KREEP material would have been pushed by the wave of heat generated at the impact zone, spreading beneath the crust and coming to rest on the nearside. This plume, the researchers say, would have carried elements in KREEP predominantly away from the impact - towards the nearside volcanic plains of the Moon. However, the team’s models show that a heat plume generated by an asteroid impact of the size that formed the SPA would severely alter the distribution of this material. Therefore, it should be dispersed on the top layer of the mantle, just below the crust, and evenly distributed. KREEP is believed to be one of the last fractions (components) of the lunar mantle to have solidified after the Moon formed. Researchers from Purdue University, the Lunar and Planetary Science Laboratory in Arizona, Stanford University, and NASA’s Jet Propulsion Laboratory also took part in the study. Alongside his team, he carried out a battery of computer simulations analyzing these movements, in order to understand how the event impacted the heat flows throughout the Moon’s interior and, ultimately, the distribution of KREEP materials throughout its body. Given this link between certain chemical elements and thermal energy - a link that holds true on Earth as well - Jones set out to understand how a significant asteroid impact would shift the internal chemistry of the Moon. Among the minerals that make up the name, KREEP also includes elements like thorium which are produced through atomic decay, a process that releases heat. PKT - with KREEP being short for potassium (K), rare earth elements (REE), phosphorus (P) - seems to be concentrated in and around Oceanus Procellarum, the largest of the nearside volcanic plains but is quite rare elsewhere on the Moon. Later missions would delve into the geochemical differences between these two faces as well, revealing that the nearside is defined by a chemical anomaly known as the Procellarum KREEP terrane (PKT). Apollo program finally put the Moon within our reach, giving humanity our first glance at the far side of the Moon. The difference between the two became apparent after the Soviet Luna missions and the U.S. On the other hand, the far side is littered with craters but lacks such lava flows almost entirely.Įxactly why the two are so different has long been an interesting but puzzling question. A vast surface of the nearside is dominated by the lunar mare, the dark-colored traces of ancient volcanism. The two faces of the Moon, one locked towards Earth, the other looking perpetually away, are two very different places. We expect that this contributed to the mantle melting that produced the lava flows we see on the surface.” “What we show is that under any plausible conditions at the time that SPA formed, it ends up concentrating heat-producing elements on the nearside. “The question is how that heat affects the Moon’s interior dynamics.” candidate at Brown University and the study’s lead author. They collected hundreds of pounds of lunar soil and rock samples, conducted experiments and installed equipment for follow-up measurements.“We know that big impacts like the one that formed the SPA would create a lot of heat,” said Matt Jones, a Ph.D. On July 20, 1969, NASA astronauts Neil Armstrong and Buzz Aldrin were the first people to set foot on the dusty surface of the Moon. The Moon is the only other planetary body that humans have visited. For example, NASA's Lunar Reconnaissance Orbiter has been circling the Moon and sending back measurements since 2009.
Today, we study the Moon using telescopes and spacecraft. Later, people used their observations of the Moon to create calendars. How do we study the Moon?Įven thousands of years ago, humans drew pictures to track the changes of the Moon. The impact sent chunks of Earth and the impactor into space that were pulled together by gravity, creating the Moon. Scientists believe that the Moon formed early in the solar system’s history after Earth and an object about the size of Mars smashed into each other. Credit: NASA/Goddard Space Flight Center/Arizona State University How did the Moon form? This image is based on data from NASA’s Lunar Reconnaissance Orbiter spacecraft. Notice how few dark areas the far side has. The "far side" of the Moon looks very different than the near side (see the first photo in this article).
0 kommentar(er)
