Space Weather Update: 06/02/2016
By Spaceweather.com, 06/02/2016
WEEKEND STORMS ARE LIKELY: NOAA forecasters estimate a 75% chance of geomagnetic storms on June 4th and 5th when a solar wind stream hits Earth’s magnetic field. Deja vu? This stream has been here before. On May 8th (Mother’s Day), it sparked the strongest geomagnetic storm of 2016. During that G3-classevent, auroras were photographed in the USA as far south as Kansas and Arkansas. This time, analysts expect the storm to peak at G2–not as strong as the Mother’s Day Storm, but still worth watching. High-latitude sky watchers should be alert for auroras,especially in the southern hemisphere where darkening autumn skies favor visibility. Aurora alerts: text, voice.
ASTEROID EXPLODES OVER ARIZONA: Early this morning, June 2nd just before 4 a.m. MST, a small asteroid hit Earth’s atmosphere and exploded over Arizona. “There was a bright flash and the ground shook from the explosion,” reports Chris Schur of Payson AZ, who says the flash of light was about 10x brighter than a full Moon. The explosion actually blinded a NASA camera located at the Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona:
Watch the complete movie to get a sense of how bright the fireball was. The fact that the explosion saturated most cameras that saw it initially complicated analysts’ efforts to pinpoint its nature and origin.
Schur missed photographing the explosion itself, but “we were able to get images soon after of the smoke train from this object.” Here it is, twisting in the winds of the upper atmosphere before sunrise:
Bill Cooke of NASA’s Meteoroid Environment Office says this is the brightest fireball detected in the 8-year history of the NASA’s All Sky Fireball Network, an array of cameras that monitors fireball activity across the USA. According to NASA analysts, the asteroid was ~10 feet (3 meters) in diameter with a mass in the tens of tons and a kinetic energy of approximately 10 kilotons.
Eyewitness reports placed the object at an altitude of 57 miles above the Tonto National Forest east of the town of Payson, moving almost due south. It was last seen at an altitude of 22 miles above that same forest.
“There are no reports of any damage or injuries—just a lot of light and few sonic booms,” says Cooke. “If Doppler radar is any indication, there are almost certainly meteorites scattered on the ground north of Tucson.”
WHERE THE SOLAR WIND COMES FROM…. The incoming solar wind stream, discussed above in the weekend forecast, is flowing from a coronal hole on the sun:
Image credit: NASA’s Solar Dynamics Observatory
Coronal holes are places in the sun’s atmosphere where the sun’s magnetic field opens up and allows solar wind to escape. Coronal holes are akin to a lighthouse. They strobe Earth with streams of solar wind every 27 days, the rotation period of the sun. The last time this particular hole strobed Earth was in early May when it set the stage for the Mother’s Day Storm. Will June be as stormy? Monitor the gallery for aurora sightings:
POLLEN CORONAS: It begins with a sneeze. Pollen floating through the air tickles your nose, and your body responds by expelling the allergen. Gesundheit! When the paroxysm subsides, look up at the sky. The same pollen that makes you sneeze can also make beautiful coronas around the sun, like this one photographed on June 1st by Vesa Vauhkonen of Rautalampi, Finland:
“Pine is strongly flowering now in middle Finland, and the coronas have been quite impressive over the past few days,” says Vauhkonen. “Pollen is everywhere–not only in noses and eyes, but also around the setting sun.”
Atmospheric optics expert Les Cowley explains the phenonenon: “Coronas are produced when light waves scatter from the outsides of small particles. Tiny droplets of water in clouds make most coronas, but opaque equal-sized pollen grains do even better. They make small but very colorful multi-ringed coronas.”
“Unlike water droplets, pollens are non-spherical–and this adds to their magic,” he continues. “Many have air sacs to help carry them in the wind. These align the grains to give beautiful elliptical coronas with bright spots.” This is why Vauhkonen’s pollen corona looks the way it does.
As northern spring turns into summer, pollen coronas become increasingly common. Look for them the next time your nose feels a tickle.
SPACE BEARS MAKE GOOD GRADUATION GIFTS: Around the USA, high school seniors are preparing to receive their diplomas. Nothing says “you’re on your way up!” better than a graduation gift from the Edge of Space. On May 25th, the students of Earth to Sky Calculus flew a family of “graduation grizzlies” 27 km (90,000 feet) above Earth’s surface:
Outfitted with space helmets and a diploma, the intrepid Ursidae survived cosmic rays, ultra-low temperatures, and the near-vacuum of the stratosphere. For $49.95 you can have one of these bears along with a unique Graduation card showing the bears floating at the top of Earth’s atmosphere. Buy one now.
Sales of the bears support student space weather research. In fact, the bears pictured above were hitchhiking on a payload equipped with radiation sensors. We send the sensors to the stratosphere every week to monitor increasing levels of cosmic rays. Visit the Earth to Sky store to support this crowd-funded research.
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 Jun. 2, 2016, the network reported 21 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 June 2, 2016 there were 1702 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: 335.2 km/sec
density: 3.5 protons/cm3
explanation | more data
Updated: Today at 2101 UTX-ray Solar Flares
6-hr max: B2 1636 UT Jun02
24-hr: B2 0000 UT Jun02
explanation | more data
Updated: Today at: 2000 UTDaily Sun: 02 Jun 16Neither of these sunspots pose a threat for strong flares. Solar activity remains low. Credit: SDO/HMI
Sunspot number: 30
What is the sunspot number?
Updated 02 Jun 2016
Current Stretch: 0 days
2016 total: 0 days (0%)
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 02 Jun 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: 3.6 nT
Bz: 0.6 nT south
explanation | more data
Updated: Today at 2100 UTCoronal Holes: 02 Jun 16Solar wind flowing from the indicated coronal hole could reach Earth on June 4th. 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: 06-02-2016 15:55:03
Updated at: 2016 Jun 01 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Jun 01 2200 UTCMid-latitudes