LCROSS Centaur Impact Flash (2009 Oct 10)

[geckzilla]

So there was a flash, after all. That lower right enlargement is kind of obscure. I can't tell what it is. It's supposed to be the impact, according to the description, but I'm not making the connection between it and the main picture.

http://apod.nasa.gov/apod/ap091010.html


...

Let's start a pool. The one who picks the decade when photos of the impact on the moon of the $79 mil ice-seeking probe first show up on APOD wins.

I'm gonna put my wager up for never, since no images of the impact seem to exist.

Shucks, I just lost my wager. (By the way, this is the silliest emoticon ever to indicate laughter)

Final silly fact: This thread pushed the epic global warming thread off the front page. How long until it is resurrected again?

[jerbil]

And now we all look forward to the analysis. For all the standard reasons I always doubted the existence of surface ice on the Moon (lack of an atmosphere, low gravity, high Noon temperatures, and so on.) Of course, in my lack of wisdom and foresight, I completely neglected what might be going on in a crater at one of the lunar poles, nor did I properly consider the effects of icy meteorites or comet remnants impacting on the lunar surface.

[neufer]

Let's start a pool. The one who picks the decade when photos of the impact on the moon of the $79 mil ice-seeking probe first show up on APOD wins.

I'm gonna put my wager up for never, since no images of the impact seem to exist.

Shucks, I just lost my wager. (By the way, this is the silliest emoticon ever to indicate laughter)

Final silly fact: This thread pushed the epic global warming thread off the front page. How long until it is resurrected again?

If you were the man in the moon and was just tickled under the chin how would you look?

[neufer]

So there was a flash, after all. That lower right enlargement is kind of obscure. I can't tell what it is. It's supposed to be the impact, according to the description, but I'm not making the connection between it and the main picture.

http://apod.nasa.gov/apod/ap091010.html

Graphics from the LCROSS press briefing
By Emily Lakdawalla Oct. 9, 2009

LCROSS mid-infrared view of the lunar south pole "flipped"

LCROSS captured this image of the lunar south pole on its way into impact on October 9, 2009. It watched the Centaur upper stage crash into a permanently shadowed area of the crater Cabeus. This version of the image has been mirror-reversed in order to match the appearance of the visible- and near-infrared camera images.Credit: NASA / ARC / processed by Emily Lakdawalla
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Impact flash detected by LCROSS mid-infrared camera "upsampled"

This image presents three different zooms into the same image captured by LCROSS' mid-infrared camera just after the impact of the Centaur upper stage into the crater Cabeus on October 9, 2009 at 11:31 UTC. The flash was visible in thermal wavelengths, and was spread over several pixels in the camera image, which surprised the principal investigator. The version at lower right has been "upsampled" significantly -- in reality there were only three or four pixels across the flash area.Credit: NASA / ARC
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LCROSS mid-infrared detection of Centaur impact flash "sampled"

The version of the mid-infrared impact detection shown on NASA Television was not upsampled, so it is clear how the impact flash was observed to spread across several pixels, a fact that was surprising to the project scientist. Anthony Colaprete mused that it could represent motion smear, but the frame rate of the camera was high enough to make that seem unlikely to him. Credit: NASA TV; courtesy klausd of raumfahrer.net

[rstevenson]

The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny..." -- Isaac Asimov

[geckzilla]

Conversely, that's one of the worst things you can hear your doctor say as his patient.

May we live in interesting times.

[kovil]

Many thanks Art (neufer) for the great photos !!!

I watched the live NASA, but it was somewhat disappointing for 'action', tho they hit their target and all systems functioned well.

Remember, these images are in the infrared, which shows kinetic energy's translation into the EM spectrum, best.
Visible light spectrum shows the 'presence' of matter best.
Thus NASA's chioce of wavelengths for the LCROSS imaging.

As the booster was in a slow 'tumble' so as to impact at an angle, rather than 'on end' or 'flat', for the biggest 'splash' so to speak, the 3 pixel infrared register of energy signature indicates a 'good' angular impact pattern ! Bravo ! This mission was a resounding success on several levels. Hardware, software, cost, and good luck -thru good preparation !

Personally, I expect a low water presence, which will be disappointing for habitation requirements. As comets are exactly the same composition as asteroids (comets are NOT dirty ice balls) they contribute no water to the Moon when they are accumulated by the Moon. Solar wind particulate is likely the culpret for the 'hydrogen presence' detected by previous satellite imagery, and is most likely an extremely thin and tenuous veil upon the lunar surface only.

It will be interesting to see what LCROSS detected in the ejecta thrown up from the booster's impact !
Manganese, titanium, hydroxls, hydrocarbons, silicates ? We eagerly await the results. Good work guys !!!

[Chris Peterson]

Remember, these images are in the infrared, which shows kinetic energy's translation into the EM spectrum, best.
Visible light spectrum shows the 'presence' of matter best.
Thus NASA's chioce of wavelengths for the LCROSS imaging.

The visible light spectrum and infrared are both EM, and not at all far apart in wavelength. Where the peak wavelength lies is determined by the temperature of the products of the collision, and can just as easily be in the visible wavelengths as the IR. In this case, the collisional energy is pretty low (less than 1e10 joules), so I expect the anticipated temperatures were low as well, hence the decision to include IR observations. IR was used for the Earth-based observations primarily because this is required by adaptive optics systems used to boost resolution.

As comets are exactly the same composition as asteroids (comets are NOT dirty ice balls) they contribute no water to the Moon when they are accumulated by the Moon.

Comets and asteroids are certainly not the same composition. It is possible, but unlikely, that their rocky components are similar. But comets contain substantial amounts of volatiles, mainly ices of methane, water, and carbon dioxide. These are not found in asteroids except in trace quantities, if at all. There is no doubt at all that comets contain large amounts of water, and that comets colliding with any large body will contribute that water. Whether the water from comets remains on the Moon is a complicated question, one which LCROSS is designed to investigate.

[jerbil]

It might be maintained that a meteorite is either rocky or iron-nickel, but surely our knowledge is based on that which arrives at the surface of the Earth, from which any volatiles may have disappeared. But what about Kuiper belt objects, or even objects in the Oort cloud?

[Chris Peterson]

It might be maintained that a meteorite is either rocky or iron-nickel, but surely our knowledge is based on that which arrives at the surface of the Earth, from which any volatiles may have disappeared. But what about Kuiper belt objects, or even objects in the Oort cloud?

Most meteorites are asteroidal, meaning they come from material in the asteroid belt. Such material can be stony, iron, or a mixture of the two. Many meteors have been recorded that reveal parent bodies with cometary characteristics; none have produced any meteorite recoveries. Most investigators think that the non-volatile material in comets (which is likely to be similar to KBOs and Oort objects) is similar or identical to carbonaceous chondrites, but this is largely untested. The lack of any known cometary material for examination means all of this remains quite speculative.

[neufer]

Remember, these images are in the infrared, which shows kinetic energy's translation into the EM spectrum, best.
Visible light spectrum shows the 'presence' of matter best.
Thus NASA's chioce of wavelengths for the LCROSS imaging.

The visible light spectrum and infrared are both EM, and not at all far apart in wavelength. Where the peak wavelength lies is determined by the temperature of the products of the collision, and can just as easily be in the visible wavelengths as the IR. In this case, the collisional energy is pretty low (less than 1e10 joules), so I expect the anticipated temperatures were low as well, hence the decision to include IR observations. IR was used for the Earth-based observations primarily because this is required by adaptive optics systems used to boost resolution.

Mid-infrared (3-8 µm) is equally sensitive to room temperature & to reflected sunlight
but it is particularly sensitive to thermal temperatures around 600º C
http://cimss.ssec.wisc.edu/goes/rt/view ... ct=gsc_b17

Mid-infrared is used for earth-based observations primarily to:
1) detect the thermal signature of fires
2) see best through water vapor & cirrus clouds and
3) distinguish white snow from white clouds.

The ends of the mid-infrared are particularly sensitive to
1) ice [3 µm] and 2) water vapor [5-8 µm]

[ta152h0]

I shoul call the guy on channel 13 news,here in Seattle and show these images. He was asking his coworkers if the moon was going to be around after the impact. Maybe tv anchors should stick to commenting how pretty they are.

[apodman]

He was asking his coworkers if the moon was going to be around after the impact.

When I was a wee lad, I told my dad that whoever wrote my horoscope mistook me for a character in a western. After having a look for himself, my father explained it was co-workers, not cow-workers. The word still looks funny to me.

[ta152h0]

I just had cataract surgery so I am sure this is not the last time.

[iamlucky13]

Personally, I expect a low water presence, which will be disappointing for habitation requirements. As comets are exactly the same composition as asteroids (comets are NOT dirty ice balls) they contribute no water to the Moon when they are accumulated by the Moon. Solar wind particulate is likely the culpret for the 'hydrogen presence' detected by previous satellite imagery, and is most likely an extremely thin and tenuous veil upon the lunar surface only.

I'd suggest reading this section (which does include citations) from the wikipedia article on comets:
http://en.wikipedia.org/wiki/Comet#Deba ... omposition

I think you might be misunderstanding somewhat the implications of the recent comet studies that have led to the "dirty snowball" description falling out of favor. It's not that there is no water or other volatiles in them, but that the surfaces appear to be dry and the overall proportion of water lower than initially believed.

Also, even some meteoroids (carbonaceous chondrites) contain volatiles including water.

[DavidLeodis]

In the explanation to the APOD it states the Centaur rocket hit the lunar surface "at 4:31am UT". Should that be 4:31am PDT (Pacific Daylight Time) not 4:31am UT (Universal Time).

[Orca]

Remember, these images are in the infrared, which shows kinetic energy's translation into the EM spectrum, best.
Visible light spectrum shows the 'presence' of matter best.
Thus NASA's chioce of wavelengths for the LCROSS imaging.

The visible light spectrum and infrared are both EM, and not at all far apart in wavelength. Where the peak wavelength lies is determined by the temperature of the products of the collision, and can just as easily be in the visible wavelengths as the IR. In this case, the collisional energy is pretty low (less than 1e10 joules), so I expect the anticipated temperatures were low as well, hence the decision to include IR observations. IR was used for the Earth-based observations primarily because this is required by adaptive optics systems used to boost resolution.

Mid-infrared (3-8 µm) is equally sensitive to room temperature & to reflected sunlight
but it is particularly sensitive to thermal temperatures around 600º C
http://cimss.ssec.wisc.edu/goes/rt/view ... ct=gsc_b17

Mid-infrared is used for earth-based observations primarily to:
1) detect the thermal signature of fires
2) see best through water vapor & cirrus clouds and
3) distinguish white snow from white clouds.

The ends of the mid-infrared are particularly sensitive to
1) ice [3 µm] and 2) water vapor [5-8 µm]

A simple and fun demonstration: take your cell phone camera and your TV remote. Point the remote back toward yourself and the outstretched camera. Push buttons. Your camera will detect the IR signals that your eyes can't see! The remote's IR LED's look like flashing white lights on the screen while remaining black as always to the naked eye.

[Chris Peterson]

A simple and fun demonstration: take your cell phone camera and your TV remote. Point the remote back toward yourself and the outstretched camera. Push buttons. Your camera will detect the IR signals that your eyes can't see! The remote's IR LED's look like flashing white lights on the screen while remaining black as always to the naked eye.

You are talking about near IR here, not mid- or far IR. A good camera won't be sensitive to this, because it is filtered out before it can reach the sensor. Otherwise, the color balance is messed up. But cellphone cameras are often of poor quality, so this would be a good type to try this experiment with.

The emitter on the remote control is probably putting out IR around 800nm. Your eye actually has some sensitivity here, just really low. But if the remote is a bright one, you may be able to see the IR coming out of it. Hold it close to your eye and look right at the emitter. You might notice a dim red signal. That's the IR output; you see it as red because only the red receptors of your eye are stimulated, and you see it as dim because your sensitivity to such a long wavelength is quite low.

[neufer]

A simple and fun demonstration: take your cell phone camera and your TV remote. Point the remote back toward yourself and the outstretched camera. Push buttons. Your camera will detect the IR signals that your eyes can't see! The remote's IR LED's look like flashing white lights on the screen while remaining black as always to the naked eye.

You are talking about near IR here, not mid- or far IR. A good camera won't be sensitive to this, because it is filtered out before it can reach the sensor. Otherwise, the color balance is messed up. But cellphone cameras are often of poor quality, so this would be a good type to try this experiment with.

The emitter on the remote control is probably putting out IR around 800nm. Your eye actually has some sensitivity here, just really low. But if the remote is a bright one, you may be able to see the IR coming out of it. Hold it close to your eye and look right at the emitter. You might notice a dim red signal. That's the IR output; you see it as red because only the red receptors of your eye are stimulated, and you see it as dim because your sensitivity to such a long wavelength is quite low.

Optical Inventions That Fueled the Information Age
The Washington Post / Monday, October 12, 2009

<<This year's Nobel Prize in physics was shared by Charles K. Kao for his development of low-loss optical fiber
and the team of Willard S. Boyle and George E. Smith, who invented the charge- coupled device.>>

[robotwisdom]

How wide was the flash?

[Orca]

A simple and fun demonstration: take your cell phone camera and your TV remote. Point the remote back toward yourself and the outstretched camera. Push buttons. Your camera will detect the IR signals that your eyes can't see! The remote's IR LED's look like flashing white lights on the screen while remaining black as always to the naked eye.

You are talking about near IR here, not mid- or far IR. A good camera won't be sensitive to this, because it is filtered out before it can reach the sensor. Otherwise, the color balance is messed up. But cellphone cameras are often of poor quality, so this would be a good type to try this experiment with.

The emitter on the remote control is probably putting out IR around 800nm. Your eye actually has some sensitivity here, just really low. But if the remote is a bright one, you may be able to see the IR coming out of it. Hold it close to your eye and look right at the emitter. You might notice a dim red signal. That's the IR output; you see it as red because only the red receptors of your eye are stimulated, and you see it as dim because your sensitivity to such a long wavelength is quite low.

True, I assumed the IR wavelength from a remote had to be close to the visible part of the spectrum, it's just a great illustration I think. It's a bit like turning on a heating element on your stove with the lights out...the deep hint of glow as the emitted EM radiation just barely begins to pass into visible wavelengths.



This experiment is also a "nerd test." If, after the first time seeing your remote's LED's in your camera, you say, "Woah, that's cool" and show all your friends, you're officially a nerd. I passed the nerd test with flying colors, not content with simply showing friends but also trying out several remotes and several cameras.

[neufer]

This experiment is also a "nerd test." If, after the first time seeing your remote's LED's in your camera, you say, "Woah, that's cool" and show all your friends, you're officially a nerd. I passed the nerd test with flying colors, not content with simply showing friends but also trying out several remotes and several cameras.

Haven't we already passed the "nerd test" by subscribing to _The Asterisk*_ ?

I object to any further qualifications!
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• Those with telescopes might try flashing their remote's LED into the eyepiece and see how far away you can detect the telescopic signal with your camera. Near IR should penetrate haze better than normal light.

<<IR images owe their great clarity to the atmosphere's exceptional transparency in the NIR. Scattering by air molecules is much less efficient at NIR than at most visible wavelengths. As a result, NIR photons take on average a much straighter path from object to CCD.

In visible light , scattering severely limits detail on the more distant portions of the far hillside in this hazy afternoon scene. Removing visible light with a Hoya R72 IR filter takes out much of the detail-scrambling scatter. An impressive amount of detail shines through the haze in the IR image, despite the odd false-color scheme.

[Orca]

This experiment is also a "nerd test." If, after the first time seeing your remote's LED's in your camera, you say, "Woah, that's cool" and show all your friends, you're officially a nerd. I passed the nerd test with flying colors, not content with simply showing friends but also trying out several remotes and several cameras.

Haven't we already passed the "nerd test" by subscribing to _The Asterisk*_ ?

I object to any further qualifications!

True, The Asterisk is a fine test, but it's always important to verify your results...

[DavidLeodis]

In the explanation to the APOD it states the Centaur rocket hit the lunar surface "at 4:31am UT". Should that be 4:31am PDT (Pacific Daylight Time) not 4:31am UT (Universal Time).

I've noticed that the error has been corrected and it now correctly states 11:31 UT.

[robotwisdom]

How wide was the flash?

Very important question!

As best I can guestimate using Google Earth's Moon map (which appears inverted compared to this APOD image), the round crater below the flash is about ten miles wide, so the flash is one-half to one mile in diameter.