LOST ASTEROID RETURNS TO EARTH: In Nov. 2010, the Catalina Sky Survey in Arizona discovered a near-Earth asteroid as wide as a football field. Before astronomers could fully trace its orbit, however, the receding space rock faded away. It has been lost ever since--that is, until last week when it reappeared, approaching Earth.
The name of the asteroid is 2010 WC9. Marian Urbanik of Čadca, Slovakia, photographed it on May 12th--a barely visible 17th magnitude speck in the constellation Hercules:
It is about to get much closer and brighter. On May 15th 2010 WC9 will fly past our planet, splitting the distance between Earth and the Moon. At closest approach (203,000 km), it will glow like an 11th magnitude star (~250 times brighter than shown above) as it races through the southern constellation Pavo.
Estimates of 2010 WC9's size range from 60 m to 130 m wide. This puts it in the class of the Tunguska impactor, which leveled a forest in Siberia in 1908. And it is at least 3 times as large as the Chelyabinsk meteoroid, which exploded in the morning sky over Russia on Feb. 15, 2013, shattering windows and knocking people to the ground
There's no danger of a collision this time, though. Analysts are certain 2010 WC9 will not hit Earth--neither this week nor in the foreseeable future. New observations of the asteroid in recent days have extended our knowledge of its orbit and eliminated it as a threat for at least the next 100 years.
2010 WC9 is invisible to the naked eye. Advanced amateur astronomers can photograph it, however, using mid-sized telescopes equipped with low-light video cameras. Southern hemisphere observers are favored, expecially those in South Africa and southern parts of South America where the asteroid will be high in the night sky at closest approach. [ephemeris] [3D orbit]
Realtime Space Weather Photo Gallery
GEOMAGNETIC STORMS POSSIBLE LATER THIS WEEK: NOAA forecasters say that polar geomagnetic storms are possible on May 17th when a stream of solar wind reaches Earth. The gaseous material is flowing from a southern hole in the sun's atmosphere, shown here in a false-color UV image from NASA's Solar Dynamics Observatory:
This is a coronal hole--a place where the sun's magnetic field opens up and allows solar wind to escape. Coronal holes look dark because hot glowing gas normally contained there is missing.
Previous encounters with solar wind from this coronal hole suggest that storm levels could reach category G2 when the fast-moving stream arrives, although a lesser G1 storm is more likely.. High latitude sky watchers should be alert for auroras and, of course, STEVE. Free: Aurora Alerts.
3D GLOWING MOON GLOBE: Are you looking for a far-out gift? Consider this: In January, the students of Earth to Sky Calculus flew a glowing 3D printed Moon globe to the stratosphere:
You can have it for $149.95. The students are selling these unique globes as a fundraiser for their cosmic ray monitoring program.
The surface of the sphere is an accurate topo-map of lunar terrain, tracing every major crater and mountain range. It is also a night light. A built-in USB-rechargeable battery provides up to 20 hours of illumination.
Each glowing orb comes with a greeting card showing the Moon in flight and telling the story of its journey to the edge of space. All proceeds support Earth to Sky Calculus and hands-on STEM research.
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education