Posts Tagged ‘ison’

See Ya, ISON.

Wednesday, December 4th, 2013

Comet ISON’s Full Perihelion Pass, courtesy of NASA.

After several days of continued observations, scientists continue to work to determine and to understand the fate of Comet ISON: There’s no doubt that the comet shrank in size considerably as it rounded the sun and there’s no doubt that something made it out on the other side to shoot back into space. The question remains as to whether the bright spot seen moving away from the sun was simply debris, or whether a small nucleus of the original ball of ice was still there. Regardless, it is likely that it is now only dust.

Comet ISON, which began its journey from the Oort Cloud some 3 million years ago, made its closest approach to the sun on Nov. 28, 2013. The comet was visible in instruments on NASA’s Solar Terrestrial Relations Observatory, or STEREO, and the joint European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, via images called coronagraphs. Coronagraphs block out the sun and a considerable distance around it, in order to better observe the dim structures in the sun’s atmosphere, the corona. As such, there was a period of several hours when the comet was obscured in these images, blocked from view along with the sun. During this period of time, NASA’s Solar Dynamics Observatory could not see the comet, leading many scientists to surmise that the comet had disintegrated completely. However, something did reappear in SOHO and STEREO coronagraphs some time later — though it was significantly less bright.

Whether that spot of light was merely a cloud of dust that once was a comet, or if it still had a nucleus — a small ball of its original, icy material — intact, is still unclear. It seems likely that as of Dec. 1, there was no nucleus left. By monitoring its changes in brightness over time, scientists can estimate whether there’s a nucleus or not, but our best chance at knowing for sure will be if the Hubble Space Telescope makes observations later in December 2013.

Regardless of its fate, Comet ISON did not disappoint researchers. Over the last year, observatories around the world and in space gathered one of the largest sets of comet observations of all time, which should provide fodder for study for years to come. The number of space-based, ground-based, and amateur observations were unprecedented, with twelve NASA space-based assets observing over the past year.


Comet ISON Thanksgiving

Wednesday, November 27th, 2013

What a treat: we may be able to see the Comet ISON during the Thanksgiving Day holiday. Look for it near the horizon, but don’t look directly into the Sun (duh).

The image above, courtesy of ESA/NASA/SOHO, shows Comet ISON streaming toward the Sun.

In the early hours of Nov. 27, 2013, Comet ISON entered the field of view of the European Space Agency/NASA Solar and Heliospheric Observatory. In this picture, called a coronagraph, the bright light of the sun itself is blocked so the structures around it are visible. The comet is seen in the lower right; a giant cloud of solar material, called a coronal mass ejection or CME, is seen billowing out under the sun.
Comet ISON, which began its trip from the Oort cloud region of our solar system, will reach its closest approach to the sun on Thanksgiving Day, skimming just 730,000 miles above the sun’s surface.
NASA is tracking Comet ISON’s journey and hosting events to discuss what the public worldwide may see as the comet traverses the sun.

Here’s the best video yet…

Check out NASA’s Comet ISON Toolkit for more.

Think astronomers are excited? That’s an understatement. Look at the observation schedule.


Big Bang Monday: Comet ISON

Monday, September 23rd, 2013

CBS Baltimore reports on the Comet ISON, which could prove to be quite a spectacle. The northern hemisphere, for example, will get to see the comet around 11 December 2013

The comet was discovered by ISON (Пулковская кооперация оптических наблюдателей), hence the naming. NASA Science put together this story, explaining it comprehensively…

So it all depends on whether the Sun obliterates it on the go-around.

Remember to check the Hubble ISONblog for updates.