APOD: Rosetta's Target Comet (2014 May 23)

Comments and questions about the APOD on the main view screen.
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APOD: Rosetta's Target Comet (2014 May 23)

Post by APOD Robot » Fri May 23, 2014 4:09 am

Image Rosetta's Target Comet

Explanation: The Rosetta spacecraft captured this remarkable series of 9 frames between March 27 and May 4, as it closed from 5 million to 2 million kilometers of its target comet. Cruising along a 6.5 year orbit toward closest approach to the Sun next year, periodic comet 67P/Churyumov-Gerasimenko is seen moving past a distant background of stars in Ophiuchus and globular star cluster M107. The comet's developing coma is actually visible by the end of the sequence, extending for some 1300 km into space. Rosetta is scheduled for an early August rendezvous with the comet's nucleus. Now clearly active, the nucleus is about 4 kilometers in diameter, releasing the dusty coma as its dirty ices begin to sublimate in the sunlight. The Rosetta lander's contact with the surface of the nucleus is anticipated in November.

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by bystander » Fri May 23, 2014 4:15 am

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by geckzilla » Fri May 23, 2014 4:52 am

Should be some pretty cool photos of the comet's nucleus when Philae lands on it. Landing on something with such low surface gravity has its own challenges. How many engineers does it take to screw in a Philae? http://www.esa.int/spaceinvideos/Videos ... touch_down
Just call me "geck" because "zilla" is like a last name.

DougF

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by DougF » Fri May 23, 2014 4:57 am

Hi
I am curios what are all the other flashing lights in the photos
Doug

melikamp

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by melikamp » Fri May 23, 2014 5:12 am

M107, not M104

http://www.esa.int/spaceinimages/Images ... n_30_April

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by ShaileshS » Fri May 23, 2014 6:22 am

DougF wrote:Hi
I am curios what are all the other flashing lights in the photos
Doug
+1 for DougF's question.
I am hoping some experts will shed some light

m-alex

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by m-alex » Fri May 23, 2014 6:23 am

What are these dot spots appearing in some iamge of the sequence ? is it noise ?
Alex

Camiel Plevier

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Camiel Plevier » Fri May 23, 2014 9:14 am

DougF wrote:Hi
I am curios what are all the other flashing lights in the photos
Doug
I was wondering the same thing. Could these be objects from the asteroid belt? It doesn't seem random noise to me.

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Boomer12k » Fri May 23, 2014 9:15 am

Very cool....

And M104 is the Sombrero Galaxy...no doubt a Typo....

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Guest » Fri May 23, 2014 9:18 am

melikamp wrote:...

P.S. finding astronomers' names for captcha is a REAL pain because I don't know some of the cheese names.
If it doesn't sound familiar, it's cheese. Tip: Use internet search to beef up your cheese and/or astronomers knowledge.

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by geckzilla » Fri May 23, 2014 11:10 am

DougF wrote:Hi
I am curios what are all the other flashing lights in the photos
Doug
Cosmic rays. These are high energy particles which strike the camera sensor but they are cleared off next time an image is taken so they only appear for one frame at a time. These are also what will give astronauts cancer if they are not careful. Sometimes they are so energetic that they can damage a camera sensor, creating a permanent bad pixel.
Just call me "geck" because "zilla" is like a last name.

Gruyere

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Gruyere » Fri May 23, 2014 11:15 am

Mmmmmmmmm ,,, gob-ular

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by BDanielMayfield » Fri May 23, 2014 11:43 am

geckzilla wrote:
DougF wrote:Hi
I am curios what are all the other flashing lights in the photos
Doug
Cosmic rays. These are high energy particles which strike the camera sensor but they are cleared off next time an image is taken so they only appear for one frame at a time. These are also what will give astronauts cancer if they are not careful. Sometimes they are so energetic that they can damage a camera sensor, creating a permanent bad pixel.
As someone who often processes these images taken by cameras in space these cosmic ray flashes must cause you grief too (not nearly as bad as cancer, of course) as you painstakingly remove them. How difficult is that process Geck?
Last edited by BDanielMayfield on Fri May 23, 2014 12:03 pm, edited 1 time in total.
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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by starsurfer » Fri May 23, 2014 11:45 am

If the globular cluster is M107, then the background starfield belongs to Ophiuchus.

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by owlice » Fri May 23, 2014 11:55 am

I've let the editors know re: Sagittarius and gobular star cluster M104.
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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by geckzilla » Fri May 23, 2014 11:57 am

BDanielMayfield wrote:As someone who often processes these images taken from cameras in space these cosmic ray flashes must cause you grief too (not nearly as bad as cancer, of course) as you painstakingly remove them. How difficult is that process Geck?
Depends on how many exposures there are. If there are a lot of exposures then it becomes largely automated. Fewer exposures results in uncertainty and a lot more manual removal. In cases where stars do not overlap between color channels such as when infrared light is used and many stars are invisible in shorter wavelengths, it is very difficult for me to make the distinction between a stellar point source and a cosmic ray which struck the sensor straight on. Hubble processing problems. :wink:
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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by BDanielMayfield » Fri May 23, 2014 12:17 pm

Thanks Geck. And here's a wish for clear skies for everyone in North America southeast of Alaska for tonight's possible meteor storm!
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Omaha science

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Omaha science » Fri May 23, 2014 1:15 pm

What is the star that winks on and off just to the right of the globular cluster in comet photo position 6 (by my count)?

Curious

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by geckzilla » Fri May 23, 2014 2:04 pm

Omaha science wrote:What is the star that winks on and off just to the right of the globular cluster in comet photo position 6 (by my count)?

Curious
All I see is a cosmic ray. It's one of the brighter ones.
Just call me "geck" because "zilla" is like a last name.

epszteinbenoit

Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by epszteinbenoit » Fri May 23, 2014 2:34 pm

Very helpful, Geck, it's highly appreciated!

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by RJN » Fri May 23, 2014 2:52 pm

starsurfer wrote:If the globular cluster is M107, then the background starfield belongs to Ophiuchus.
Yes, thank you. The APOD has now been updated with this more accurate information. We apologize for the oversights.

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by dickfrom1929 » Fri May 23, 2014 3:07 pm

M104 is the Sombrero galaxy in Corvus. I don't see comet 67P close to M107 in Starry Night Pro.

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Chris Peterson » Fri May 23, 2014 3:56 pm

dickfrom1929 wrote:M104 is the Sombrero galaxy in Corvus. I don't see comet 67P close to M107 in Starry Night Pro.
We're seeing it by M107, not M104. That said, however, you can't evaluate a picture like this using a planetarium program unless you change your viewpoint from Earth to Rosetta. The comet is currently in Sagittarius as seen from the Earth, but in Ophiuchus as seen from Rosetta.
Chris

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by MarkBour » Fri May 23, 2014 4:02 pm

Very nice sequence of images. It's surely a very exciting time for those who planned and executed this mission and have waited so long. I noticed that today (+/- 1) is listed as the "rendezvous" date in some of the materials describing this mission. Today's APOD ends with an image on May 4, about 19 days ago. You can clearly see the comet waking up and getting close. But if the Rosetta craft has now truly "reached" the comet, how long does it take for images to get here and to be processed for the awaiting public? I gather this will be a really wonderful ride. There's no substitute for being there!
Mark Goldfain

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Re: APOD: Rosetta's Target Comet (2014 May 23)

Post by Chris Peterson » Fri May 23, 2014 4:27 pm

MarkBour wrote:I noticed that today (+/- 1) is listed as the "rendezvous" date in some of the materials describing this mission.
That's confusing, isn't it? I think that what they are calling the "rendezvous" would be better described as the beginning of the rendezvous phase. The 21 May deceleration burn created the largest delta-V of any planned maneuvers. It began the process of putting the spacecraft in orbit.
Today's APOD ends with an image on May 4, about 19 days ago. You can clearly see the comet waking up and getting close. But if the Rosetta craft has now truly "reached" the comet, how long does it take for images to get here and to be processed for the awaiting public?
It hasn't reached the comet. Currently, the spacecraft is 27 light minutes from Earth (and 3 light seconds from the comet). ESA decides how quickly data is released, but it's generally almost immediately.
Chris

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