Re: [Utah-astronomy] Interest in "LCROSS Crunch" event?
Chuck, As to the Utah observing altitude, the nominal impact position is with the Moon over the Keck in HI. So, you're looking at 20 degs off the Utah southwest horizon. However, the MMT Observatory on Mt. Hopkins in Arizona and Gemini South in Chile are secondary participating telecopes. If HI is weather socked out, the LCROSS team may slip the impact time forward and use scopes on Utah's longitude as the primary spectroscopy data gatherers. (Don't count too much on this one; my impression is the LCROSS team is really set on using the Keck and IRTF.) As to lunar phase, once the target crater is selected finally, the impact will be timed so the crater is just inside the dark side of the terminator. This is necessary to have the impact plume rise up 10 kilometers into the sunlight where the sun's energy will generate enough of a spectroscopic signature in the dust to be gathered on Earth. But the illuminated plume also has to be framed against the dark background of the night sky behind the Moon. If the plume rises within bright side of the terminator, the spectroscopic signal gets washed out. MIssion parameters allow the impact anytime between lunar disk illuminated fractions of 37% to 93%, but again, with the target crater just inside the terminator. Various amateur (and one by the LCROSS team investigator) of the likely target sites between these illuminations can be found here: http://groups.google.com/group/lcross_observation/web/index-to-images and at Jim Mosher's informal LCROSS wiki pages: http://ltvt.wikispaces.com/LCROSS http://ltvt.wikispaces.com/LCROSS#toc5 The LCROSS team lead astronomer has time reserved on the IRTF on July 1 for northern lunar hemisphere observing. This has not been announced for amateur concurrent imaging (as occurred in Dec. and Jan.). But Jim's wiki page on the training session will give you some impressions of the illumination involved at impact: http://ltvt.wikispaces.com/LCROSS+Jul+2009+Campaign The only thing that firmed up in the last six months is that the current launch dates necessarily imply an impact at the southern polar region, not the north. Clear Skies - Kurt Participating observatories http://www.nasa.gov/centers/ames/news/releases/2009/09-09AR.html Informal LCROSS Faq, questions 15 (lighting conditions) and 10 (participating observatories) http://groups.google.com/group/lcross_observation/web/lcross-faq
I wonder if your camcorder would even work on the Grim. Is the focus point the same as for most eyepeices? It might be interesting to hook it up prior to Star Party and project Saturn or Jupiter on a computer screen. Perhaps there will be an event to podcast sometime.
Chuck, As to the Utah observing altitude, the nominal impact position is with the Moon over the Keck in HI. So, you're looking at 20 degs off the Utah southwest horizon. However, the MMT Observatory on Mt. Hopkins in Arizona and Gemini South in Chile are secondary participating telecopes. If HI is weather socked out, the LCROSS team may slip the impact time forward and use scopes on Utah's longitude as the primary spectroscopy data gatherers. (Don't count too much on this one; my impression is the LCROSS team is really set on using the Keck and IRTF.) As to lunar phase, once the target crater is selected finally, the impact will be timed so the crater is just inside the dark side of the terminator. This is necessary to have the impact plume rise up 10 kilometers into the sunlight where the sun's energy will generate enough of a spectroscopic signature in the dust to be gathered on Earth. But the illuminated plume also has to be framed against the dark background of the night sky behind the Moon. If the plume rises within bright side of the terminator, the spectroscopic signal gets washed out. MIssion parameters allow the impact anytime between lunar disk illuminated fractions of 37% to 93%, but again, with the target crater just inside the terminator.
Various amateur (and one by the LCROSS team investigator) of the likely target sites between these illuminations can be found here: http://groups.google.com/group/lcross_observation/web/index-to-images and at Jim Mosher's informal LCROSS wiki pages: http://ltvt.wikispaces.com/LCROSS http://ltvt.wikispaces.com/LCROSS#toc5
The LCROSS team lead astronomer has time reserved on the IRTF on July 1 for northern lunar hemisphere observing. This has not been announced for amateur concurrent imaging (as occurred in Dec. and Jan.). But Jim's wiki page on the training session will give you some impressions of the illumination involved at impact:
http://ltvt.wikispaces.com/LCROSS+Jul+2009+Campaign
The only thing that firmed up in the last six months is that the current launch dates necessarily imply an impact at the southern polar region, not the north.
Clear Skies - Kurt
Participating observatories http://www.nasa.gov/centers/ames/news/releases/2009/09-09AR.html
Informal LCROSS Faq, questions 15 (lighting conditions) and 10 (participating observatories) http://groups.google.com/group/lcross_observation/web/lcross-faq
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One has to wonder why the hundreds of pounds of actual moon brought back can't give us the compositional information that the spectrum of a dust cloud supposedly will. Is all this for the signature of a few molecules of water vapor? Erik, I promise you that the Grim has enough focus to accommodate my little camera. If it can focus with that 55mm eyepiece, it can focus with anything. Ideally I need to machine a thread-on adapter first. I would project it onto my 7" portable flatscreen in real-time. You could view it on a computer after I download and convert the files.
On 08 Jun 2009, at 17:28, Chuck Hards wrote:
One has to wonder why the hundreds of pounds of actual moon brought back can't give us the compositional information that the spectrum of a dust cloud supposedly will. Is all this for the signature of a few molecules of water vapor?
I don't think any of the lunar material we or the Soviets brought back from the Moon came from anywhere near the perpetually dark areas of the Moon where water ice might exist. So, yes, I believe the primary reason for this mission is to look for water ice.
Erik, I promise you that the Grim has enough focus to accommodate my little camera. If it can focus with that 55mm eyepiece, it can focus with anything. Ideally I need to machine a thread-on adapter first.
If in fact you can achieve focus I did have adapters made a couple of years back that fit in the Ealing, refractor and Grim scopes' draw tubes and onto which accessories can be threaded. But those were made in the days before Bruce moved the Ealing and Grim primary mirrors (see my post from earlier this evening about that) so they may now work only in the refractor. patrick
Even if "in" travel is needed, all you have to currently do on the Grim is remove the 2" diagonal. That gives you 40mm-50mm of in travel, and eliminates 25% of the throughput loss to reflection. The view is reversed left-for-right in that instance, but that's not a problem. Just like viewing through a SCT with a star diagonal. Easily corrected on the computer. On Mon, Jun 8, 2009 at 9:49 PM, Patrick Wiggins <paw@wirelessbeehive.com>wrote:
If in fact you can achieve focus I did have adapters made a couple of years back that fit in the Ealing, refractor and Grim scopes' draw tubes and onto which accessories can be threaded. But those were made in the days before Bruce moved the Ealing and Grim primary mirrors (see my post from earlier this evening about that) so they may now work only in the refractor.
Thinking about it, the amount of travel gained without the diagonal is probably closer to 75mm. Plenty, even for a digital SLR. Going "on the cheap", one could use one of those "digital eyepieces" and make an adapter that allows it to slide INSIDE the 2" focuser drawtube. Presto- all the "in" travel needed; instant video astronomy for the masses. Reminds me of when I shot video of SL-9 impacting Jupiter. Fun project. On Tue, Jun 9, 2009 at 10:59 AM, Chuck Hards <chuck.hards@gmail.com> wrote:
Even if "in" travel is needed, all you have to currently do on the Grim is remove the 2" diagonal. That gives you 40mm-50mm of in travel, and eliminates 25% of the throughput loss to reflection. The view is reversed left-for-right in that instance, but that's not a problem. Just like viewing through a SCT with a star diagonal. Easily corrected on the computer.
It's too bad the Clementine data was inconclusive on this. I think planners of lunar occupation had better start coming up with scenarios with no available lunar water resources. It's obviously not there in the huge quantities once theorized. On Mon, Jun 8, 2009 at 9:49 PM, Patrick Wiggins <paw@wirelessbeehive.com>wrote:
I don't think any of the lunar material we or the Soviets brought back from the Moon came from anywhere near the perpetually dark areas of the Moon where water ice might exist. So, yes, I believe the primary reason for this mission is to look for water ice.
On 08 Jun 2009, at 14:39, erikhansen@TheBlueZone.net wrote:
I wonder if your camcorder would even work on the Grim. Is the focus point the same as for most eyepeices? It might be interesting to hook it up prior to Star Party and project Saturn or Jupiter on a computer screen. Perhaps there will be an event to podcast sometime.
Y'all might want to check with Bruce about that. The way I understand it he recently moved the primary back so there would not have to be so many extension tubes behind the eyepiece to achieve focus and that pretty well eliminated the ability to focus a camera (well, unless a barlow is used). patrick
Guys, shooting afocally, there is no required in-travel needed. Relax. On Mon, Jun 8, 2009 at 9:27 PM, Patrick Wiggins <paw@wirelessbeehive.com>wrote:
On 08 Jun 2009, at 14:39, erikhansen@TheBlueZone.net wrote:
I wonder if your camcorder would even work on the Grim. Is the focus
point the same as for most eyepeices? It might be interesting to hook it up prior to Star Party and project Saturn or Jupiter on a computer screen. Perhaps there will be an event to podcast sometime.
Y'all might want to check with Bruce about that. The way I understand it he recently moved the primary back so there would not have to be so many extension tubes behind the eyepiece to achieve focus and that pretty well eliminated the ability to focus a camera (well, unless a barlow is used).
participants (4)
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Canopus56 -
Chuck Hards -
erikhansen＠TheBlueZone.net -
Patrick Wiggins