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 01 Sep 2015
Planetary K-index Now: Kp= 1 quiet 24-hr max: Kp= 2 quiet explanation | more data
Interplanetary Mag. Field Btotal: 5.1 nT Bz: 1.3 nT south explanation | more data Updated: Today at 2018 UT
Coronal Holes: 01 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 CloudsThe 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.
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 %
Tuesday, Sep. 1, 2015
What's up in space
Marianne's Heaven On Earth Aurora Chaser Tours Chasethelighttours.co.uk invites you to join them in their quest to find and photograph the Aurora Borealis. Experience the winter wonderland in the Tromsø Area.
SOLAR SECTOR BOUNDARY CROSSNG: 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 70% chance of polar geomagnetic storms when it occurs. Aurora alerts: text or voice
ALMOST-BLANK SUN: The sunspot number is plummeting, and the Earth-facing side of the sun is almost blank. Scan this image, taken on Sept. 1st by NASA's Solar Dynamics Observatory, to see how many dark cores you can find:
There are only a few tiny spots, circled here. Not one of them has the type of unstable magnetic field that harbors energy for strong flares. As a result, the sun's X-ray output is flatlining. NOAA forecasters estimate a 5% chance of M-flares and no more than a 1% chance of X-flares during the next 24 hours. Solar flare alerts: text or voice
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.
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.
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. 1, 2015, the network reported 51 fireballs. (50 sporadics, 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 1, 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.
