a key logistical challenge for the 2017 eclipse, and this will be good practice indeed. The first launch on Aug. 21st will involve as many as four balloons lifting off from Chile, California, Oregon and Illinois.
Because our standard eclipse payload includes radiation sensors, we will be learning a great deal about the geographical distribution of cosmic rays in Earth’s atmosphere. The Chilean launch, in particular, promises interesting results as it occurs directly beneath the South Atlantic Anomaly. Stay tuned!
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 Aug. 17, 2016, the network reported 178 fireballs.
(170 sporadics, 5 Perseids, 2 , 1 kappa Cygnid)
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 August 17, 2016 there were 1726 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: 374.7 km/sec
density: 2.8 protons/cm3
explanation | more data
Updated: Today at 2123 UTX-ray Solar Flares
6-hr max: B1 1758 UT Aug17
24-hr: B3 1001 UT Aug17
explanation | more data
Updated: Today at: 2100 UTDaily Sun: 17 Aug 16Not one of these sunspots has the type of unstable magnetic field that poses a threat for strong flares. Credit: SDO/HMI
Sunspot number: 81
What is the sunspot number?
Updated 17 Aug 2016
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 17 Aug 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 3 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 7.4 nT
Bz: 1.7 nT north
explanation | more data
Updated: Today at 2123 UTCoronal Holes: 17 Aug 16
There are no large coronal holes on he Earth-facing side of the sun. Credit: NASA/SDO.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: 08-06-2016 16:55:02
Updated at: 2016 Aug 16 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Aug 16 2200 UTCMid-latitudes