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Comet Hartley 2 is looming larger in a space probe's field of view, and in the cameras of earthbound stargazers as well. But there are even better views to come, on Earth and in the heavens. Soon you can even see it for yourself.
The comet's close approach ranks as one of the stargazing highlights of the year, as well as a highlight for NASA's EPOXI mission. The probe's acronym actually super-glues two abbreviations together: EPOCh (Extrasolar Planet Obervation and Characterization) plus DIXI (Deep Impact eXtended Investigation). Comet 103P/Hartley 2 is the star of the DIXI part of the show. On Nov. 4, the recommissioned Deep Impact spacecraft will come within 450 miles (700 kilometers)of the half-mile-wide (kilometer-wide) comet.
NASA / JPL / UM
Red lines point to Comet Hartley 2 in the EPOXI mission's first picture of its target.
EPOXI's first picture of the gassy, dirty snowball came in last week, and another one was posted just today. You can follow the flow of mission data day by day via @cometexplorer's Twitter updates. But right now, Hartley 2 looks like little more than a fuzzy smudge amid the background stars.
Earthly observers are getting nicer pictures and posting them to EPOXI's Facebook page. The color pictures show the comet surrounded by an eerie greenish glow. British astrophotographer Nick Howes assembled his black-and-white images into a video that tracks Hartley 2 through the night sky:
Just as EPOXI is coming closer to Hartley 2, Hartley 2 is coming closer to Earth with every passing day. Sky & Telescope's Greg Bryant says the comet should reach magnitude 5 or 6 in the constellation Cassiopeia by early October. Usually that would be bright enough for naked-eye observing under optimal conditions. "But it's important to note that ... its light is no longer concentrated into a small dot but instead is more spread out. So even if you can sight a 6th-magnitude star with the unaided eye, Hartley 2 will be tougher," Bryant writes.
Oct. 7 should be about the peak time for comet-watching, in part because there won't be any competing glare from the moon. In the Northern Hemisphere, binoculars and small telescopes should bring Hartley 2 into view — if you know where to look. Sky & Telescope's diagram pinpoints the comet's location as it moves across the sky.
You can also feast your eyes on the cometary imagery popping up on Facebook and the University of Maryland's Amateur Observers' Gallery, as well as on Gary W. Kronk's Cometography website and at the Lowell Observatory.
Photo by Gary W. Kronk
Comet Hartley 2 shines in a picture taken by Gary Kronk from his observatory in Illinois on Sept. 12.
The Planetary Society's Emily Lakdawalla notes that EPOXI's camera doesn't have the resolving power that Earth-based cameras do, and that's one reason why the telescopic images are better now. (Another reason is that Earth is currently closer to Hartley 2 than EPOXI is, due to the spacecraft's looping trajectory.)
All that will change as EPOXI closes in for its encounter and sends back not just dozens of images, but tens of thousands of images. "Space cameras eventually take better pictures of targets because they get much closer to them," Lakdawalla says.
I can hardly wait.
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Leave a Comment:
I remember when Halie's comet came around . I set up my little telescope and went in the house and waited for dark . I went out to try to find it and it was the WHOLE sky .. Way cool ..
There was a time, early 17th century, where the appearance of a comet lead to major science-religion discourse. Not any more - unless the dirty snowball takes aim at Washington, Moscow or Mecca, then the newsvine page would fill to overflowing.
My wife still doesn't like comets. She thinks they are harboring bad luck.
Who know the myth about this?
Probably Comets have a bad name as they often hearlded somthing negative in acient history. There is also debate that some prehistoric civilization or civilizations were devastated or wiped out by one, but the hard evidence is spotty.
There was a comet event in China in the 15 century that killed about 10,000 people.
That would have been a meteorite and not a comet. Comets never leave deep space. If they entered our atmosphere, they would melt as they are mostly made of ice and dust.
Don't forget about the Tunguska event in 1908.
http://en.wikipedia.org/wiki/Tunguska_event
Maybe someone can help me. I've been waiting for this to come around... but it looks as though only people in the Northern Hemi will see it? Bummed if this is the fact.
Although it is pretty far north up by Cassiopeia, it will start to head south during Oct. By 4 Nov it will be over by Canis Minor...
But hey, you far southerners had comet McNaught that was uber spectacular in the southern hemisphere.
What DIRECTION should I look in??? I can't figure out the "constellations".
You dont see a bear up there ? ....Awww come on ...
NE. You need to look for a group of stars that looks sort of like a dot-to-dot "W". It will be somewhat to the right of the Big Dipper. At least you can find that, right?
up!!!
The comet is in the NE sky up by Pegasus and Andromeda and heading towards Cassiopeia. It is currently about mag 11, so pretty dim... During Oct, it will be passing Cassiopeia down towards Perseus. It will also be getting brighter as it has its closest approach to Earth on 20 Oct, perihelion on 28 Oct and the EPOXI mission flyby on 4 Nov. Visit the websites linked in the blog to learn more!