By Spaceweather.com, 09/02/2015
SOLAR SECTOR BOUNDARY CROSSING: High-latitude auroras are possible on Sept. 2nd when Earth crosses through a fold in the heliospheric current sheet. This is called a “solar sector boundary crossing,” and NOAA forecasters estimate a 60% chance of polar geomagnetic storms when it occurs. Aurora alerts: text or voice
156 YEARS AGO, A GEOMAGNETIC MEGA-STORM: On Sept. 2nd, a billion-ton coronal mass ejection (CME) slammed into Earth’s magnetic field. Campers in the Rocky Mountains woke up in the middle of the night, thinking that the glow they saw was sunrise. No, it was the Northern Lights. People in Cuba read their morning paper by the red illumination of aurora borealis. Earth was peppered by particles so energetic, they altered the chemistry of polar ice.
Hard to believe? It really happened–exactly 156 years ago. This map shows where auroras were sighted in the early hours of Sept. 2, 1859:
As the day unfolded, the gathering storm electrified telegraph lines, shocking technicians and setting their telegraph papers on fire. The “Victorian Internet” was knocked offline. Magnetometers around the world recorded strong disturbances in the planetary magnetic field for more than a week.
The cause of all this was an extraordinary solar flare witnessed the day before by British astronomer Richard Carrington. His sighting marked the discovery of solar flares and foreshadowed a new field of study: space weather. According to the National Academy of Sciences, if a similar storm occurred today, it would cause a trillion dollars in damage to society’s high-tech infrastructure and require four to ten years for complete recovery.
In fact, a similar flare did occur just a few years ago. On July 23, 2012, a CME of rare power rocketed away from the sun. The storm was in all respects at least as strong as the 1859 Carrington event. The only difference is, it missed. no harm done. The July 2012 event serves as a reminder, however, that extreme space weather is not a thing of the past.
Realtime Space Weather Photo Gallery
SPACE STATION TRANSITS A PROMINENCE: In recent years, astrophotographers have become increasingly adept at catching the International Space Station during split-second transits of the sun. The winged form of the behemoth spaceship looks beautiful when backlit by fiery plasma, and on more than one occasion it has been seen in conjunction with active sunspots. Now, for perhaps the first time, Thierry Legault of Paris, France, has captured the silhouette of the ISS passing in front of a solar prominence:
“This was no accident,” says Legault. “Using Calsky to predict the circumstances of the transit, I positioned my telescope 1 mile north of the central transit line so that the ISS would pass directly between me and the prominence.”
His pinpoint preparations worked, and he captured more than 30 video frames of the ISS zooming across the face of the sun. The complete crossing may be seen on Youtube.
Solar observers are paying extra attention to prominences this week because that is almost the only thing to see. With only a few small sunspots dotting the solar disk, the face of the sun is nearly featureless. Plumes of plasma rising over the sun’s limb are the photo-op du jure–even better when a spaceship joins the show.
Realtime Space Weather Photo Gallery
THE SPACE PIZZA EXPERIMENT: Regular readers of Spaceweather.com know that we have been flying colonies of yeast to the edge of space to study the effect of cosmic rays on their biology. But yeast aren’t just for science. They also make great pizza. To support our program, Emily Winter purchased some yeast packets from the stratosphere, and she has a report to share: “My friends and I made a pizza with your space yeast. We had so much fun!” Their video is a must-see:
The yeast packets Emily and her friends used to bake “space pizza” were exposed to extreme conditions in the stratosphere: air pressures less than 1% of sea level, temperatures as low as -60 C, and cosmic ray dose rates nearly 100x Earth-normal. Despite this harsh treatment, the yeast returned to Earth with more than enough vitality to puff up a delicious pizza crust. This is in accord with our scientific measurements of yeast survival rates–in some cases greater than 90%. The microbes are extremely tough and can easily survive near-space travel.
Emily and friends say the space pizza tasted much like normal pizza, but it did have an unexpected side effect. Watch the video all the way to the end for their revelation.
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. 2, 2015, the network reported 11 fireballs.
(8 sporadics, 2 Northern iota Aquariids, 1 alpha Aurigid)
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 2, 2015 there were 1607 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2015 QT3
Aug 28
4.2 LD
71 m
2015 PT227
Aug 29
9.7 LD
69 m
2004 BO41
Aug 31
57.3 LD
1.2 km
1991 CS
Sep 4
62.1 LD
1.4 km
2014 KS76
Sep 14
8.7 LD
22 m
2004 TR12
Sep 15
58.8 LD
1.0 km
2000 FL10
Oct 10
65.7 LD
1.9 km
2011 QD48
Oct 17
67.5 LD
1.0 km
2014 UR
Oct 18
3.8 LD
21 m
2011 SE97
Oct 18
12 LD
50 m
2001 UY4
Oct 21
58.2 LD
1.0 km
2005 UL5
Nov 20
5.9 LD
390 m
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.
Current Conditions
Solar wind
speed: 382.5 km/sec
density: 12.6 protons/cm3
explanation | more data
Updated: Today at 1500 UT
X-ray Solar Flares
6-hr max: B5 0755 UT Sep02
24-hr: B5 0755 UT Sep02
explanation | more data
Updated: Today at: 1400 UT
Daily Sun: 02 Sep 15
With only a few small sunspots dotting the solar disk, solar activity is very low.. Credit: SDO/HMI
Sunspot number: 49
What is the sunspot number?
Updated 02 Sep 2015
Spotless Days
Current Stretch: 0 days
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 Sep 2015
The Radio Sun
10.7 cm flux: 89 sfu
explanation | more data
Updated 02 Sep 2015
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 4.5 nT
Bz: 2.7 nT north
explanation | more data
Updated: Today at 1500 UT
Coronal Holes: 02 Sept. 15
A stream of solar wind flowing from the indicated coronal hole should reach Earth on or about Sept. 3rd. Credit: SDO/AIA.
Noctilucent Clouds
The northern season for NLCs is finished. According to NASA’s AIM spacecraft, the last clouds were observed over Greenland on Aug. 27th. Now the waiting begins for the southern season to begin sometime in November.
Switch view: Europe, USA, Asia, Polar
Updated at: 09-01-2015 09:00:00
NOAA Forecasts
Updated at: 2015 Sep 01 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
01 %
01 %
CLASS X
01 %
01 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2015 Sep 01 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
40 %
30 %
MINOR
25 %
15 %
SEVERE
05 %
05 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
25 %
25 %
SEVERE
60 %
50 %
Space Weather Update: 09/02/2015
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