by neufer » Fri Oct 09, 2009 3:17 am
Orca wrote:neufer wrote:
There is no air to hold it up so it will probably be 5 minutes at most...as Nick Cabeo could tell you:
Yeah, I thought about that not long after I posted. In my head I was thinking of of the
comet impactor...where there wouldn't be enough gravity to hold on to the ejecta. I don't suppose this impactor will have enough mass to create a large enough explosion so that the material doesn't all return to the surface.
It's hard to imagine that the particles could have any greater velocity than
the incoming satellites themselves and hence could not have escape velocity.
Note the ~800m long rays below would correspond to
200m high parabolic trajectories lasting only about half a minute.
Now gases should go much higher but it is possible that Cabeus crater
is too deep for anything much to be observed directly from earth.
http://www.planetary.org/blog/article/00002149/ wrote:
LROC nabs image of the Apollo 14 S-IVB impact site
By Emily Lakdawalla Oct. 8, 2009
<<As a reminder that we've been crashing stuff into the Moon for decades, the Lunar Reconnaissance Orbiter Camera (LROC) team released today a photo of the crater made by the spent upper stage of the Saturn rocket that lofted the Apollo 14 mission to the Moon. It was intentionally crashed on Feburary 4, 1971 in part to remove it from orbit and in part to provide a "boom" of known time, location, and force to be recorded by the seismometer left behind from the Apollo 12 mission.
The dry weight of the S-IVB (which had expended nearly all of its fuel) was about 14,000 kilograms, 7 times heavier than the Centaur that will be smashing into the Moon tomorrow as part of the LCROSS mission. The crater that the S-IVB left behind is fairly small but it did produce a spectacular (if dainty at only 1.5 kilometers across) set of rays, which were intriguingly light in some places and dark in others.>>
Impact site of the Apollo 14 S-IVB from LROC
![Image](http://www.planetary.org/image/M107049825RE_crop.jpg)
On February 4, 1971, the spent upper stage of the Apollo 14 launch vehicle was intentionally crashed into the Moon, leaving behind a small crater with a pretty set of rays. The Lunar Reconnaissance Orbiter camera imaged it on September 8, 2009 under high sun conditions, emphasizing the differently shaded rays emanating from the crater.>>
[quote="Orca"][quote="neufer"]
There is no air to hold it up so it will probably be 5 minutes at most...as Nick Cabeo could tell you:
[/quote]
Yeah, I thought about that not long after I posted. In my head I was thinking of of the [url=http://www.nasa.gov/mission_pages/deepimpact/main/index.html]comet impactor[/url]...where there wouldn't be enough gravity to hold on to the ejecta. I don't suppose this impactor will have enough mass to create a large enough explosion so that the material doesn't all return to the surface.[/quote]
It's hard to imagine that the particles could have any greater velocity than
the incoming satellites themselves and hence could not have escape velocity.
Note the ~800m long rays below would correspond to
200m high parabolic trajectories lasting only about half a minute.
Now gases should go much higher but it is possible that Cabeus crater
is too deep for anything much to be observed directly from earth.
[quote=" http://www.planetary.org/blog/article/00002149/"]
LROC nabs image of the Apollo 14 S-IVB impact site
By Emily Lakdawalla Oct. 8, 2009
<<As a reminder that we've been crashing stuff into the Moon for decades, the Lunar Reconnaissance Orbiter Camera (LROC) team released today a photo of the crater made by the spent upper stage of the Saturn rocket that lofted the Apollo 14 mission to the Moon. It was intentionally crashed on Feburary 4, 1971 in part to remove it from orbit and in part to provide a "boom" of known time, location, and force to be recorded by the seismometer left behind from the Apollo 12 mission. [b]The dry weight of the S-IVB (which had expended nearly all of its fuel) was about 14,000 kilograms, 7 times heavier than the Centaur that will be smashing into the Moon tomorrow as part of the LCROSS mission.[/b] The crater that the S-IVB left behind is fairly small but it did produce a spectacular (if dainty at only 1.5 kilometers across) set of rays, which were intriguingly light in some places and dark in others.>>
[size=125][b]Impact site of the Apollo 14 S-IVB from LROC[/b][/size]
[img]http://www.planetary.org/image/M107049825RE_crop.jpg[/img]
On February 4, 1971, the spent upper stage of the Apollo 14 launch vehicle was intentionally crashed into the Moon, leaving behind a small crater with a pretty set of rays. The Lunar Reconnaissance Orbiter camera imaged it on September 8, 2009 under high sun conditions, emphasizing the differently shaded rays emanating from the crater.>>[/quote]