Deep Impact/EPOXI

[EarthlingX]

Re: Deep Impact. Results & Extended mission.

SDC : Comet-Hunting Spacecraft Nears Icy Target

By SPACE.com Staff

posted: 19 October 2010
04:59 pm ET



A comet-chasing spacecraft is closing in on its icy quarry, gearing up for a close flyby on Nov. 4.

On that date, NASA's Deep Impact spacecraft will pass a mere 435 miles (702 kilometers) from Comet Hartley 2. The probe has already trained its instruments on the ice ball, preparing for what mission planners describe as the best-ever extended look at a comet. [Photo of Hartley 2.]

"There are billions of comets in the solar system, but this will be only the fifth time a spacecraft has flown close enough to one to snap pictures of its nucleus," mission science team member Lori Feaga, of the University of Maryland, said in a statement. "This one should put on quite a show."

...

 

[EarthlingX]

Re: Deep Impact. Results & Extended mission.

http://www.jpl.nasa.gov : The Comet Cometh: Hartley 2 Visible in Night Sky

October 19, 2010


This image of comet Hartley 2 was captured by amateur astronomer Byron Bergert on Oct. 6 in Gainesville, Florida using a 106 mm Takahashi astrograph. Image credit: Byron Berger

Backyard stargazers with a telescope or binoculars and a clear night's sky can now inspect the comet that in a little over two weeks will become only the fifth in history to be imaged close up. Comet Hartley 2 will come within 17.7 million kilometers (11 million miles) of Earth this Wed., Oct. 20 at noon PDT (3 p.m. EDT). NASA's EPOXI mission will come within 700 kilometers (435 miles) of Hartley 2 on Nov. 4.

"On October 20, the comet will be the closest it has ever been since it was discovered in 1986 by Australian astronomer Malcolm Hartley," said Don Yeomans, head of NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif. and a member of the EPOXI science team. "It's unusual for a comet to approach this close. It is nice of Mother Nature to give us a preview before we see Hartley 2 in all its cometary glory with some great close-up images less than two weeks later."

Comet Hartley 2, also known as 103P/Hartley 2, is a relatively small, but very active periodic comet that orbits the sun once every 6.5 years. From dark, pristine skies in the Northern Hemisphere, the comet should be visible with binoculars as a fuzzy object in the constellation Auriga, passing south of the bright star Capella. Viewing of Hartley 2 from high ambient light locations including urban areas may be more difficult.

In the early morning hours of Oct. 20, the optimal dark sky window for mid-latitude northern observers is under two hours in length. This dark interval will occur between the time when the nearly-full moon sets at about 4:50 a.m. (local time) and when the morning twilight begins at about 6:35 a.m.

By October 22, the comet will have passed through the constellation Auriga. It will continue its journey across the night sky in the direction of the constellation Gemini.

...

The animation shows Comet Hartley 2 moving through the night sky on Oct. 1, 2010 as captured by amateur astronomer Patrick Wiggins of Utah. The animated gif consists of a series of 13 ten-second exposures of the comet each spaced five minutes apart between 0901 and 1004 UTC. Wiggins, who is also a NASA/JPL Solar System Ambassador, used a 35cm Celestron C-14 operating at f/5.5. Image Credit: Patrick Wiggins, NASA/JPL Solar System Ambassador

...

Images and videos of comet Hartley 2 from both amateur observers and major observatories are online at: http://aop.astro.umd.edu/gallery/hartley.shtml

..


aop.astro.umd.edu : Image taken by Konstantinos Stavropoulos
...

...


Charts to find it in the sky :


www.skyandtelescope.com : Comet Hartley 2 At Its Best

October 18, 2010
by Greg Bryant and the editors of Sky & Telescope

...

Charts are now available for the entire time when Comet Hartley 2 is expected to be 10th magnitude or brighter. Click on one of the links below for:

Hartley 2's path before Oct. 18
Hartley 2's path from Oct. 18 to Nov. 3
Hartley 2's path from Oct. 30 to Nov. 15
Hartley 2's path from Nov. 15 to Dec. 31

...

 

[EarthlingX]

Re: Deep Impact. Results & Extended mission.

SDC : Comet Hartley 2 Makes Closest Pass by Earth in 24 Years

By SPACE.com Staff

posted: 20 October 2010
06:03 pm ET



A comet passed silently by Earth today (Oct. 20), coming closer to our planet than it has since 1986, when astronomers first discovered the icy wanderer.

Comet Hartley 2 passed within 11 million miles (17.7 million km) of Earth at about 3 p.m. EDT (1900 GMT) today — much closer than the Earth is to the sun (about 93 million miles, or 150 million km). [Photo of Comet Hartley 2.]

The close Earth pass comes just two weeks ahead of another flyby for the comet. NASA's Deep Impact spacecraft is chasing Hartley 2, gearing up for a Nov. 4 comet flyby, during which the probe will come within 435 miles (700 km) of the cosmic ball ice and rock.

"It's unusual for a comet to approach this close," said Don Yeomans, head of NASA's Near-Earth Object Office at the Jet Propulsion Laboratory in Pasadena, Calif., and a member of Deep Impact's mission science team, in a statement. "It is nice of Mother Nature to give us a preview before we see Hartley 2 in all its cometary glory with some great close-up images less than two weeks later."

Backyard stargazers with binoculars or telescopes — and dark, clear skies — should be able to see Comet Hartley 2 this week.

...

 

[MeteorWayne]

PASADENA, Calif. -- NASA is hosting a media teleconference at 11 a.m. PDT on Tuesday Oct. 26, to preview the EPOXI mission's upcoming flyby and study of the comet Hartley 2. The Nov. 4 encounter will provide the best, extended view of a comet in history.

The EPOXI mission, which uses the already "in-flight" Deep Impact spacecraft, will pass within approximately 435 miles of the half-mile-wide comet. The spacecraft will use two telescopes with digital color cameras and an infrared spectrometer to examine the dusty, icy body in detail during the flyby.

To participate in the teleconference, reporters must contact the media relations office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., at 818-354-5011 to obtain the call-in number and passcode.

Teleconference participants are:

-- Michael A'Hearn, principal investigator, University of Maryland in College Park, Md.
-- Tim Larson, EPOXI project manager, Jet Propulsion Laboratory
-- Amy Walsh, EPOXI systems engineering lead, Ball Aerospace & Technologies in Boulder, Colo.
-- Malcolm Hartley, astronomer and discoverer of Hartley 2

Audio of the teleconference will be streamed live at:


http://www.nasa.gov/newsaudio

The term EPOXI is a combination of the names for the two extended mission components: the Extrasolar Planet Observations and Characterization (EPOCh), and the Hartley 2 flyby, called the Deep Impact eXtended Investigation (DIXI). For more information about EPOXI, visit:

http://www.nasa.gov/epoxi

http://epoxi.umd.edu

 

[EarthlingX]

http://www.nasa.gov : Five Things About NASA's EPOXI Mission

10.25.10


This artist's concept shows us the first time Deep Impact encountered a comet - Tempel 1 in July 2005. Deep Impact, now in an extended mission called EPOXI, will fly by its next comet, Hartley 2, on Nov. 4, 2010. Image Credit: NASA/JPL-Caltech/UMD

Here are five quick facts about the EPOXI mission, scheduled to fly by comet Hartley 2 on Nov. 4, 2010.

1. High Fives - This is the fifth time humans will see a comet close-up, and the Deep Impact spacecraft flew by Earth for its fifth time on Sunday, June 27, 2010.

2. Eco-friendly Spacecraft: Recycle, Reuse, Record - The EPOXI mission is recycling the Deep Impact spacecraft, whose probe intentionally collided with comet Tempel 1 on July 4, 2005, revealing, for the first time, the inner material of a comet. The spacecraft is now approaching a second comet rendezvous, a close encounter with Hartley 2 on Nov. 4. The spacecraft is reusing the same trio of instruments used during Deep Impact: two telescopes with digital imagers to record the encounter, and an infrared spectrometer.

3. Small, Mighty and Square-Dancing in Space - Although comet Hartley 2 is smaller than Tempel 1, the previous comet visited by Deep Impact, it is much more active. In fact, amateur skywatchers may be able to see Hartley 2 in a dark sky with binoculars or a small telescope. Engineers specifically designed the mighty Deep Impact spacecraft to point a camera at Tempel 1 while its antenna was directed at Earth. This flyby of comet Hartley 2 does not provide the same luxury. It cannot both photograph the comet and talk with mission controllers on Earth. Engineers have instead programmed Deep Impact to dance the do-si-do. The spacecraft will spend the week leading up to closest approach swinging back and forth between imaging the comet and beaming images back to Earth.

4. Storytelling Comets - Comets are an important aspect of studying how the solar system formed and Earth evolved. Comets are leftover building blocks of solar system formation, and are believed to have seeded an early Earth with water and organic compounds. The more we know about these celestial bodies, the more we can learn about Earth and the solar system.

5. What's in a Name? - EPOXI is a hybrid acronym binding two science investigations: the Extrasolar Planet Observation and Characterization (EPOCh) and Deep Impact eXtended Investigation (DIXI). The spacecraft keeps its original name of Deep Impact, while the mission is called EPOXI.


Priscilla Vega 818-354-1357
Jet Propulsion Laboratory, Pasadena, Calif.
Priscilla.r.vega@jpl.nasa.gov

 

[MeteorWayne]

http://www.nasa.gov/mission_pages/epoxi ... 01021.html

Recent observations of comet Hartley 2 have scientists scratching their heads, while they anticipate a flyby of the small, icy world on Nov. 4.

A phenomenon was recorded by imagers aboard NASA's Deep Impact spacecraft from Sept. 9 to 17 during pre-planned scientific observations of the comet. These observations, when coupled with expected images during the closest encounter with Hartley 2 on Nov. 4, will become the most detailed look yet at a comet's activity during its pass through the inner-solar system.

"On Earth, cyanide is known as a deadly gas. In space it's known as one of the most easily observed ingredients that is always present in a comet," said Mike A'Hearn of the University of Maryland, College Park. A'Hearn is principal of EPOXI, an extended mission that utilizes the already "in flight" Deep Impact spacecraft. "Our observations indicate that cyanide released by the comet increased by a factor of five over an eight-day period in September without any increase in dust emissions," A'Hearn said. "We have never seen this kind of activity in a comet before, and it could affect the quality of observations made by astronomers on the ground."

The new phenomenon is very unlike typical cometary outbursts, which have sudden onsets and are usually accompanied by considerable dust. It also seems unrelated to the cyanide jets that are sometimes seen in comets. The EPOXI science team believes that astronomers and interested observers viewing the comet from Earth should be aware of this type of activity when planning observations and interpreting their data.

 

[3488]

I wonder Wayne, if 103P/Hartley 2 is a relative newcomer to the Jupiter Family?????? I.e once was from the outer KB or even a fairly 'recent' Oort Cloud import?

The peculiar activity & the enhanced cyanide signature is most interesting.

Wasn't C/1996 B2 Hyakutake weird in that respect too?

103P/Hartley2 as seen from Deep Impact on: Saturday 23rd October 2010. From approx 13 million KM.

NASA / JPL-Caltech / University of Maryland.

Andrew Brown.

 

[MeteorWayne]

It has been suggested that 103P/ Hartley 2 is an Oort cloud comet. (M.F. A'Hearn et al, Icarus 118, 1995 ) This is based on the high CO2 to water ratio and water ortho-to-para ratio, implying creation at a temp fo 35 K. These were similar to Hale-Bopp.

Although it came form there it has been in the "inner" solar system for quite a while, but only since 1971? was the perihelion reduced from 1.6 AU to the current ~ 1 AU, after one of many close encounters with Jove.

For explanation of ortho-para see:
http://en.wikipedia.org/wiki/Spin_isomers_of_hydrogen

(Bring an ice pack for your brain)

 

[EarthlingX]

[youtube]http://www.youtube.com/watch?v=7tm5p96ag7Q[/youtube]

JPLnews | October 26, 2010

Cool leftovers! Comets are the leftover building blocks of solar system formation. NASA's Epoxi mission will fly by a comet to learn how our solar system may have gotten its start..

 

[EarthlingX]

Multimedia and telecon audio :
http://www.nasa.gov : Epoxi Media Telecon

10.26.10

...

Press release, with video :

http://www.nasa.gov : Countdown to Comet Flyby Down to Nine Days

10.26.10

PASADENA, Calif. – NASA's EPOXI mission continues to close in on its target, comet Hartley 2, at a rate of 12.5 kilometers (7.8 miles) per second. On Nov. 4 at about 10:01 a.m. EDT (7:01 a.m. PDT) the spacecraft will make its closest approach to the comet at a distance of about 700 kilometers (434 miles). It will be the fifth time that a comet has been imaged close-up and the first time in history that two comets have been imaged with the same instruments and same spatial resolution.

"Hartley 2 has already put on a great show with more than a few surprises for the mission's science team," said EPOXI principal investigator Mike A'Hearn from the University of Maryland, College Park. "We expect more of the unexpected during encounter."

Science observations of comet Hartley 2 began on Sept. 5. The imaging campaign is more than a tantalizing tease of things to come. It is providing EPOXI's science team the best extended view of a comet in history during its pass through the inner solar system. The observations will continue through the encounter phase of the mission.

The hours surrounding comet encounter will be especially challenging for the mission team as they are commanding a recycled spacecraft that was not designed for this comet flyby. The spacecraft was designed and employed successfully for NASA's Deep Impact encounter of comet Tempel 1 back on July 4, 2005. By recycling Deep Impact's already built, tested and in-flight spacecraft, the EPOXI mission provided savings on the order of 90% that of a hypothetical mission with similar goals, starting from the ground up.

"If we were starting from scratch we'd probably move some of the spacecraft's components to different locations," said Tim Larson, project manager for the EPOXI mission from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "But we’ve developed a creative way to work with what we have. This spacecraft, and mission team, have logged 3.2 billion miles over the past five years, and we are confident that we have a successful plan in place to give Hartley 2 a thorough look-see."

The mission's encounter phase begins the evening of Nov. 3, when the spacecraft is about 18 hours from the time of closest approach to the comet's nucleus. At that time the spacecraft will stop transmitting through its large high-gain antenna and reorient itself so its two visible-light and one infrared imager maintain lock on the comet for the next 24 hours-plus.

"When the encounter phase begins all images the spacecraft takes will be stored aboard its two computers," said Larson. "Soon after we fly past the comet at about 7 a.m. local time, we will be able to re-orient the spacecraft so that we maintain imaging lock on the comet nucleus while pointing our big high gain antenna at Earth."

At that point, the spacecraft will begin beaming down its cache of cometary close-ups while continuing to take new images. It is expected to take several hours for all the images held aboard spacecraft memory to be downliked.

"We will be waiting," said A'Hearn. "The images at closest approach won't get to Earth until many hours after the actual encounter due to the way we use memory on the spacecraft. We will get some early hints at how this nucleus differs from that of comet Tempel 1 based on five images that will get to Earth only about one hour after closest approach."

EPOXI is an extended mission that utilizes the already "in-flight" Deep Impact spacecraft to explore distinct celestial targets of opportunity. The name EPOXI itself is a combination of the names for the two extended mission components: the extrasolar planet observations, called Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI). The spacecraft will continue to be referred to as "Deep Impact."

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the EPOXI mission for NASA's Science Mission Directorate, Washington. The University of Maryland, College Park, is home to the mission's principal investigator, Michael A'Hearn. Drake Deming of NASA's Goddard Space Flight Center, Greenbelt, Md., is the science lead for the mission's extrasolar planet observations. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

For information about EPOXI, visit http://www.nasa.gov/epoxi or http://epoxi.umd.edu/.

planetary.org : A couple of tidbits from today's Deep Impact preview briefing

Oct. 26, 2010 | 13:01 PDT | 20:01 UTC

By Emily Lakdawalla

Today was the press briefing that previewed the upcoming Deep Impact flyby of Hartley 2. This briefing wasn't particularly well attended by press, because it's the sort of briefing where almost all of the information they would be relaying was already released -- these preview briefings are mostly for press who haven't been paying much attention. So there weren't any real surprises, as expected; most of what was said has already been mentioned in such places as the Deep Impact Hartley 2 flyby timeline I posted last week. (I should mention that I have recently corrected some errors in the timeline, most importantly my incorrect time conversions to UTC; I hadn't realized that Daylight Saving Time was still in effect here in California through November 7. To make things more confusing, this flyby is happening during the week when Europe will have shifted back from Summer Time, but the USA is still under Daylight Saving Time. Everything in my timeline should be fixed now.)

Still, there were a few interesting tidbits worth reporting. Tim Larson, EPOXI mission project manager, said that the 700-kilometer flyby distance was chosen both for spacecraft safety (to keep the spacecraft far enough away from the coma and its dust) and to allow it to track the comet nucleus comfortably within the spacecraft's maximum turn rate. For comparison, Deep Impact flew within 500 kilometers of Tempel 1.

...
[youtube]http://www.youtube.com/watch?v=yYwHNPfFJwY[/youtube]

planetsocblog | October 26, 2010

Credit: NASA / JPL / UMD
Images taken as Deep Impact approached Hartley 2, from October 15 to 24, 2010.

...

 

[MeteorWayne]

Starting today:

Approach Imaging
For 6 days, until 1 day before the flyby, Deep Impact acquires MRI and HRIVIS images every 2 minutes and HRIIR spectral scans every hour. Compared to the previous imaging phase, images are captured 2.5 times more frequently, while spectral scans are taken only half as often. Imaging is conducted for 16 hours, then turns to downlink data in a communications session lasting 8 hours.

http://www.planetary.org/explore/topics ... eline.html

 

[MeteorWayne]

Also, check out dmuller's realtime simulation:

http://dmuller.net/spaceflight/realtime ... &mode=scet

 

[EarthlingX]

http://www.physorg.com : Space radar provides taste of Comet Hartley 2

October 29, 2010

By DC Agle


Twelve radar images of the nucleus of comet Hartley 2 were obtained by the Arecibo Observatory's planetary radar from Oct 25 to 27, 2010. Image credit: NAIC-Arecibo/Harmon-Nolan

Exactly one week before the world gets a new look at comet Hartley 2 via NASA's EPOXI mission, observations of the comet by the Arecibo Planetary Radar in Puerto Rico have offered scientists a tantalizing preview.

"It kind of looks like a cross between a bowling pin and a pickle," said EPOXI project manager Tim Larson of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Only it's about 14-thousand-times larger and hurtling through space at 23 miles per second." A new image is online at http://www.naic.edu/~pradar/103P .

Scientists using Arecibo's massive radar dish began observations of Hartley 2 on Oct. 24, just four days after the comet made its closest approach to Earth since its discovery in 1986. (On Oct. 20, the comet came within 17.7 million kilometers, or 11 million miles, of Earth). The observations are scheduled to continue through Friday, Oct. 29.

During the Nov. 4 flyby, the cameras aboard the EPOXI mission spacecraft will get within 700 kilometers (about 435 miles) of the comet.

"Observing comet Hartley 2 from the Earth with radar was like imaging a 6-inch spinning cucumber from 836 miles away," said Jon Giorgini, a scientist at JPL and a member of the Arecibo team that imaged the comet. "Even without all the data in, we can still make some basic assertions about Hartley 2. Its nucleus is highly elongated and about 2.2 kilometers [1.4 mile] long, and it rotates around itself about once every 18 hours. In addition we now know the size, speed and direction of particles being blown off the comet, and we immediately forwarded all this information to the EPOXI team."

...

 

[3488]

WOW WOW WOW :mrgreen:

Thank you so much EarthlingX.

If you look at image #8 in that montage, there is what appears to be a crater or depression on the nucleus.

We will know for sure next Thursday.

Below my own enlarged, contrast enhanced, sharpened effort.

Andrew Brown.

 

[EarthlingX]

Nice job and interesting thought about a crater It could also be something shadowing that region, like ridge, extrusion .. ?
As you said, until Thursday

It spins a lot, it seams.

 

[MeteorWayne]

Now under 6 million km....

 

[3488]

Thanks Wayne,

Getting exciting. Wonder what orientation the nucleus will be in at CA??

Does not matter really, what we will see will be of immense scientific importance.

Like what you said in reply to my suggestion that 103P/Hartley 2 may be a relative newcomer, you seem to agree, that the lower perihelion is very recent.

Quite a diffenrence from 1.6 AU to 1 AU, in the amount of sunlight reaching the comet, nearly 2.5 times the difference. So the previous perihelia was still just outside of Mars's orbit, not that far inside the inner edge of the Asteroid Belt. This will be fascinating.

This is almost like the Asteroid 21 Lutetia encounter with Rosetta in many ways, we get to see an object we know so little about being transformed into a world in it's own right, within hours.

What a time we are living through. There has been talk of an extended, extended mission. After Thursday I will dig & try & find out what options there are. I hope it may be a Near Earth Asteroid although another comet would not go amiss. :mrgreen:

Andrew Brown.

 

[MeteorWayne]

Interesting thought to consider future targets...EPOXI is in an orbit from 0.974 to 1.218 AU, and I image it has little propellant left to substantially change that. Have to look at something in that range over the next year or 3

 

[MeteorWayne]

NASA to Host Live Events for November 4 Comet Encounter WASHINGTON -- NASA will hold a series of media and educational events about the EPOXI mission's close encounter with comet Hartley 2 at approximately 7 a.m. PDT on Thursday, Nov. 4. The spacecraft will provide the most extensive observations of a comet in history.

Live coverage beginning at 6:30 a.m. from mission control at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., will be broadcast on NASA Television's Media Channel and the agency's website. A post-flyby news briefing is planned for 1 p.m. For NASA TV streaming video, scheduling and downlink information, visit:

http://www.nasa.gov/ntv

The timeline for mission coverage is (all times PDT and subject to change):

6:30-8:30 a.m. -- NASA TV commentary begins from mission control and includes coverage of closest approach, an educational segment, and the return of close approach images.
1 p.m. -- News briefing following encounter. Participants may include:
Ed Weiler, associate administrator, Science Mission Directorate at NASA
Headquarters in Washington
Michael A'Hearn, principal investigator, University of Maryland
Jessica Sunshine, EPOXI scientist, University of Maryland
Tim Larson, EPOXI project manager at JPL

Activities will also be carried live on one of JPL's Ustream channels at:

http://www.ustream.tv/user/NASAJPL2

The public can watch a real-time animation of the EPOXI comet flyby using NASA's new "Eyes on the Solar System" Web tool. JPL created this 3-D environment that allows people to explore the solar system directly from their computers. Visit:

http://solarsystem.nasa.gov/eyes

EPOXI is an extended mission that utilizes the already "in-flight" Deep Impact spacecraft to explore distinct celestial targets of opportunity. The term EPOXI is a combination of the names for the two extended mission components: the Extrasolar Planet Observations and Characterization (EPOCh), and the Hartley 2 flyby, called the Deep Impact eXtended Investigation (DIXI). For more information about EPOXI, visit:

http://www.nasa.gov/epoxi

 

[3488]

Thanks Wayne,

The times are really useful PDT = UTC -7 Hours.

I will be watching live & I will do as I did with 21 Lutetia, throw screen dumps up first, then post up some better ones later.

Andrew Brown.

 

[MeteorWayne]

"Two movies derived from images taken by the two cameras aboard NASA's EPOXI mission spacecraft show comet Hartley 2 is, as expected, quite active, and it provides information on the nucleus's rotation. The spacecraft has been imaging Hartley 2 almost daily since Sept. 5, in preparation for its scheduled Nov. 4 flyby of the comet.

"The comet brings us new surprises every day," said Michael A'Hearn, EPOXI principal investigator from the University of Maryland, College Park. "The data we have received to this point have been tremendous. It is forcing us to rethink what we know about cometary science, and we are still days away from encounter."

On Oct. 26, the spacecraft's two cameras, a High-Resolution Imager (HRI), and a Medium-Resolution-Imager (MRI), caught two jets firing off the comet's surface over a 16-hour period. The spacecraft captured these images from a distance of about 8 million kilometers (5 million miles) away. The data lead mission scientists to believe that both jets originate from similar latitudes on the comet's nucleus. "

http://www.nasa.gov/mission_pages/epoxi ... 01101.html

Here's a direct link to the video:

http://www.nasa.gov/multimedia/videogal ... d=25454351

Maybe EX can figure out a way to post in here....very cool!

 

[EarthlingX]

Emily Lakdawalla to the rescue :

http://www.planetary.org : Deep Impact movies of outbursts from Hartley 2

Nov. 1, 2010 | 20:38 PDT | Nov. 2 03:38 UTC

By Emily Lakdawalla

Since comet Hartley 2 -- the target of Deep Impact's November 4 flyby -- is near its perihelion, it's no surprise that it's an active comet with lots of outbursts. Even though I know that, it's really exciting to see jets flaring out from the comet from a spacecraft that's tracking its every move, about to fly within a few hundred kilometers of its nucleus. The Deep Impact team released two videos this evening of this outburst activity on October 26 and 27.

...

[youtube]http://www.youtube.com/watch?v=L7--8tTi7WU[/youtube]
Deep Impact HRI view of Hartley 2 jet, Oct 26 2010
Credit: Donald J. Lindler, Sigma Space Corporation and NASA/JPL-Caltech/UMD

[youtube]http://www.youtube.com/watch?v=lCumO7Y45u8[/youtube]
Deep Impact MRI view of Hartley 2 jet, Oct 26 2010
Credit: NASA/JPL-Caltech/UMD (Tony Farnham)

...

 

[MeteorWayne]

Exactly 2 days to Close Approach 2.1 million km away...

 

[EarthlingX]

http://www.jpl.nasa.gov : NASA Spacecraft on Final Approach Toward Comet

November 02, 2010


EPOXI navigation team members and engineers were in mission control for the final flight-path maneuver before the spacecraft's planned Nov. 4 flyby of comet Hartley 2. Image credit: NASA/JPL-Caltech

The EPOXI mission spacecraft has refined its path toward a Nov. 4 flyby of comet Hartley 2, successfully performing its final maneuver today at 8 a.m. PDT (11 a.m. EDT). The spacecraft burned its engines for 6.8 seconds, changing the spacecraft's velocity by 1.4 meters per second (3 miles per hour).

"I've worked the Stardust flyby of comet Wild 2 and the Deep Impact encounter with comet Tempel 1, and I have never seen a comet flit around the sky like this one," said mission navigator Shyam Bhaskaran of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We needed to make this burn to re-locate the spacecraft for the 700-kilometer [about 435 miles] flyby distance."

Part of the reason Hartley 2 is hard to pin down is because the small comet is very active.

"Hartley 2 is one-seventh the size of comet Tempel 1, but it releases almost the same amount of material into the space environment," said EPOXI Principal Investigator Mike A'Hearn of the University of Maryland. "These jets can act as thrusters and actually make small changes to the comet's orbit around the sun."

On Thursday, Nov. 4, the spacecraft will fly past the comet, with closest approach expected about 7 a.m. PDT [10 a.m. EDT]. This flyby will mark the fifth time in history that a spacecraft has been close enough to image the heart of the comet, more commonly known as the nucleus.

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http://www.jpl.nasa.gov : The Man Behind Comet Hartley 2

November 02, 2010


Malcolm Hartley of the Anglo-Australian Observatory, Siding Spring, New South Whales, Australia. Image credit: Jonathan Pogson

Over the last 40 years, Malcolm Hartley has done just about every possible job for Siding Spring Observatory's UK Schmidt telescope in New South Wales, Australia. The British-born, Scottish-educated Hartley has logged time as the 1.2 meter (3.9 foot) telescope's observer, processor, copier, hypersensitization expert, and quality controller.

On the afternoon of March 16, 1986, Hartley's job was that last one -- quality control. In that role, he was the first to view each 36-by-36 centimeter (14-by-14 inch) photographic glass plate after it had been exposed to the night sky. Checking for imperfections on one of the previous evening's 60-minute illuminations, Hartley came upon something that wasn't supposed to be there.

"Back then, the observations came in as negatives -- stars and other objects in the sky appeared black on a clear background," said Hartley. "I noticed a dark haze around a trail. Trails indicate something that is traveling fast through the sky, but asteroids don't have a haze. So I thought it might be a comet."

Hartley double-checked his sighting a couple of nights later, then submitted his findings to the Minor Planet Center in Cambridge, Mass. A couple of days after that, the center issued a brief circular informing the astronomical world of the discovery of comet Hartley 2.

"I was very happy for a couple of days," said Hartley."Every scientist wants to discover something and it's a fantastic feeling. There was even a mention in the local paper, the Coonabarabran Times."

...

 

[EarthlingX]

SDC : Q&A With Malcolm Hartley, Discoverer of Comet Hartley 2

By Mike Wall
SPACE.com Senior Writer
posted: 03 November 2010
08:24 am ET

On Nov. 4, NASA's Deep Impact spacecraft will make an up-close visit to the small Comet Hartley 2, marking just the fifth time ever that a comet has been imaged from nearby.

It will be the second iceball encounter for Deep Impact, which served as mothership for a 2005 NASA mission that crashed a probe into Comet Tempel-1.

Comet Hartley 2 was discovered in 1986 by astronomer Malcolm Hartley, who spotted it while poring over photographic plates taken with the U.K. Schmidt Telescope at Siding Spring Observatory, near the town of Coonabarabran in New South Wales, Australia.

While Hartley primarily studies galaxies and other phenomena beyond our solar system, he discovered about 10 other comets — he has said he doesn't keep a faithful log — in a similar fashion.

NASA invited Hartley to partake in its flyby festivities at the agency's Jet Propulsion Lab (JPL) in Pasadena, Calif. SPACE.com caught up with Hartley to talk about comets, the thrill of discovery and what it's like to be the most famous person in Coonabarabran (population 2,600).

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