Archive for the lcross Category

The LCROSS brew

Posted in lcross, moon, usa on October 30, 2010 by moonmapper

The LCROSS probe has been featured on this blog before, but now the new goodies have been released, in form of five papers in the Science journal of Oct. 22.

We now know the content of volatiles (and other elements) in the soil at the LCROSS impact site. My visualizations below.

(click the image to get a fullsize view, or  here for an interactive visualization)

(click the image to get a fullsize view, or  here for an interactive visualization)

(click the image to get a fullsize view, or  here for an interactive visualization)

Key to symbols:

  • LTV – Low Temperature Volatiles (<600K)
  • HTV – High Temperature Volatiles
  • CON – early condensate
  • MET – metal
  • SIL – Silicate

Compiled from:

  • Colaprete et.al., “Detection of water in the LCROSS ejecta plume”, Science 330 (2010)
  • Gladstone et.al., “LRO-LAMP Observations of the LCROSS impact plume”, Science 330 (2010)

Notes:

  1. Gladstone et. al. give H2 content of 1.4% as measured by LRO. This omitted from the dataset, as this hydrogen is most likely already included in the organic compounds detected by LCROSS (as noted by Colaprete et.al.).
  2. Colaprete et. al. give the H2O content as 5.6+/-2.9% and give the content of other organics as percentage of water mass. To get absolute ppm, I have used the 5.6% figure.
  3. For some molecules, the given value is the upper limit.
  4. Note the difference between Co (cobalt) and CO (carbon monoxide).
  5. The published numbers add up to 34.73% of soil content. The remainder is unaccounted for and has been omitted from the visualizations for clarity.
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LCROSS impact site

Posted in kaguya, lcross, map, moon, usa on October 3, 2010 by moonmapper

On October 9th, 2009 the LCROSS spacecraft has been intentionally crashed inside the Cabeus crater in an attempt to verify presence of water ice. The mission proved successful and water molecules have been observed in the impact ejecta.

The mission actually involved two impacts. The first one, by a spent Centaur upper stage used to boost LCROSS to the Moon; the second one by the LCROSS shepherding spacecraft (SSC) itself, four minutes later. The SSC followed the Centaur on its way to annihilation, flying through the plume raised by the rocket’s impact and analyzing its composition. The concept has been neatly explained in this video:

This is the topography of the impact site (my render from Kaguya LALT data, click to get the high resolution PDF).

For comparison, below is a map of the impact site made available by NASA (from this PowerPoint presentation).

A NASA map of the impact site, from the LRO LOLA altimeter