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 07 Aug 2015
Planetary K-index Now: Kp= 2 quiet 24-hr max: Kp= 5 storm explanation | more data
Interplanetary Mag. Field Btotal: 8.2 nT Bz: 0.5 nT north explanation | more data Updated: Today at 2348 UT
Coronal Holes: 07 Aug 15
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
Noctilucent CloudsThe northern season for NLCs is underway. NASA's AIM spacecraft spotted the first noctilucent clouds over the Arctic Circle on May 19th.
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 Aug 07 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
35 %
35 %
MINOR
15 %
25 %
SEVERE
01 %
05 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
10 %
MINOR
30 %
25 %
SEVERE
50 %
55 %
Friday, Aug. 7, 2015
What's up in space
Come to Tromsø and share Marianne's passion for rural photography: Chasethelighttours.co.uk invites you to experience "Heaven on Earth" with an aurora, fjord, fishing, whale watching, photography or sightseeing tour.
GEOMAGNETIC STORM: A minor (Kp=5) geomagnetic storm is underway on Aug. 7th as a high-speed solar wind stream buffets Earth's magnetic field. High-latitude sky watchers should be alert for auroras, especially during the hours around local midnight. [forecast video] Aurora alerts: text or voice.
BIG SUNSPOT TURNS TOWARD EARTH: What a difference a few days can make. Earlier this week, sunspot AR2396 was completely invisible. Now it has grown into a behemoth more than 120,000 km wide. Francois Rouviere sends this picture from Mougins, France:
All by itself, the primary dark core in Rouviere's image is twice the size of Earth. These dimensions make the sunspot an easy target for backyard solar telescopes.
Amateur astronomers are encouraged to monitor developments around this active region. With an unstable 'beta-gamma' magnetic field, it is crackling with C-class solar flares and could unleash an even stronger M-flare as it approaches the center of the solar disk. Any such eruption in the days ahead will almost surely be geoeffective. Solar flare alerts: text or voice.
YES, THIS IS REAL: NOAA's Deep Space Climate Observatory (DSCOVR), on a mission to monitor the solar wind a million miles from Earth, has taken a unique picture of the Earth-Moon system. It shows the farside of the Moon crossing the iconic "blue marble" on July 16th. Click to witness the transit:
DSCOVR is a partnership between NOAA, NASA, and the U.S. Air Force. The July 16th images were captured by NASA's Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope onboard the distant observatory.
Because the Moon is tidally locked to Earth, only one side is visible from our planet. The unseen farside of the Moon was shrouded in mystery until 1959 when the Soviet Luna 3 spacecraft swung around the Moon and photographed it for the first time. DSCOVR will repeat the trick about twice a year as observatory periodically crosses the orbital plane of the Moon.
Once EPIC begins regular observations next month, NASA will post daily color images of Earth to a dedicated public website. These images, showing different views of the planet as it rotates through the day, will be available 12 to 36 hours after they are acquired. Read the NASA press release for more information.
PERSEID FIREBALLS: Earth is entering a stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Peak rates of 100+ meteors per hour are expected next week when Earth approaches the heart of the debris stream. The display, however, is already underway. "Our network of meteor cameras has picked up more than 78 Perseid fireballs since July 27th," reports Bill Cooke of NASA's Meteoroid Environment Office. He prepared this solar system diagram showing the orbits of all the fireballs so far:
The green ellipses trace the orbits of Perseid meteoroids. They are a good match to the orbit of the parent comet, shown in purple.
"Comet debris particles a few cm wide are hitting the atmosphere with an average speed of 59.6 km/s (133,350 mph)," continues Cooke. "The average magnitude of the resulting fireballs is -3.7, about as bright as Venus."
Cooke and colleagues have been monitoring fireball activity for years, and they have found that the Perseids produce more fireballs than any other annual shower. Check out their data.
"Comet Swift-Tuttle has a huge nucleus--about 26 km in diameter," notes Cooke. "Most other comets are much smaller, with nuclei only a few kilometers across. As a result, Comet Swift-Tuttle produces a large number of meteoroids, many of which are hefty enough to produce fireballs."
More fireballs are in the offing as Earth moves deeper into the debris stream of Comet Swift-Tuttle. Stay tuned!
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. 7, 2015, the network reported 32 fireballs. (22 sporadics, 9 Perseids, 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 7, 2015 there were potentially hazardous asteroids.
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.
