Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift. | | |
STORM WARNING: A fast-moving stream of solar wind is buffeting Earth's magnetic field. The combined effect of this stream plus a CME expected to arrive on June 24th has prompted NOAA forecasters to declare a 30% to 35% chance of geomagnetic storms during the next 24 hours. High-latitude sky watchers should be alert for auroras.
ASTEROID FLYBY: Newly-discovered asteroid 2011 MD will pass only 12,000 kilometers (7,500 miles) above Earth's surface on Monday June 27 at about 9:30 a.m. EDT. NASA analysts say there is no chance the space rock will strike Earth. Nevertheless, the encounter is so close that Earth's gravity will sharply alter the asteroid's trajectory:
At closest approach, 2011 MD will pass in broad daylight over the southern Atlantic Ocean near the coast of Antarctica. As the asteroid recedes from Earth, it will pass through the zone of geosynchronous satellites. The chances of a collision with a satellite or manmade space junk are extremely small, albeit not zero.
Judging from the brightness of the asteroid, it measures only 5 to 20 meters in diameter. According to JPL's Near Earth Object Program office, one would expect an object of this size to come this close to Earth about every 6 years on average. For a brief time, it will be bright enough to be seen even with a medium-sized backyard telescope. [observing tips] [3D orbit]
SUNSPOT VS. WILDFIRE: On June 21st, while working a raging wildfire in north Florida, medivac pilot Chris Lambert looked up at the sun and saw a dark spot through the smoke. "Was it a transit of Mercury?" He emailed the question to his friend, solar photographer Stephen W. Ramsden. "I knew exactly what he was looking at," says Ramsden, "because I had been imaging it all week at public astronomy events in Atlanta." It was sunspot AR1236:
"I explained to Chris that he was simply using the ancient Chinese method of watching the sun through thick smoke or at sunrise and sunset in order to record these giant islands of magnetism on the sun's surface," continues Ramsden. "I sent him back a closeup photo that I had taken earlier that morning of the same feature. Good luck to Chris and all the firefighters risking their lives around the country to fight these epic blazes."
more images: from Jerry Dzuricky of Erie, PA; from Piet Berger of Eys, The Netherlands; from Charles Beanland at the Bay of Gibraltar, Europe;
June 2011 Aurora Gallery
[Aurora alerts: text, voice] [previous Junes: 2010, 2008, 2001]
June 15th Lunar Eclipse Gallery
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 June 24, 2011 there were 1237 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Mag. | Size |
2011 MD | Jun 27 | 0.05 LD | -- | 11 m |
2011 GA55 | Jul 6 | 64.1 LD | -- | 1.0 km |
2011 EZ78 | Jul 10 | 37.3 LD | -- | 1.6 km |
2003 YS117 | Jul 14 | 73.9 LD | -- | 1.0 km |
2007 DD | Jul 23 | 9.3 LD | -- | 31 m |
2009 AV | Aug 22 | 49.7 LD | -- | 1.1 km |
2003 QC10 | Sep 18 | 50 LD | -- | 1.2 km |
2004 SV55 | Sep 19 | 67.5 LD | -- | 1.2 km |
2007 TD | Sep 23 | 3.8 LD | -- | 58 m |
2002 AG29 | Oct 9 | 77.1 LD | -- | 1.0 km |
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 |
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