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ANTARCTIC MICROBES LAUNCHED TO THE STRATOSPHERE: On Saturday, May 30th, Spaceweather.com and the students of Earth to Sky Calculus launched approximately 100 billion microbes from Antarctica to the stratosphere. During the 3 hour flight, which skirted the edge of space, the extremophiles were exposed to extreme cold (-60 C) and doses of cosmic radiation more than 100x Earth-normal. Did they survive? Stay tuned for updates.
A CLOSER LOOK AT THE SURFACE OF THE SUN: At times of low sunspot number, we say "the sun is nearly blank." Now is such a time. This weekend, however, amateur astronomer Christian Viladrich of Nattages, France, took a closer look at the surface of the spotless sun. It was anything but blank:
In the field of view of his 12 inch telescope (solar-filtered), he could see thousands of roiling bubbles. The sample, above, is just a fraction of what he saw. Click here for thousands more.
These are not sunspots, but rather granules. The sun is so hot, it literally boils. Granules are bumps on the boiling surface, much like the bumpy surface of water boiling on a hot stove. One difference: While the granules on your stove are only a few centimeters across, granules on the sun are as wide as Texas.
So much for the "blank sun." Solar flare alerts: text, voice
Realtime Space Weather Photo Gallery
NOCTILUCENT CLOUDS INTENSIFY: The northern summer season for noctilucent clouds (NLCs) is underway. Earth-orbiting satellites such as AIM and the International Space Station have been photographing the electric-blue clouds for days. On May 28th, sky watchers on Earth saw them, too. Andy Stables sends this picture from Isle of Skye, Scotland.
The fine-structured blue clouds floating above the dark, ordinary storm clouds are the NLCs. "The NLCs were coming through the twilight at 00:25 UT with some really nice ripple structures,"says Stables. They stretched about 15 degrees above the horizon."
NLCs are Earth's highest clouds. Seeded by meteoroids, they float at the edge of space more than 80 km above the planet's surface. The clouds are very cold and filled with tiny ice crystals. When sunbeams hit those crystals, they glow electric-blue.
Noctilucent clouds first appeared in the 19th century after the eruption of super-volcano Krakatoa. At the time, people thought NLCs were caused by the eruption, but long after Krakatoa's ash settled, the clouds remained. In recent years, NLCs have intensified and spread with sightings as far south as Utah and Colorado. This could be a sign of increasing greenhouse gases in Earth's atmosphere.
Observing tips: Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
Realtime NLC Photo Gallery
RADAR ECHOES FROM THE NOCTILUCENT ZONE: Every summer since the late 1970s, radars probing Earth's upper atmosphere have detected strong echoes from altitudes between 80 km and 90 km. These altitudes comprise the "noctilucent zone," where water vapor crystallizes around meteor smoke to form icy noctilucent clouds (NLCs). The first NLCs of the 2015 northern summer season were spotted by NASA's AIM spacecraft on May 19th. The radar echoes have followed close behind.
Les Dean of the MST Radar Facility in Aberystwyth, Wales, reports: "We detected our first echoes of the summer season on May 26th."
Researchers call them "Polar Mesospheric Summer Echoes" or "PMSEs." They occur over the Arctic during the months of May through August, and over the Antarctic during the months of November through February. These are the same months that NLCs appear.
But do the radar echoes actually come from noctilucent clouds? "The association is controversial," notes Dean. A leading theory holds that the ice particles in noctilucent clouds are electrically charged, and this makes them good reflectors of HF radio waves. However, NLCs are not always visible when the radar echoes are observed and vice versa. So the connection is not clear-cut.
One thing is sure: the northern season for both NLCs and PMSEs has begun. Stay tuned for more echoes from the noctilucent zone.
UPDATE: "What is happening 90 km above Earth's surface?" wonders researcher Rob Stammes at the Polarlightcenter in Lofoten, Norway. For the past two nights, he has detected intense radio reflections using a forward scatter meteor radar. The phenomenon is almost surely linked to the PMSEs and noctilucent clouds reported above.
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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 May. 31, 2015, the network reported 7 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]
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 May 31, 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.
| ||The official U.S. government space weather bureau |
| ||The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| ||Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| ||3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| ||Realtime and archival images of the Sun from SOHO. |
| ||from the NOAA Space Environment Center |
| ||the underlying science of space weather |