SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
COMET ENCOUNTER: The big moment is just hours away. NASA's Deep Impact (EPOXI) probe is plunging into the heart of Comet Hartley 2 for a 435 mile close encounter on Nov. 4th around 10 am EDT. The small but active comet is full of surprises, with spinning jets, geysers of cyanide gas, and a strangely pickle-shaped core. Mission scientists expect to reveal first images from the flyby during a press conference on Thursday afternoon at 4 pm EDT. Tune into NASA TV to follow events live.
FARSIDE FLARES: An active region just over the sun's eastern horizon is crackling with solar flares and hurling material high above the stellar surface. This extreme ultraviolet movie from NASA's Solar Dynamics Observatory shows the strongest blast so far, a C4-class event at 1220 UT on Nov. 3rd:
movie formats: 3.8 MB mpeg, 0.9 MB iPad, 0.3 MB iPhoneAlthough the blast site is hidden behind the limb, the eruption nevertheless yielded enough x-radiation to produce a wave of ionization in Earth's upper atmosphere. Researcher Rob Stammes recorded a sudden ionospheric disturbance (SID) when the wave passed over his lab in Laukvik, Norway. Learn more about SIDs here.
The source of this activity is an old friend--a sunspot and magnetic filament jointly known as "active region 1112." The ensemble put on a good show in mid-October when it first crossed the face of the sun. For the past two weeks, however, it has been transiting the far side, out of sight. Today's eruption may be read as "hello, I'm back." The sun's rotation is bringing the region around for a second pass; readers with solar telescopes are encouraged to monitor the eastern limb for its emergence in the days ahead.
FIRST AURORAS OF NOVEMBER: October 2010 produced some of the finest auroras in years around the Arctic Circle--a sign that the sun is waking up for a new solar cycle. Will November 2010 be even better? The month got off to a good start last night in Kvaløya, Norway:
"The auroras were fantastic," says photographer Fredrik Broms. "Our day began quietly, rather warm with some newly-fallen snow, and then we got a solar storm. Weather changes quickly!"
The display was sparked by a fluctuation in the solar wind. Magnetic fields inside the solar wind tipped south and partially canceled the magnetic field of our own planet. This opened a hole in Earth's magnetosphere. Solar wind poured in and ignited the auroras.
Bonus: "I could also see Comet Hartley 2 through ordinary 8x42 binoculars," says Broms. "Here it is in a wide-angle shot of the auroras." NASA's Deep Impact/EPOXI probe will get a closer look on Nov. 4th when it flies only 435 miles from the comet's surprising core. Stay tuned.
Comments
Post a Comment