ISON, ISON, ISON!!! Whether or not you’re space geek there is no chance that you didn’t heard this word in last few days, or months actually. All over NASA twitter and space.com’s site you’ll find ISON taking up the biggest proportion. So why is this buzz and most of all what is this buzz all about? Lets see:
Comet ISON Slingshot Around Sun
Astronomers all over the world are training their eyes and telescopes on Comet ISON as it passed its closest distance to the sun on Thursday (Nov. 28), with several unblinking space telescopes offering live views of the comet’s solar encounter.
Comet ISON’s closest approach to the sun, called perihelion, occurred on Thursday at 1:44 p.m. EST (1844 GMT), just in time for the Thanksgiving Day in the United States.
While some predictions suggest that the comet may be visible in daylight, we’d rather say you don’t risk your vision by staring at the sun. It might be possible to block the sun from view with a well-placed chimney or lamp post, but there is a better way, and it’s 100-percent safe: watch live views from space. [Comet ISON’s Sun Encounter: Complete Coverage]
There are several satellites in orbit around the sun which are trained on the sun all the time. One the oldest and still one of the best is SOHO, the Solar and Heliospheric Observatory.
You can see the latest video of Comet ISON from SOHO here.
The sun-watching SOHO spacecraft is a joint mission by NASA and the European Space Agency. It launched in 1995 and carries an array of cameras pointed at the sun. You can see live views from the SOHO spacecraft here: http://sohowww.nascom.nasa.gov/home.html
For purposes of seeing Comet ISON, the most interesting SOHO instrument is the Large Angle and Spectrometric Coronagraph #3, or LASCO C3 for short. This shows a field of view about 32 degrees wide. The sun itself is blocked by a disk at the end of a stalk, its diameter marked by a small white circle.
Because SOHO is in space, there is no atmosphere to scatter the sun’s light, so viewers can see the stars surrounding the sun, just as if we were watching a totalsolar eclipse. Actually, the view is much better than at a total eclipse, with stars down to about 7th magnitude visible — slightly better than what the human eye can see.
Very early in SOHO’s history, astronomers realized that they could observe comets passing very close to the sun, called “sungrazers.” To date, more than 2,400 comets have been discovered by careful skywatchers scanning SOHO’s LASCO C3 images. The images from LASCO are refreshed regularly and can be seen here.
Whenever you check this page, you will see the most recent image from space, usually not more than an hour or two old. Go there right now, and you will see the sun’s current coronal activity and, in the background, the stars on the far side of the sun.
ISON entered LASCO C3’s field of view at right side on uesday 26 November
Here are some tweets about ISON activity by @NASA: