LRO finds Apollo 16 booster impact site

[smartcooky]

http://scitechdaily.com/lunar-reconnaissance-orbiter-reveals-apollo-16-booster-rocket-impact-site/

[bknight]

Doesn't the moon have somewhat similar acoustic characteristics as the Earth's.  It seems like a triangular location using all the seismic monitors from the other missions could have at least narrowed the search area.

[smartcooky]

Doesn't the moon have somewhat similar acoustic characteristics as the Earth's.  It seems like a triangular location using all the seismic monitors from the other missions could have at least narrowed the search area.

Even if it did, I'm not sure you could pinpoint the location of a surface of a minor seismic event within a few km unless the sensors were really close. To get accurate locations of seismic epicentres on Earth requires accurate knowledge of the Earth's sub-surface structure (different types of structures have different transmission characteristics) . I'm not sure we have that for the Moon yet.

30km accuracy rather than 7km means that the search area is about 18 times larger. When you are already looking for a needle in a haystack, another 17 haystacks is  not going to make things easy.

[bknight]

From the data acquired during the previous impacts time versus distance should have been calculable.
Remember that the Navy's sonar arrays were able to proximate the locations of two submarine accidents several thousand miles away, yes I know that water and the Lunar surface are far different.
A13 S-IVB impact was recorded by A12 at a distance seismic station 135 km.  The rest were recorded
http://news.discovery.com/space/history-of-space/what-happened-to-all-the-saturn-v-rocket-stages-140116.htm.
Seems like simple analysis would have give a more precise location, but I'm speculating.

[Zakalwe]

From the data acquired during the previous impacts time versus distance should have been calculable.
Remember that the Navy's sonar arrays were able to proximate the locations of two submarine accidents several thousand miles away, yes I know that water and the Lunar surface are far different.
A13 S-IVB impact was recorded by A12 at a distance seismic station 135 km.  The rest were recorded
http://news.discovery.com/space/history-of-space/what-happened-to-all-the-saturn-v-rocket-stages-140116.htm.

To be fair, the article did say that the locations were "poorly known". That might be within the tolerance of the method used?

Seems like simple analysis would have give a more precise location, but I'm speculating.

The fact that some of the best brains on the planet were unable to precisely locate the impact site probably means that your conclusion is incorrect. Don't you think that they would have carried out simple analysis first?  https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect

[bknight]

The fact that some of the best brains on the planet were unable to precisely locate the impact site probably means that your conclusion is incorrect. Don't you think that they would have carried out simple analysis first?  https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect

To be fair, you're assuming that they did just that.  I don't know if they did or not.

[smartcooky]

LRO was launched in June 2009. By October that year, it had found the Apollo 14 booster impact site, and the Apollo 13 impact site was found and photographed by March 2010. A15 and A17 were found by the end of 2011. It took another four years to find this last one.

Here is probably a good part of the reason why it has taken so long.

http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_impact.html

*A malfunction resulted in premature loss of tracking data for the Apollo 16 SIVB.
Time, location, and impact energy are estimates based on interpretation of seismic data.
Uncertainty in the Apollo 16 impact time is about 4 seconds.
Uncertainty in the Apollo 16 impact location is about 0.7 deg. latitude, 0.3 deg. longitude.
(The impact location estimated based on tracking prior to signal loss is 2.24 N, 24.49 W)

It appears their estimated location was not far out

Apollo 16’s S-IVB stage is on Mare Insularum, about 160 miles southwest of Copernicus Crater (more precisely: 1.921 degrees north, 335.377 degrees east, minus 1,104 meters elevation).

By my calculation, they were out by 0.26° in longitude and 0.319° latitude.

[bknight]

LRO was launched in June 2009. By October that year, it had found the Apollo 14 booster impact site, and the Apollo 13 impact site was found and photographed by March 2010. A15 and A17 were found by the end of 2011. It took another four years to find this last one.

Here is probably a good part of the reason why it has taken so long.

http://nssdc.gsfc.nasa.gov/planetary/lunar/apollo_impact.html

*A malfunction resulted in premature loss of tracking data for the Apollo 16 SIVB.
Time, location, and impact energy are estimates based on interpretation of seismic data.
Uncertainty in the Apollo 16 impact time is about 4 seconds.
Uncertainty in the Apollo 16 impact location is about 0.7 deg. latitude, 0.3 deg. longitude.
(The impact location estimated based on tracking prior to signal loss is 2.24 N, 24.49 W)

It appears their estimated location was not far out

Apollo 16’s S-IVB stage is on Mare Insularum, about 160 miles southwest of Copernicus Crater (more precisely: 1.921 degrees north, 335.377 degrees east, minus 1,104 meters elevation).

By my calculation, they were out by 0.26° in longitude and 0.319° latitude.

Thanks, I stand corrected.

[ka9q]

That's correct, the S-band transponder on the Apollo 16 S-IVB was lost at 97,799 seconds for unknown reasons. The telemetry subcarrier was turned off much earlier in the flight but the carrier was left on for Doppler tracking and it should have stayed on until lunar impact.

This was several days before it reached the moon, so the impact point had to be projected from earlier tracking data only. That was less accurate than for other missions where the transponders worked until impact.

[onebigmonkey]

On the subject of impact craters, I spent some time looking for the Apollo 14 SIV-B impact site after reading that Apollo 16's Panoramic Camera had found it http://www.planetary.org/blogs/emily-lakdawalla/2009/2149.html

Turns out Chandrayaan also did a partial image of the impact crater:

[bknight]

On the subject of impact craters, I spent some time looking for the Apollo 14 SIV-B impact site after reading that Apollo 16's Panoramic Camera had found it http://www.planetary.org/blogs/emily-lakdawalla/2009/2149.html

Turns out Chandrayaan also did a partial image of the impact crater:

Towards the lower center or left?

[ka9q]

I've noticed that the artificial craters are most conspicuous in the noontime pictures when the natural craters become almost invisible. The artificial craters are very bright, but they all look much the same at lower sun angles. I wonder why this is so?

[bknight]

The more reflective surfaces of the metal versus the regolith, probably.

[onebigmonkey]

On the subject of impact craters, I spent some time looking for the Apollo 14 SIV-B impact site after reading that Apollo 16's Panoramic Camera had found it http://www.planetary.org/blogs/emily-lakdawalla/2009/2149.html

Turns out Chandrayaan also did a partial image of the impact crater:

Towards the lower center or left?

It's left of centre at the top - you can see the dark material spreading out, made more obvious where crater rims have shielded the existing surface from impact debris.

[bknight]

On the subject of impact craters, I spent some time looking for the Apollo 14 SIV-B impact site after reading that Apollo 16's Panoramic Camera had found it http://www.planetary.org/blogs/emily-lakdawalla/2009/2149.html

Turns out Chandrayaan also did a partial image of the impact crater:

Towards the lower center or left?

It's left of centre at the top - you can see the dark material spreading out, made more obvious where crater rims have shielded the existing surface from impact debris.

I was way off as the lower two sites looked brighter than the upper ones.  I'm obviously general Lunar location challenged.