CHANCE OF STORMS THIS WEEK: NOAA forecasters estimate a 40% chance of polar magnetic storms on Feb. 7th when Earth crosses through a fold in the heliospheric current sheet--a giant rippling system of electrical currents in space. Not long after the crossing, perhaps on Feb. 8th, a stream of solar wind is expected to hit our planet's magnetic field. The source of the stream is a hole in the sun's atmosphere. The combination of these two events will likely spark bright Arctic auroras mid-week. Free: Aurora alerts.
GREEN COMET APPROACHES EARTH: A small comet named "45P/Honda-Mrkos-Pajdusakova" (45P for short) is approaching Earth. At closest approach on Feb. 11th, the comet will be 7.4 million miles from our planet, visible in binoculars and small telescopes. This is what it looks like:
Michael Jäger of Stixendorf, Austria, took the picture on Dec. 31, 2016, just as the comet was swinging around the sun en route to Earth. Since then 45P's icy nucleus has been heated by solar radiation, causing it to spew brightening jets of gas into the comet's green atmosphere. Why green? Because the comet's vaporizing nucleus emits diatomic carbon, C2, a gas which glows green in the near-vacuum of space.
According to the Minor Planet Center, this is the 8th closest pass of any comet in the modern era (since ~1950, when modern technology started being used to study comets). It will only be 31 times farther from Earth than the Moon. Interestingly, 45P made an even closer approach on its previous orbit (23 lunar distances), so it is also on the list as the 5th closest.
Proximity makes the comet bright despite its small size. Forecasters say 45P could be on the verge of naked eye visibility (6th magnitude) when it emerges into the pre-dawn sky later this week. The best time to look is during the dark hours before sunrise between Feb 9th and 12th. The comet will be racing through the constellation Hercules high in the eastern sky. Sky maps: Feb. 9, 10, 11, 12.
Got a great picture? First, submit it to Spaceweather.com. Next, send it to the Planetary Science Institute, which is collecting amateur images to help professional researchers study Comet 45P. More resources: 3D Orbit, Ephemeris.
FAR-OUT VALENTINE'S GIFT: Did you know that cosmic radiation in Earth's atmosphere is increasing? It's true. These and other findings of the Earth to Sky Calculus ballooning program are funded not by government grants or corporate donations. Instead, the students rely on crowdfunding. Or rather, bear-funding:
To raise funds for their ongoing research, on Jan. 31st the students flew a payload-full of these ursine astronauts to the edge of space. You can have one for $79.95. A space rose is included, too, pressed for safekeeping. Each bear+rose gift package comes with a Valentine's card showing the bears in flight and telling the story of their trip to the stratosphere.
More out of this world gifts may be found in the Earth to Sky store.
Realtime Space Weather Photo Gallery
GREEN ACRES: During the weekend, a high speed stream of solar wind buffeted Earth's magnetic field, sparking bright auroras around the Arctic Circle. Markus Varik photographed the display from Trosmø, Norway:
"The horses were paying no attention to the auroras," says Varik. Apparently, they've seen it all before. Living outdoors, Norwegian horses probably witness more geomagnetic storms than any human observer. "They held very still for my picture, though."
A new outburst of green is expected on Jan. 7th and 8th when another stream of solar wind reaches Earth. Arctic observers (of all kinds) are encouraged to look up on Tuesday and Wednesday nights. Free: Aurora alerts.
Realtime Airglow Photo Gallery