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Topic: Moon is more Metallic than Thought Before
Why in News?
- Using the Miniature Radio Frequency (Mini-RF) instrument on Lunar Reconnaissance Orbiter (LRO) spacecraft, the National Aeronautics and Space Administration (NASA) has revealed that the Moon's subsurface may contain vast amounts of iron and titanium than researchers thought before.
Hypothesis of Moon’s Origin
- Substantial evidence points to the Moon as the product of a collision between a Marssized protoplanet and young Earth, forming from the gravitational collapse of the remaining cloud of debris. The hypothesis is also backed by substantial evidence, such as the close resemblance between the Moon’s bulk chemical compositions with that of Earth.
- However, it is also known that Earth’s crust has lesser amounts of iron oxide than the Moon– a finding that scientists have been trying to explain. Now, the new discovery of even greater quantities of metal on the Moon makes their job even more difficult.
- In the bright plains of the Moon’s surface, called the lunar highlands, rocks contain smaller amounts of metal-bearing minerals relative to Earth. That finding might be explained if Earth had fully differentiated into a core, mantle and crust before the impact, leaving the Moon largely metal-poor. But turn to the Moon’s Maria — the large, darker plains — and the metal abundance becomes richer than that of many rocks on Earth.
- Using Mini-RF, the researchers sought to measure an electrical property within lunar soil piled on crater floors in the Moon’s northern hemisphere. This electrical property is known as the ‘dielectric constant’.
- ‘Dielectric constant’ is the ratio of the electric permeability of a material to the electric permeability of a vacuum. It could help locate ice lurking in the crater shadows. The team, however, noticed this property increasing with crater size.
- Discovery of this pattern opened a door to a new possibility. Because meteors that form larger craters also dig deeper into the Moon’s subsurface, the team reasoned that the increasing dielectric constant of the dust in larger craters could be the result of meteors excavating iron and titanium oxides that lie below the surface. Dielectric properties are directly linked to the concentration of these metal minerals.
About LRO Mission
- The Lunar Reconnaissance Orbiter (LRO) is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit.
- Its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies.
- The probe has made a 3-D map of the Moon's surface at 100-meter resolution and 98.2% coverage (excluding polar areas in deep shadow), including 0.5-meter resolution images of Apollo landing sites.
India on Moon
- Chandrayaan-1 was the first Indian lunar probe under Chandrayaan program. The mission included a lunar orbiter and an impactor
- Chandrayaan-2 is the second lunar exploration mission, it consists of a lunar orbiter, and also included the Vikram lander, and the Pragyan lunar rover, all of which were developed in India.
- India has announced plans for a third lunar mission in 2020 but that it "may spill over" to 2021.