Initial List of Impact Dates and Times

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May 26, 2009, 11:32:28 PM5/26/09
to LCROSS_Observation
Tony Colaprete and the LCROSS Science Team are releasing their initial
list of impact dates and times corresponding to launch opportunities
in the June 17-21 window.

A launch on June 17 results in an impact on October 8 at 10:30 UT.
A launch on June 18 results in an impact on October 9 at 11:30 UT.
A launch on June 19 results in an impact on October 10 at 12:30 UT.
A launch on June 21 (June 20 EDT) results in an impact on October 11
at 13:30 UT.

These times are preliminary and could be subject to change. We’ll post
any updates on this site.

Looks like best visibility for the widest portion of North America
corresponds to the June 17 launch. Let's all hope for good weather at
the cape that afternoon!

Brian Day

Derek C Breit

May 26, 2009, 11:55:52 PM5/26/09


Actually.. Let's hope they change their plans completely.. These conditions
leave little hope that amateurs can capture the plume on video.. Of course
we will try anyway, but this is rather depressing news to me..



May 27, 2009, 2:30:53 AM5/27/09
to LCROSS_Observation

My Friends,

This list of dates and times of the impact is not conducive to
observation of the impact in Brazil.

In my Astronomical Station, the first time proposed for the impact,
all of which would be the least bad, happen in broad daylight, at
07:30 hours of the morning - local time. The Moon is 13 degrees above
the western horizon and the sun is now visible to 33 degrees above the
eastern horizon.

Are bad news for me!

I am also in the expectancy of a better time for the impact.


Valmir Martins de Morais

Estação Astronômica PieGise
Juazeiro do Norte, Ceará - Brasil
Lunar Section of the Rede de Astronomia Observacional - REA/Brasil

Jim Mosher

May 27, 2009, 9:55:30 PM5/27/09
to LCROSS_Observation
Valmir -

Yes, despite earlier mentions of a possible professional impact
observing campaign at observatories in Chile, it appears the impact is
no longer planned for a time favorable to South America.

Observers elsewhere in the world may be interested in the webpage at:

A series of four Earth-globes near the top of the page (click on them
to see larger versions) should show at a glance what parts of the
Earth the Moon will be visible from at the times announced in this
thread. The Sun will be up in areas to the right of the red
terminator line (which, as you note, includes Brazil).

At the bottom of the page there is a corresponding series of four
simulations approximating what the Moon's south pole will look like
for those lucky enough to be able to view it at those hours. The Sun
will be near its maximum southerly latitude on the Moon in October, so
the lighting of the south polar features is about as strong as it
gets. The libration will change significantly from night to night.

-- Jim
> > Hide quoted text -
> - Show quoted text -

Arnold Ashcraft

May 28, 2009, 12:40:16 PM5/28/09
It looks like that the east coast observers are also out of luck
unless NASA goes for the earliest of the mentioned impact times. We
can still provide some support to the operation by obtaining early
images of the impact area the evening of the impact and making
annotated copies available online for those in a position to observe
the event to use as pointing charts. If it is clear in New Jersey on
the night of impact, I will get busy imaging the area as soon as it
is dark enough to do so and will immediately upload my images to the
LCROSS group files.
Do you have any feedback from the professionals that our imaging has
helped them with pointing the instrument on Mauna Kea?

Jim Mosher

May 28, 2009, 1:00:59 PM5/28/09
On Thu, May 28, 2009 at 9:40 AM, Arnold Ashcraft <> wrote:
> Do you have any feedback from the professionals that our imaging has
> helped them with pointing the instrument on Mauna Kea?

No. Dr. Wooden requested archival images before some of her test runs
started, but I have never heard what she attempted in those runs,
whether they were successful, or if our efforts helped.

The last I heard was that her web browser was unable to display the
images I posted on pages such as:

so I sent copies to her as e-mail attachments. I don't know if she
has been able to see the images we post here.

-- Jim

May 28, 2009, 2:17:40 PM5/28/09
to LCROSS_Observation
The impact change date starts to favor the northern hemisphere and
Pacific coasts in terms of lunar altitude as well as by time:

Compare Figures 8

and Figure 8

in group page

Clear Skies, Kurt


May 28, 2009, 6:21:28 PM5/28/09
to LCROSS_Observation
I fully agree with Cliff and I commend the initiative of Jim Mosher
for rapid collection and provision of data for the days scheduled for
the impacto.

The Jim made a new great job, available to all, and virtually
instantaneous information necessary for visibility of the impact to
their places of observation.

As Cliff said, If we can not observe the impact could very well work,
giving our contribution, providing data and images, to those who can
see the impact.

Congratulations! You are examples of how astronomy is based on the
collaboration of all, as we say here in Brazil!


Valmir M. de Morais.

On 28 maio, 15:17, "" <> wrote:
> The impact change date starts to favor the northern hemisphere and
> Pacific coasts in terms of lunar altitude as well as by time:
> Compare Figures 8
> and Figure 8
> in group page

jim phillips

May 28, 2009, 7:38:49 PM5/28/09
Things seem to change every month but I will be ready to go with images before during and after impact if at all possible.
> Date: Thu, 28 May 2009 12:40:16 -0400
> From:
> Subject: [LCROSS_OBS: 692] Re: Initial List of Impact Dates and Times
> To:

May 30, 2009, 7:15:53 PM5/30/09
to LCROSS_Observation
5/25/2009 LCROSS Facebook page entry on south polar impact date:

"LCROSS Lunar Impactor Mission at 7:55am May 25
We have not announced the impact time since it is heavily dependent on
launch date and also the in-flight orbit corrections the team must
execute. For a June 17-21 launch window, we know the impact will be at
the south pole. The "exact" location (which crater) will be determined
at impact minus 30 days. Updates to the impact time will be
updated ... Read Morethen as well. It is a big trajectory calculation
that moves the exact location/time around. For a nominal June 17th
launch (for one window of several that day), impact is Oct 8th, around
10:30 UTC (ish). That's about 3:30 AM PDT. The timing is optimized to
get the moon high over Hawaii. If we launch from another date or
another window within that June 17th the impact date and time of
impact changes. We are excited that these potential Oct 8-11th impact
dates (told you there was a range!) provide a visible moon to most of
the western continental US to observe the impact.
Stay tuned!
LCROSS Facebook team."

5/21/2009 NASA LRO-LCROSS Press Release on the May 21 News conference
re: June 17 launch date

Please note on the main NASA LCROSS page - an active launch countdown
timer is now present.

- Clear Skies - Kurt

May 30, 2009, 7:19:51 PM5/30/09
to LCROSS_Observation
Url on the NASA LCROSS Facebook quotation is:

> 5/25/2009 LCROSS Facebook page entry on south polar impact date:
. . . .

May 30, 2009, 7:25:30 PM5/30/09
to LCROSS_Observation

This is to request that this newsgroup be linked back into the NASA
LCROSS Observation Campaign webpage at:

The link to this newsgroup was edited out three or four months ago.

Sincerely, - Kurt

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