Imaging Opportunities at Impact lighting conditions
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XB70man
Jul 12, 2009, 2:04:40 PM7/12/09
to LCROSS_Observation
Over the next few months, there are some good opportunities to image
the south pole of the Moon at similar lighting and libration
conditions as on Impact Day. I urge everyone with high-resolution
planetary imaging capability to attempt a detailed image that can be
posted on the NASA website to guide would-be imagers/videographers to
the impact location. Many of the images posted on GoogleGroups had
positive lighting (Moon Waxing-to-Full) which would make locationg the
impact location with certainty difficult.
Table is for the West Coast (San Jose, CA) - but close enough for the
continental USA. Adjust times accordingly ---
Date Time (PDT) % Illum. Latitude Libration (°)
July 13 0:04:00am PDT -70.80 -4.89
(Tomorrow Morning!)
Aug 11 00:04:00am PDT -75.02 -5.95
Aug 11 05:04:00am PDT -73.65 -6.41
Aug 12 00:04:00am PDT -65.46 -6.06
Sep 10 00:04:00am PDT -69.01 -5.37
Oct 9 04:30:00am PDT -70.81 -3.59 IMPACT!
As you can see, tomorrow morning and September 10th are the closest
matches for lighting conditions.
A GUIDE CD-ROM screenshot of the south pole of the Moon for tomorrow
morning is at:
/group/lcross_observation/web/Guide%20LCROSS%2020090713%200004PST.jpg
Best of luck!
Rick Baldridge
LCROSS Google-Groups Moderator
the south pole of the Moon at similar lighting and libration
conditions as on Impact Day. I urge everyone with high-resolution
planetary imaging capability to attempt a detailed image that can be
posted on the NASA website to guide would-be imagers/videographers to
the impact location. Many of the images posted on GoogleGroups had
positive lighting (Moon Waxing-to-Full) which would make locationg the
impact location with certainty difficult.
Table is for the West Coast (San Jose, CA) - but close enough for the
continental USA. Adjust times accordingly ---
Date Time (PDT) % Illum. Latitude Libration (°)
July 13 0:04:00am PDT -70.80 -4.89
(Tomorrow Morning!)
Aug 11 00:04:00am PDT -75.02 -5.95
Aug 11 05:04:00am PDT -73.65 -6.41
Aug 12 00:04:00am PDT -65.46 -6.06
Sep 10 00:04:00am PDT -69.01 -5.37
Oct 9 04:30:00am PDT -70.81 -3.59 IMPACT!
As you can see, tomorrow morning and September 10th are the closest
matches for lighting conditions.
A GUIDE CD-ROM screenshot of the south pole of the Moon for tomorrow
morning is at:
/group/lcross_observation/web/Guide%20LCROSS%2020090713%200004PST.jpg
Best of luck!
Rick Baldridge
LCROSS Google-Groups Moderator
Derek C Breit
Jul 12, 2009, 8:05:55 PM7/12/09
to lcross_ob...@googlegroups.com
***I urge everyone with high-resolution planetary imaging capability to
attempt a detailed image that can be posted on the NASA website to guide
would-be imagers/videographers to the impact location.***
attempt a detailed image that can be posted on the NASA website to guide
AND!
Before you shut down, try and image stars near that bright Southern limb..
70.81 % illuminated is just beyond depressing..
It just so happens I will be out all night doing three "Mutual Events" (The
moons of Jupiter and Saturn eclipsing and occulting each other), Two
asteroid occultations, and a bright Lunar Occultation.. I'll grab a little
video of the moon..
Thanks Rick..
Derek
PS.. Rick.. August 14th I am dismounting the 12" from the wedge and going
mobile again.. A Nice graze of mag 3 Electra..
You, and everyone else, are invited to come with me..
Over the next few months, there are some good opportunities to image the
south pole of the Moon at similar lighting and libration conditions as on
Impact Day. I urge everyone with high-resolution planetary imaging
capability to attempt a detailed image that can be posted on the NASA
website to guide would-be imagers/videographers to the impact location.
Many of the images posted on GoogleGroups had positive lighting (Moon
Waxing-to-Full) which would make locating the impact location with certainty
difficult.
Table is for the West Coast (San Jose, CA) - but close enough for the
continental USA. Adjust times accordingly ---
Date Time (PDT) % Illum. Latitude Libration (°)
July 13 0:04:00am PDT -70.80 -4.89
(Tomorrow Morning!)
Aug 11 00:04:00am PDT -75.02 -5.95
Aug 11 05:04:00am PDT -73.65 -6.41
Aug 12 00:04:00am PDT -65.46 -6.06
Sep 10 00:04:00am PDT -69.01 -5.37
Oct 9 04:30:00am PDT -70.81 -3.59 IMPACT!
As you can see, tomorrow morning and September 10th are the closest matches
for lighting conditions.
A GUIDE CD-ROM screenshot of the south pole of the Moon for tomorrow morning
is at: /group/lcross_observation/web/Guide%20LCROSS%2020090713%200004PST.jpg
Best of luck!
Rick Baldridge
LCROSS Google-Groups Moderator --~--~---------~
Jim Mosher
Jul 15, 2009, 5:09:23 PM7/15/09
to lcross_ob...@googlegroups.com
Rick,
Is the "NASA website" you are referring to the main LCROSS site or the
one announced so long ago as being under development for uploading
amateur and professional images?
As to obtaining images, it would seem to me to be more productive to
look for images taken at past times when the lighting and librations
at the Moon's south pole approximated those expected on October 9th.
The fundamental problem is that a major determinant in polar lighting
is how far the Sun is north or south of the Moon's equator, and that
changes only gradually over the course of about a year. On October
9th, the Sun will be near 1.5°S on the Moon -- near the peak to the
southern summer. Trying to take photos now to show what the pole will
look like in October is something like taking satellite photos of the
Earth's north pole in Spring and hoping they will show what it will
look like when Summer comes.
In addition, waiting for the percent illumination of the Moon as whole
to reach some particular value is a poor indicator of lighting at any
specific point on the surface. The percent illumination when the
terminator passes through particular surface features can differ
widely depending on the libration in longitude. Think, for example,
of a situation with the terminator passing through Ptolemaeus:
depending on the libration in longitude, Ptolemaeus can be well to the
east or west of the central meridian -- hence the illumination of the
Moon as a whole (as seen from Earth) can be more or less than 50%.
The attachment giving times when the lighting at the near-polar crater Haworth:
http://the-moon.wikispaces.com/Haworth
will resemble those on October 9th may be helpful. The most recent
time at which the lighting angle and libration in latitude resembled
the desired ones was October 20, 2008 at 00:37 UT. There were
undoubtedly many photos taken that day, but I know of only one -- see
the links to Mario Weigand's image at:
http://ltvt.wikispaces.com/LCROSS+Impact
To get a close match in lighting, libration in latitude AND libration
in longitude one has to go back to September 29, 1991 at 03:48 UT.
Again, I would not be surprised to find that many photos of the Moon
were taken that day (most likely on film rather than digitally), but
how one locates them is a puzzle, at least to me.
By the way, the attachment gives (towards the end of each line) the
percent illumination at these moments when the lighting at Haworth is
similar to that to be found on October 9th. As expected, the
illumination is near 71% only on those occasions when the libration in
longitude is close to the October 9th value.
The July and August 2009 dates do not appear in this printout because
the Sun, at those times, is too far north to attain the summery
heights over the south pole that it will reach in October.
-- Jim
Is the "NASA website" you are referring to the main LCROSS site or the
one announced so long ago as being under development for uploading
amateur and professional images?
As to obtaining images, it would seem to me to be more productive to
look for images taken at past times when the lighting and librations
at the Moon's south pole approximated those expected on October 9th.
The fundamental problem is that a major determinant in polar lighting
is how far the Sun is north or south of the Moon's equator, and that
changes only gradually over the course of about a year. On October
9th, the Sun will be near 1.5°S on the Moon -- near the peak to the
southern summer. Trying to take photos now to show what the pole will
look like in October is something like taking satellite photos of the
Earth's north pole in Spring and hoping they will show what it will
look like when Summer comes.
In addition, waiting for the percent illumination of the Moon as whole
to reach some particular value is a poor indicator of lighting at any
specific point on the surface. The percent illumination when the
terminator passes through particular surface features can differ
widely depending on the libration in longitude. Think, for example,
of a situation with the terminator passing through Ptolemaeus:
depending on the libration in longitude, Ptolemaeus can be well to the
east or west of the central meridian -- hence the illumination of the
Moon as a whole (as seen from Earth) can be more or less than 50%.
The attachment giving times when the lighting at the near-polar crater Haworth:
http://the-moon.wikispaces.com/Haworth
will resemble those on October 9th may be helpful. The most recent
time at which the lighting angle and libration in latitude resembled
the desired ones was October 20, 2008 at 00:37 UT. There were
undoubtedly many photos taken that day, but I know of only one -- see
the links to Mario Weigand's image at:
http://ltvt.wikispaces.com/LCROSS+Impact
To get a close match in lighting, libration in latitude AND libration
in longitude one has to go back to September 29, 1991 at 03:48 UT.
Again, I would not be surprised to find that many photos of the Moon
were taken that day (most likely on film rather than digitally), but
how one locates them is a puzzle, at least to me.
By the way, the attachment gives (towards the end of each line) the
percent illumination at these moments when the lighting at Haworth is
similar to that to be found on October 9th. As expected, the
illumination is near 71% only on those occasions when the libration in
longitude is close to the October 9th value.
The July and August 2009 dates do not appear in this printout because
the Sun, at those times, is too far north to attain the summery
heights over the south pole that it will reach in October.
-- Jim
Arnold Ashcraft
Jul 15, 2009, 7:23:48 PM7/15/09
to lcross_ob...@googlegroups.com, Jim Mosher
Jim:
Looks like we need to all go through our files and find photos taken
on dates that match all the relevant lunar illumination and
orientation parameters. The Virtual Moon Atlas program will compute
all these quantities for a specific date, and it's free for
downloading at:
http://www.ap-i.net/avl/en/download
Attached are two screen shots of the parameters computed under the
ephemeris tab of the program, one for today and the other for october
9. I believe the quantity "solar inclination" is how far the sun is
above or below the equator, ie, the season on the moon. As I
understand it, we need to match libration in both latitude and
longitude, solar inclination and phase. Am I missing anything?
Clif
Looks like we need to all go through our files and find photos taken
on dates that match all the relevant lunar illumination and
orientation parameters. The Virtual Moon Atlas program will compute
all these quantities for a specific date, and it's free for
downloading at:
http://www.ap-i.net/avl/en/download
Attached are two screen shots of the parameters computed under the
ephemeris tab of the program, one for today and the other for october
9. I believe the quantity "solar inclination" is how far the sun is
above or below the equator, ie, the season on the moon. As I
understand it, we need to match libration in both latitude and
longitude, solar inclination and phase. Am I missing anything?
Clif
Jim Mosher
Jul 15, 2009, 8:14:08 PM7/15/09
to LCROSS_Observation
Hi Cliff!
No, I don't think you're missing anything.
Hopefully the list I attached to the earlier message will pinpoint
past dates and times with lighting at the same angle and from the same
direction as it will be on October 9th. Finding times when the
librations are similar as well is tricky, but only the dates appearing
on the list offer a near-exact match in lighting.
I suspect the VMA authors use the term "solar inclination" for the
Sun's latitude north or south of the equator because when the Sun is
to the north or south it "inclines" the terminator by that amount
relative to meridians of constant longitude (I call it the latitude of
the sub-solar point in my own listings). The maximum inclination is
much less than the the 23.5 deg that generates the Earth's seasons,
but it still affects the polar lighting.
Although its a small point, one word of caution about VMA: you have to
be careful about its handling of daylight savings time. VMA will
probably assume the offset from your local clock time to UT is the
same as whatever it currently happens to be -- and that can easily
lead to results that are off by an hour for past and future times.
The UT assumed by VMA is listed on the "Date (DT)" line in the
screenshots you attached. You may wish to check that it's correct
(especially if you have entered a date from a past year). If it's a
problem, there is a "Configuration" screen where you can tell the
program to operate in UT, and enter the correct UT yourself.
-- Jim
> VMAephemeristab.jpg
> 96KViewDownload
>
>
>
> VMAephemerisoct9.jpg
> 94KViewDownload
> > <Haworth_lighting.txt>
No, I don't think you're missing anything.
Hopefully the list I attached to the earlier message will pinpoint
past dates and times with lighting at the same angle and from the same
direction as it will be on October 9th. Finding times when the
librations are similar as well is tricky, but only the dates appearing
on the list offer a near-exact match in lighting.
I suspect the VMA authors use the term "solar inclination" for the
Sun's latitude north or south of the equator because when the Sun is
to the north or south it "inclines" the terminator by that amount
relative to meridians of constant longitude (I call it the latitude of
the sub-solar point in my own listings). The maximum inclination is
much less than the the 23.5 deg that generates the Earth's seasons,
but it still affects the polar lighting.
Although its a small point, one word of caution about VMA: you have to
be careful about its handling of daylight savings time. VMA will
probably assume the offset from your local clock time to UT is the
same as whatever it currently happens to be -- and that can easily
lead to results that are off by an hour for past and future times.
The UT assumed by VMA is listed on the "Date (DT)" line in the
screenshots you attached. You may wish to check that it's correct
(especially if you have entered a date from a past year). If it's a
problem, there is a "Configuration" screen where you can tell the
program to operate in UT, and enter the correct UT yourself.
-- Jim
> 96KViewDownload
>
>
>
> VMAephemerisoct9.jpg
> 94KViewDownload
cano...@yahoo.com
Jul 15, 2009, 9:32:29 PM7/15/09
to LCROSS_Observation
On Jul 12, 12:04 pm, XB70man <rickbaldri...@comcast.net> wrote:
<snip>
> I urge everyone with high-resolution planetary imaging capability to attempt
> a detailed image that can be posted on the NASA website to guide
> would-be imagers/videographers to the impact location.
As an amateur lunar observer with more Moon observing experience than
the average astronomy club member with a DSO emphasis, I second that
recommendation, notwithstanding that the illumination on the listed
dates may not precisely replicate illumination on the projected Oct. 9
impact date. As a self-described intermediate lunar observer, even I
was scratching my head at the eyepiece on the morning of July 13.
Most amateurs look at the Moon during waning, not waxing
illumination. I had to pull out Rukls and consult a few images here
and on Jim's site before I was sure I could correctly identify key
features. I'll be taking a peak and trying to take an image on August
11-12 and Sept. 10. Hopefully, on those dates, when I hook up my
(new) power inverter to the spare car battery, smoke will not start
pouring out of it as occurred on July 13. -:) On the plus side, after
sitting through the July 13 date visually, I was less concerned about
the closeness of the impact time to advancing nautical twilight. The
sky was still dark at the Moon's altitude even though astronomical
twilight could be seen at the horizon. Clear Skies - Kurt
<snip>
> I urge everyone with high-resolution planetary imaging capability to attempt
> a detailed image that can be posted on the NASA website to guide
> would-be imagers/videographers to the impact location.
the average astronomy club member with a DSO emphasis, I second that
recommendation, notwithstanding that the illumination on the listed
dates may not precisely replicate illumination on the projected Oct. 9
impact date. As a self-described intermediate lunar observer, even I
was scratching my head at the eyepiece on the morning of July 13.
Most amateurs look at the Moon during waning, not waxing
illumination. I had to pull out Rukls and consult a few images here
and on Jim's site before I was sure I could correctly identify key
features. I'll be taking a peak and trying to take an image on August
11-12 and Sept. 10. Hopefully, on those dates, when I hook up my
(new) power inverter to the spare car battery, smoke will not start
pouring out of it as occurred on July 13. -:) On the plus side, after
sitting through the July 13 date visually, I was less concerned about
the closeness of the impact time to advancing nautical twilight. The
sky was still dark at the Moon's altitude even though astronomical
twilight could be seen at the horizon. Clear Skies - Kurt
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