Essay 3 - The Earth\'s Moon: An Ancient World Prototype The Moon is often referr

Question

Essay 3 - The Earth's Moon: An Ancient World Prototype

The Moon is often referred to as the "Earth's Attic". Much like how your grandparent's attic likely contains old photos, trophies, antiques, and other memorabilia, all documenting in some way the past history of your family, the Moon stores the past history for the Earth and the rest of the terrestrial worlds of the inner Solar System. (1) Describe in detail one piece of that history that is retained on the surface of the Moon but has been lost from the surfaces of the terrestrial planets. (2) Your response should include why or how that evidence is retained on the Moon and why or how it was lost (erased?) from the surface(s) of the other world(s).

Explanation / Answer

The occurrence of both lunar and Martian meteorites on the Earth specified that the transport of planetary material is regular in the solar system. Dynamic hydrologic or tectonic cycles, past or present, avoid the planetary bodies from working as long-term repositories of this material. But the Moon is an important exemption, however. Moon is located within the inner solar system and also the Moon has hypothetically collected material from all of the terrestrial planets since its formation. Because of the lacking of an atmosphere and extensive, long-lasting volcanism, the Moon has potentially conserved meteorites from Mercury through the asteroid belt. But the lack of an atmosphere prevents a flexible landing on the lunar surface, its low gravity causes particles with small velocities with respect to the Moon will experience comparatively low impact velocities. In addition, contrasting to other terrestrial planets, Martian, Venusian and Terran meteorites, blasted off their respective planets during the Late Heavy Bombardment, should still survive on the surface of the Moon. Such meteorites preserved remains of these planets that are not available anywhere in the Solar System. In particular, Terran meteorites on the Moon may provide a valuable geological record for ancient Earth, corresponding to the period for which the initial evidence for life exists.

The Moon may protect material not only from Earth, but also from Venus and the asteroid belt. The only possible record of Venus’s early surface geology, is probably on the Moon. Correspondingly, a record of the type, characteristics and origins of the heavy bombardment impactors themselves may be available on the Moon. Such a record would explain not only the geological history of Earth, but also its chemical and biological history especially since these impactors were major sources of biotic ancestors on early Earth.

Mars is presently the focus of attention for early symbols of life outside Earth. Ironi, the Moon may be the superior place to search for the residues of both early Martian and early Terran life. Most appreciably, the Moon has lack of water capable of carrying contaminants into the interior of rocks through cracks. While gardening from micrometeorites is less severe on the surface of Mars, the deeply buried regolith on the Moon provides some protection. Finally, the Moon is also an ideal test bed for targeted sample return. For all these reasons, we determined the probability that early remains of Earth, Mars, and Venus have been conserved on the Moon in large enough concentrations to inspire a search mission.

Large impacts on the Earth generate ejecta with launch velocities near to or beyond the escape velocity. This material cooperates with the Moon in a number of ways. Ejecta with speeds near the escape velocity eventually falls back to the Earth, gets cleaned up by the Moon, or attain a stable orbit around the Earth. Ejecta with velocities exceeding the escape velocity either hit the Moon while escaping the Earth-Moon system, or get a stable solar orbit. We explore the velocity distribution of the ejecta from low speeds that just allow particles to reach the lunar orbit, up to speeds exceeding the escape velocity.

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.