Spotless Days 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 25 Mar 2016
Geomagnetic Storms: Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2016 Mar 25 2200 UTC
Friday, Mar. 25, 2016
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.
VERY QUIET SUN: Solar activity has returned to very low levels, and it is likely to remain so for the next few days. NOAA forecasters say there is no more than a 1% chance of strong flares on March 25-26-27. Solar flare alerts: text or voice
RADAR IMAGES OF EARTH-BUZZING COMET: On March 22nd, comet fragment P/2016 BA14 made the 3rd-closest approach to Earth of any comet in recorded history. NASA researchers took advantage of the comet's proximity and pinged its icy core using the Goldstone Solar System Radar in California's Mojave Desert. Newly released images reveal a 1-km wide strangely-shaped object spinning once every 35 to 40 hours:
"The comet has an irregular shape. It looks like a brick on one side and a pear on the other," says Shantanu Naidu, a postdoctoral researcher at NASA's Jet Propulsion Laboratory who led the observations. "We can see quite a few signatures related to topographic features such as large flat regions, small concavities and ridges on the surface of the nucleus."
While the radar observations were underway, Vishnu Reddy of the Planetary Science Institute in Tucson, Arizona, also observed P/2016 BA14 using the Infrared Telescope Facility on Mauna Kea, Hawaii. He found that the comet reflects less than 3 percent of the sunlight that falls on its surface. In other words, it was as dark as fresh asphalt.
CORONAL CANYON SPEWS SOLAR WIND: A gaseous canyon has opened up in the sun's atmosphere, and it is spewing solar wind toward Earth. NASA's Solar Dynamics Observatory is monitoring the structure, shown here in an extreme ultraviolet image taken on March 25th:
This is a canyon-shaped example of a coronal hole--a place in the sun's atmosphere where the magnetic field spreads apart and allows solar wind to escape. In the image, above, the coronal hole is colored deep-blue, while the flow of solar wind is indicted by white arrows.
A stream of solar wind flowing from the canyon should reach Earth on March 28th. There's a good chance its arrival will bring auroras. The reason is, the stream will be preceded by a co-rotating interaction region or "CIR." CIRs are transition zones between slow- and fast-moving solar wind streams. Solar wind plasma piles up in these regions, producing density gradients and shock waves that do a good job of sparking Northern Lights. Aurora alerts: text or voice
PLANT YOUR OWN SPACE GARDEN: Northern spring has arrived, and that means it's time to plant flowers. Mutant space flowers, that is. These Zinnia seeds flew to the edge of space aboard an Earth to Sky Calculus helium balloon on Feb. 17, 2016:
En route, the seeds were exposed to comic ray doses more than 100x Earth normal, temperatures as low as -63C, and air pressures only 0.3% of sea level.
Zinnias are interesting because they have recently blossomed on the International Space Station. Maybe it's time to plant these space flowers in your garden, too. For $49.95 you can have some. Each order comes with one seed packet flown to the edge of space, and a second seed packet that was kept on Earth as a control sample. Plant them side by side to discover the effect of near-space flight on your flowers. All proceeds support student research.
Speaking of mutants, we have also flown sunflower seeds to the edge of space, where they soaked up cosmic rays for more than 2 hours. What happens when you plant such seeds? Spaceweather.com reader Christian Schwarze bought some and found out. "A second flower grew out of the side of the first one," he says. "Very strange!"
"Unfortunately, we were on holiday while it flowered," says Schwarze.
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 Mar. 25, 2016, the network reported 8 fireballs. (8 sporadics)
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 March 25, 2016 there were potentially hazardous asteroids.
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.