Author Topic: Monday 1 April 2013 - Looking for the Kaguya impact  (Read 3415 times)

jules

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Monday 1 April 2013 - Looking for the Kaguya impact
« on: April 01, 2013, 11:21:58 am »

Kaguya - NASA

Forum regular JJ went hunting for the Japanese lunar explorer Kaguya impact site. Kaguya (or SELENE: SELenological and ENgineering Explorer) was launched 14 September 2007. Once in lunar orbit Kaguya released two smaller satellites into separate elliptical polar orbits: Okina (a relay satellite for communications) and Ouna (a Very Long Baseline Interferometry (VLBI) radio source satellite for supporting radio measurements). As well as its 2 sub-satellites Kaguya carried 13 scientific instruments including a lunar Magnetometer,  a Gamma ray spectrometer, a Lunar Radar Sounder and an Earth-looking Upper Atmosphere and Plasma Imager. the mission lasted 18 months after which Kayuya was sent into a series of lunar orbits prior to a controlled impact on 10 June 2009. The impact site was conveniently in darkness at the time allowing the impact flash to be seen from Earth. Okina impacted on the far side on February 12 2009. Ouna is still in orbit.

The Kaguya mission amongst other things has improved lunar global topography maps (also used by Google to make Google Moon 3D), a detailed gravity map of the far side, and the first optical observation of the permanently shadowed interior of south pole Shackleton crater.

The Kaguya impact coordinates are well documented but we couldn't recall seeing a high resolution view of the impact site from LRO. What JJ was looking for was a small fresh impact which would have exposed some fresh lunar regolith leaving a white scar with a blackened centre where debris may remain.

The Kaguya website gives the impact coordinates as E80.4, S65.5. Here's the location:

http://www.kaguya.jaxa.jp

This indicates an impact site on the wall of an unnamed crater near crater Gill. Part of crater Gill is top left of this image provided by ESA:


http://sci.esa.int

Using the ACT-REACT Quick Map tool JJ located the unnamed crater.



And found a likely impact site on the rim of a smaller crater within the unnamed crater.



And finally - a potential impact site with a centre geodetic diameter of 23m:




We think it's definitely a contender.



JJ

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Re: Monday 1 April 2013 - Looking for the Kaguya impact
« Reply #1 on: April 01, 2013, 01:40:07 pm »
Thank you Jules, nicely written.

jules

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Re: Monday 1 April 2013 - Looking for the Kaguya impact
« Reply #2 on: April 01, 2013, 01:58:03 pm »
 :) Nicely found!

kodemunkey

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Re: Monday 1 April 2013 - Looking for the Kaguya impact
« Reply #3 on: April 01, 2013, 02:26:33 pm »
Have Ebb and Flow been located yet?


JJ

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Re: Monday 1 April 2013 - Looking for the Kaguya impact
« Reply #5 on: April 03, 2013, 06:59:26 am »
[/img]I found some more information regarding Kayuga and it's final flight path here
last few minutes locations



flight path




more orthographic views



This crater is actually in the wall of the larger crater and Kayuga slammed into the wall or rim of this smaller crater.






Another site I found gives more detailed information regarding viewing the flash located here and a section states "Evidently the Kaguya engineers and scientists expect the spacecraft to hit the north inner wall of this unnamed crater after it skims over the south rim. .... If the impact point is too far down inside the bowl of the crater, its west rim may well block the flash point from view." highlighting mine


This shows the craters bowl shape and the south rim which is lower.



This image shows the distance from the small crater to rim is about 5 km or 3.1 mi.



This image shows the approximate location of the impact crater ~5 mi down the wall face and the approximate distance to the south rim is somewhere around 17mi.



This image shows the topology and possible flight angle to clear ridges while traveling about 136 mi, I think if the graph wasn't so compressed the angle would appear much shallower over the long distance.




jules

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Re: Monday 1 April 2013 - Looking for the Kaguya impact
« Reply #6 on: April 03, 2013, 09:42:01 am »
Good work JJ. Great stuff. I think you nailed it! Those final images are very useful.
« Last Edit: April 03, 2013, 09:44:23 am by jules »