Structural disturbances of the lunar surface caused by spacecraft

• Published in: Solar system research Vol. 46; no. 2; pp. 108 - 118
• Main Authors: Kaydash, V. G., Shkuratov, Yu. G.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-04-2012; Springer Nature B.V
• Subjects: Astronomy; Astrophysics and Astroparticles; Astrophysics and Cosmology; Lunar eclipses; Observations and Techniques; Physics; Physics and Astronomy; Planetology; Spacecraft; Solar System Research; Phase Ratio; Lunar Surface; Impact Crater; Landing Site
• ISSN: 0038-0946; 1608-3423
• DOI: 10.1134/S0038094612020050

From the lunar surface survey performed with a narrow-angle camera of the Lunar Reconnaissance Orbiter (LRO) spacecraft, the distributions of the phase ratios of the
Apollo 11
and
12
landing sites and the
Ranger 9
impact site were mapped. In the acquired images, the traces of the structural disturbances of the lunar regolith layer caused by the jet flows are seen. In the
Ranger 9
impact site, one can see the crater of about 15 m across with a ray system, which is hardly noticeable in the brightness picture, but has a high contract in the phase ratio picture. The character of the photometric anomaly of the rays of this crater shows that they are formed by the ejected stones composing the rugged relief, which induces a strong shadow effect. At the same time, the influence of jet flows from the rocket engines smooths the relief and leads to the photometric anomaly of the opposite sign. The estimate of the maturity degree of the lunar regolith in the
Apollo 11
and
12
landing sites obtained from the SELENE spectral survey suggests that the depth of the influence of the rocket engines on the soil is small, and the surface of the impact crater formed by the
Ranger 9
spacecraft contains a large amount of the immature soil.