Tag Archive | fractures

Deep Seated Fractures – the hunt for Transient Lunar Phenomena

Deep Seated Fractures

Deep Seated Fractures

Transient Lunar Phenomena (TLP) are one of the projects we are working on in the Moon Zoo forum as a direct result of a challenge set by Moon Zoo team member Anthony Cook – see forum thread: Moon Zoo Challenge.
In Anthony’s Looking For Change blog he says that we should be looking out for any interesting surface features that may have been freshly disturbed or contain a vent from which outgassing has occurred. “TLP” projects have been set up in the forum for each of the features mentioned, except for Deep Seated Fractures and another feature, “Atmospheric” phenomena (which was not mentioned by Anthony).

Deep seated fractures can be found on some images from LROC but “Atmospheric” phenomena will probably not be found. Some images taken during the Apollo project had fuzziness along the horizon when it was expected that the horizon would be sharp-edged. This may have been caused by dust particles suspended above the lunar surface by electrostatic charging.

Deep Seated Fractures

The one feature which Anthony mentioned and which is not covered in the other TLP Project threads is deep seated fractures and he uses an example from the floor of Tycho crater:

Tycho Crater floor, from LROC image M114031031LE

One of the Moon Zoo users, ElisabethB (Els), found something similar near Proclus crater:

ID: AMZ400381n
Latitude: 16.4221°
Longitude: 46.4991°
Sun Angle: -76.23°
Scale: 0.50 meters / pixel
Zoom Level: 3

“Atmospheric” Phenomena

Apollo 17 astronauts saw and sketched what they called “bands”, “streamers” and “twilight rays” which were visible just before lunar sunset or sunrise. These rays were also seen by astronauts on the Apollo 8, 10 and 15 missions.

from Nasa Media Library

On the side of the Moon in daylight, the solar radiation knocks electrons out of atoms and molecules in the regolith. A positive charge builds up which is sufficient to loft particles 1 micron and smaller in size above the surface. These particles can go up more than a kilometre.

The Moon seems to have a tenuous atmosphere of moving dust particles. We use the word ‘fountain’ to evoke the idea of a drinking fountain: the arc of water coming out of the spout looks static, but we know the water molecules are in motion. In the same way, individual bits of moondust are constantly leaping up from and falling back to the Moon’s surface, giving rise to a “dust atmosphere” that looks static but is composed of dust particles in constant motion.
[quote byTimothy J. Stubbs, of the Laboratory for Extraterrestrial Physics at NASA’s Goddard Space Flight Center]

It is believed that the dust on the night side of the Moon is negatively charged due to electrons from the solar wind flowing around the Moon onto the night side. So at the Moon’s terminator between the positively charged dust of the daylight side and the negatively charged dust of the night side, there could be flows of dust which may resemble auroras.

The four links below from NASA discuss various aspects of this phenomena:

Moon Fountains

Moon Dust in the Wind

Moon Storms

Lunar Transient Phenomena