Space Weather

[thelufias]

Astronomers’ 1st close-up look near a supermassive black hole

[Jherrith]

VOYAGER 2 ENTERS INTERSTELLAR SPACE: Voyager 2 has exited the sun's magnetic bubble and entered interstellar space. Mission scientists announced the breakthrough earlier today at the American Geophysical Union meeting in Washington DC. Its twin, Voyager 1, crossed the same boundary in 2012, but Voyager 2's crossing is arguably more significant because it carries a working instrument that can sense interstellar plasmas, providing the first in situ sampling of matter between the stars.



The most compelling evidence of Voyager 2's exit from the heliosphere came from its onboard Plasma Science Experiment (PLS), an instrument that stopped working on Voyager 1 in 1980. Until recently, Voyager 2 was surrounded mainly by the solar wind--a type of plasma flowing outward from the sun. On Nov. 5th, Voyager 2's plasma instrument observed a sharp decline in the solar wind, and since that date, it has observed no solar wind flow--a clear sign that the probe has left the heliosphere.

Replacing the solar wind is a blizzard of galactic cosmic rays. The sun's magnetic field substantially protects the solar system from cosmic rays, fending off the high energy debris of supernova explosions in the Milky Way and elsewhere. Now that Voyager 2 has exited that protective shell, it is baldly exposed to cosmic rays, and its cosmic ray subsystem is registering a surge.



Launched in 1977, Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth.

The Voyager probes are powered using heat from the decay of radioactive material, contained in a radioisotope thermal generator (RTG). The power output of the RTGs diminishes by about four watts per year, which means that various parts of the Voyagers, including the cameras on both spacecraft, have been turned off over time to manage power. Thanks to these precautions, the Voyagers could continue to send back at least some data for years to come.
"There is still a lot to learn about the region of interstellar space immediately beyond the heliosphere," said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California. Stay tuned for updates from the stars.

[thelufias]

Read that earlier on and thought how cool it was....Figured you'd get it in here so went back to VR LOLOLOL

[sidherose]

Wow...dR and I were just talking the other day on the phone about Voyager II and if it had reached interstellar space yet. And here it is! Cool, indeed

[Jherrith]

THE GEMINID METEOR SHOWER IS UNDERWAY:

Earth is entering a stream of debris from rock comet 3200 Phaethon, source of the annual Geminid meteor shower. Members of the International Meteor Organization say they're now seeing more than a dozen meteors per hour over dark-sky sites. These rates could increase 5- to 10-fold by the time the shower peaks on Dec. 13-14. A good time to look is during the dark hours before dawn when the constellation Gemini is high in the sky.

[Jherrith]

Wow...dR and I were just talking the other day on the phone about Voyager II and if it had reached interstellar space yet. And here it is! Cool, indeed

Serendipity is wonderful is it not ...

[Jherrith]

A GEMINID BUZZES COMET WIRTANEN: The radiant of the Geminid meteor shower is not very far from approaching Comet 46P/Wirtanen. Their respective constellations, Gemini and Taurus, are next door neighbors. That means comet photographers can expect to catch some Geminids in their exposures. Indeed, that's exactly what happened to Joe Lawton of Gerald, Missouri, on Dec. 9th. "As I was photographing 46P/Wirtanen, a Geminid meteor blazed across the sky and disintegrated next to the comet!"



"I combined a series of still images to create this video," he explains. "You can see smokey debris from the Geminid meteoroid twisting in the winds of the upper atmosphere and ultimately dissipating."

How often is this happening? Just last night Harlan Thomas of Powderface Trail, Alberta, and Dr. Paolo Candy of the Cimini Astronomical Observatory in Italy also caught Geminids streaking past the comet.

Experienced observers report that Comet 46P/Wirtanen is now about as bright as a 5th magnitude star. Stars of that magnitude are visible to the unaided eye, but unlike a star, which concentrates its luminosity in a point, the comet's brightness is spread out over an area twice as wide as a full Moon. This makes it difficult to see naked-eye, but an easy target for digital cameras on tripods. Photographers submitting to our Comet Photo Gallery are having success with 10-to-60 second exposures at ISOs between 1600 and 6400.

Readers, would you like to photograph the comet and the meteor shower at the same time? It can be done during the hours before midnight when Gemini and Taurus are hanging together in the southeastern sky. These sky maps are tailored to that purpose:

[sidherose]

Serendipity is wonderful is it not ...

I guess - as long as it's not being weird

[Jherrith]

Aw,  ... that takes all the fun out of it

[sidherose]

Well, we were born on the same day. We have several weird synchronicities. But no, it doesn't take the fun out of it. Just quite a few are of the odd variety.