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View Full Version : Can we see Apollo SIVB impact craters from earth telescopes?



John Kierein
2003-Aug-01, 12:01 PM
Some of them came in at low grazing angles and may have left a long scar.
http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_tables.html

kucharek
2003-Aug-01, 12:18 PM
Have a look at the end of http://www.hq.nasa.gov/office/pao/History/SP-362/ch5.2.htm

The A14 S-IVB produced a 40m crater. From plenty of threads here we know, that Hubble can resolve to some 100m.

So, I'd say these craters are not visible from Earth.

John Kierein
2003-Aug-01, 12:32 PM
But at only a 3.5 degree angle of incidence it might've kicked up a long streak of underlying stuff that could be contrasty to the rest of the surface. I'd think it might show up with some good image processing maybe using ENVI.
http://www.rsinc.com/envi/index.cfm

kucharek
2003-Aug-01, 12:38 PM
I don't know if the density and velocity of the impacting objects were above the level where it leaves circular craters independent of impact angle.

snowcelt
2003-Aug-01, 12:50 PM
John Kierein. Sir. You must see that the probability of an object stricking the surface of Luna at 3.5^ to be somewhat extrodinary, eh? The spelling handicap notwithstanding: Why would the LM act with such a **** poor orbit?

John Kierein
2003-Aug-01, 12:52 PM
AS16-5444 (P) from your link shows a very long white line extending to the NE from the impact crater (assuming N is to the top of the picture). This may be a coincidence, or possibly the SIVB ricocheted off in that direction and bounced and rolled a long way in the low lunar gravity.

John Kierein
2003-Aug-01, 12:56 PM
The tables I posted give the velocity, energy and impact angles of all the Apollo SIVB stages. The LM had long separated from the SIVB before the impact and had its own thrusters changing its trajectory; so the LM didn't land at such a grazing incidence. You'll note that 4 of the SIVBs hit at very low angles; below 5 degrees.
The SIVB quit firing shortly after leaving the earth. The LM separated shortly after that and moved safely away from the big SIVB. They both continued to coast to the moon. The LM then fired thrusters went into lunar orbit and the SIVB just crashed.

Gmann
2003-Aug-01, 12:57 PM
It really doesn't matter. the moon hoaxers have their "minds" set on the assumption that we didn't go at all, and will find any explanation, however ludicrious, to support their theory. I remember a time a few years back where Art Bell interviewed one of the people who produced the FOX show, and on the other line had his buddy Richard C.Hoagland, and "Hoaxland" ripped him to shreds (imagine hoagland debunking woo woo), it was an ugly scene, but Hoagland proved his point and made this producer look like an idiot. It goes back to Chicken Little, tell him that the sky is not falling, and he will insist that the Earth is rising. ](*,)

John Kierein
2003-Aug-01, 01:04 PM
I don't care about the moon hoaxers. I just like to know stuff like this.

AGN Fuel
2003-Aug-01, 01:11 PM
Some of them came in at low grazing angles and may have left a long scar.
http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_tables.html

The table actually seems to show that the S-IVBs struck at quite high angles, not at all grazing. The most acute angle according to the table is A17 S-IVB at 55 degrees to the horizontal. The LMs all had very acute impact angles, but lower impact velocities & much less mass. This is reflected in the considerably lower impact energies quoted.

John Kierein
2003-Aug-01, 01:21 PM
I obviously can't read a table. I followed the wrong line and was confusing the SIVB with the LM. The LMs come in from lunar orbit and are more nearly horizontal. The SIVBs came in directly.
Still the white line extending from the crater is intriguing. Even at 69 degrees a part of it might have bounced and skidded along. Perhaps the oxygen tank came off and went a different direction. I wonder if the line was there before the impact. It goes off to the edge of the image, distance of more than 4 kilometers.

kucharek
2003-Aug-01, 01:23 PM
Of course, that's how it must have been. The S-IVBs simply dropped down onto the moon, while the LMs were in orbit and just decelerated enough so their trajectories intersected the surface.

ABTN (http://history.nasa.gov/SP-4029/SP-4029.htm) also lists calculated crater diameters for the LM impacts (http://history.nasa.gov/SP-4029/Apollo_18-29_LM_Lunar_Impact.htm) and calculated and measured crater diameters for the S-IVB impacts (http://history.nasa.gov/SP-4029/Apollo_18-26_S-IVB_Lunar_Impact.htm)

John Kierein
2003-Aug-01, 01:34 PM
Interesting calculations. The crater diameter for the Apollo 14 was very slightly smaller than predicted while the Apollo 13 one was "right on". So maybe my specualtion about the white line being an oxygen tank could account for the difference.

I worked way too long on Skylab. The SIVB was used as the Skylab workshop module. The crew lived in the big hydrogen tank portion and used the spherical oxygen tank for a waste dump like a landfill. Even thought the oxygen tank was smaller than the hydrogen tank, it was plenty big enough to leave a good trail.

AGN Fuel
2003-Aug-01, 01:39 PM
I obviously can't read a table. I followed the wrong line and was confusing the SIVB with the LM. The LMs come in from lunar orbit and are more nearly horizontal. The SIVBs came in directly.
Still the white line extending from the crater is intriguing. Even at 69 degrees a part of it might have bounced and skidded along. Perhaps the oxygen tank came off and went a different direction. I wonder if the line was there before the impact. It goes off to the edge of the image, distance of more than 4 kilometers.

It's interesting, but I thnk it is coincidental. Striking at 69 degrees and travelling at over 2.5 km/second - that's a LOT of kinetic energy! :D I don't think there would be too much left to scrape up.

If a component had broken free at impact, and survived. at that angle of incidence I would expect it to 'bounce' rather than 'skid'. The white line appears pretty much continuous, which is inconsistent with that type of impact. It also seems to be extending for an awfully long way - difficult to establish scale, but if the impact crater is 40 metres, then that line extends several kilometres at least.

John Kierein
2003-Aug-01, 01:43 PM
The Apollo 14 SIVB weighed about 1200 lbs more than the Apollo 13. I presume this was residual fuel, mostly oxygen. If the oxygen tank came off nearly intact and ruptured it may have been venting as it went bouncing along. Cool.

kucharek
2003-Aug-01, 01:45 PM
I worked way too long on Skylab.
What was your job? The museum of natural history here in Karlsruhe has a nice collection of meteorites and beside, a good chunk of Skylab debris. Looks like the circular end piece of a cylindrical tank with rounded edges, maybe 1 foot in diameter.

John Kierein
2003-Aug-01, 01:47 PM
There's a scale at the bottom of the picture. It looks like the streak is about 4 kilometers long before it runs off the picture.

AGN Fuel
2003-Aug-01, 01:54 PM
ABTN (http://history.nasa.gov/SP-4029/SP-4029.htm)


Aaagghh!! Why...did...no-one...tell...me...about...this...site...before?! :evil:

I have been trawling through the ALSJ for the past week to try to find a range of information - everything that I was looking for is neatly set out in a *#&% table in this document! D'OH!!! #-o #-o #-o

John Kierein
2003-Aug-01, 01:56 PM
I do lots of fun stuff. I've worked on both manned and unmanned spacecraft since the days of Gemini. Mostly called systems engineering or experiment integration or other aerospace jargon stuff. Recently I've been helping different aerospace companies write proposals. Haven't lost one yet. I'm just finishing a job in Tucson.

Skylab had lots of tanks. I'd guess this could have been a piece of the furnace we used to grow crystals. It was pretty hefty and might have survived re-entry. There were other cylindrical tanks that carried water, but they were much bigger. These were lined up around the inside and the crew used to "jog" around them. Most of the other tankage was more spherical.

kucharek
2003-Aug-01, 02:06 PM
ABTN (http://history.nasa.gov/SP-4029/SP-4029.htm)


Aaagghh!! Why...did...no-one...tell...me...about...this...site...before?! :evil:

I have been trawling through the ALSJ for the past week to try to find a range of information - everything that I was looking for is neatly set out in a *#&% table in this document! D'OH!!! #-o #-o #-o

Maybe you should have asked... BTW, it was supported by the usual suspects (http://history.nasa.gov/SP-4029/Apollo_00d_Acknowledgements.htm) (though Rich did 99% of the work...)
And if you find information that would fit neatly into a table but is not yet in the ABTN, just drop Rich a note.

John Kierein
2003-Aug-01, 02:28 PM
Here's an outline of the Skylab stuff. The big tank at the bottom below the living quarters (which was the SIVB H2 tank) is the oxygen tank. There was an "airlock" between the two where the crew dumped their trash. This airlock was also pretty thick and might have survived, but it wasn't really cylindrical.
http://history.nasa.gov/SP-400/p3.htm

Here's an image of the materials processing facility that might have survived. It was not in the OWS but was in the module atop it, the MDA. There was a furnace inside it also. Lots of thick-walled parts and more cylindrical looking stuff.
http://images.jsc.nasa.gov/iams/images/pao/SL2/10076072.htm