ARCTIC AURORAS LIKELY THIS WEEK: An irregular hole in the sun's atmosphere is spewing a stream of solar wind toward Earth. Estimated time of arrival: Oct. 24th. High-latitude sky watchers should be alert for auroras when the gaseous material arrives. A bright full Moon on Oct. 24th will add its luminosity to that of any geomagnetic storm, creating some nice landscape photo-ops around the Arctic Circle. Free: Aurora Alerts.
SOMETHING WICKED-GREEN THIS WAY COMES: A green ball of gas wider than the planet Jupiter is approaching Earth. It's name is "Comet 46P/Wirtanen." Italian astronomer Rolando Ligustri photographed the verdant orb on Oct. 18th using a remote-controlled telescope in Australia:
Deep inside that green ball is a furiously vaporizing nugget of dirty ice. The frozen nucleus of 46P/Wirtanen is only about 1 km wide, but astronomers say it is "hyperactive." As many as 1.7×1028 water molecules per second have been observed emerging from the comet's core. Mixed with the water vapor is diatomic carbon (C2)--a gaseous substance common in comet atmospheres that glows green in the near-vacuum of space.
On Dec. 16th, this hyperactive comet will come within 11.5 million km of Earth--making it one of the 10 closest-approaching comets of the Space Age. Comet 46P/Wirtanen will probably become a naked eye object for several weeks during the holidays, prompting some astronomers to call it "the Comet of the Year."
Comet Wirtanen passes through the inner solar system every 5.4 years. Right now it is near the orbit of Mars, and it is heading in our direction. Forecasters expected it to brighten more than 200-fold between now and mid-December, eventually reaching magnitude +3, similar to the stars of the Pleiades. Stay tuned.
Are you new to comet photography? Get Astro-imaging Tutorials from award-winning astrophotographer Damian Peach.
More resources: sky map; ephemeris; 3D orbit; light curve.
FLY ME TO THE MOONSTONE: Are you looking for a far-out gift? Nothing says "I love you" like a moonstone from the edge of space. On Jan 27th, the students of Earth to Sky Calculus flew this moonstone wrapped in a hand-crafted sterling silver Celtic love knot 35.1 km (115,158 feet) above Earth's surface:
You can have it for $179.95. The students are selling these pendants to support their cosmic ray ballooning program. Each one comes with a greeting card showing the item in flight and telling the story of its journey to the edge of space. All sales support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Space Weather Photo Gallery