Until then, geologists had only been able to glean relative ages of impact sites. With the Apollo samples in hand, they were able to directly determine the ages of the regions they sampled, then calculate an approximate age for unsampled basins. That work paved the way for better understanding of much more distant destinations as well.
By setting the age of impacts on the moon during Apollo 11 and subsequent missions, scientists have been able to estimate the age of craters in other parts of the solar system.
Mars, for example, should have received about the same number of impacts as Earth, allowing researchers to date its different landscapes using ages taken from the lunar landscape. Even Pluto's cratering estimates relied on measurements made from the moon's craters! Scientists analyzed lunar samples for organic material, past or present, and found none.
The only traces of non-biological organic material such as amino acids were faint and attributed to meteorites. Decades after the samples arrived on Earth, scientists also reanalyzed some Apollo moon rocks, including some from Apollo 11, and discovered trace amounts of water in those samples.
Researchers determined that the water was delivered to the lunar surface by comets or meteorites striking the surface. These samples have also taught scientists that the moon has a strong chemical similarity to rocks on Earth. Moreover, both are dramatically different from Martian and asteroid belt meteorites. This profile was one of the things that led Hartmann and his colleague Don Davis to propose in that the moon formed from debris blown off Earth after a cataclysmic impact early in Earth's lifetime.
Their theory remains the leading proposal for how the moon formed. One of the experiments Apollo astronauts left on the lunar surface was the Laser Ranging Retroreflector. Scientists can precisely measure the distance between Earth and its moon by lighting up the carefully tailored mirrors with laser beams aimed from large Earth-based telescopes. In addition to improving scientists' knowledge about the moon's orbit and rotation, the experiment also found that the moon is receding from the Earth at a rate of 1.
The Laser Ranging Retroreflector "is the only Apollo 11 experiment that is still operational, because it is just a set of mirrors designed to reflect laser pulses from Earth and does not require any power," Williams said. Apollo 11 was the first of several Apollo missions to deploy the Solar Wind Composition Experiment , an aluminum foil sheet deployed on a pole facing the sun.
The solar wind is the flood of charged particles streaming off the sun and across the solar system, shaping the environment of all the planets and moons. In order to better understand what particles are found in that solar wind, the astronauts unfurled the foil sheet, left it exposed to the sun for 77 minutes, then collected it and returned to Earth, where it could be chemically analyzed. Later Apollo crews did the same. One difference is that the Apollo 11 basalts contain much more of the element titanium than is usually found in basalts on Earth.
As a result, the mineral ilmenite is abundant in Apollo 11 basalts. Another titanium-bearing mineral, armalcolite, was first discovered in the Apollo 11 samples and was named for the first syllables of the last names of the three Apollo 11 astronauts. The basalts found at the Apollo 11 landing site range in age from 3. Prior to the lunar landings, some scientists thought that the Moon might have always been a cold, undifferentiated body.
The discovery of basalt, which was once molten magma, disproved this hypothesis. Breccias are rocks that are composed of fragments of older rocks. Over its long history, the Moon has been bombarded by countless meteorites. These impacts have broken many rocks up into small fragments. The heat and pressure of such impacts sometimes fuses small rock fragments into new rocks, called breccias. The Apollo 11 samples are referred to as regolith breccias because they formed by fusing material from the lunar regolith at the landing site.
Many fragments can be seen in the breccia photograph shown above. The rock fragments in these breccias can include both mare basalts as well as material from the lunar highlands. The lunar highlands are primarily a light-colored rock known as anorthosite, which consists primarily of the mineral plagioclase. It is very rare to find rocks on Earth that are virtually pure plagioclase. Four months after the first humans reached the moon, Apollo 12 touched down, achieving a much more precise landing on the moon.
Apollo 13 narrowly avoided a near-disaster when on-board oxygen tanks exploded in April , forcing the crew to abort a planned moon landing. All three survived. During the third lunar landing, in January , Apollo 14 , commander Alan Shepard set a new record for the farthest distance traveled on the moon: 9, feet.
He even lobbed a few golf balls into a nearby crater with a makeshift 6-iron. Apollo 15 , launched in July , was the first of three missions capable of a longer stay on the moon.
In the course of three days spent on the lunar surface, achievements included collecting hundreds of pounds of lunar samples and traveling more than 17 miles in the first piloted moon buggy. The Soviet Union had sent a remotely controlled rover to the moon , Lunokhod 1, in See a timeline of the space race and its modern-day version in private spaceflight. After the dramatic accomplishments of the s and s, the major space agencies turned their attention elsewhere for several decades.
So far, only 12 humans—all Americans and all men—have set foot on the moon. The Clementine spacecraft mapped the moon's surface in wavelengths other than visible light, from ultraviolet to infrared. Hiding in the more than 1. The mission's end was spectacular: Prospector slammed into the moon, intending to create a plume that could be studied for evidence of water ice but none was observed.
Since , the Lunar Reconnaissance Orbiter has taken high-resolution maps of the lunar surface. Within the last two decades, lunar exploration has gone truly international—and even commercial. China launched its first lunar spacecraft the same year, and India followed suit in More milestones—both for better and worse—were achieved in In January, another Chinese lander, Yutu-2, made history by becoming the first rover to touch down on the lunar farside.
And in April Israel aimed for the moon with the launch of its Beresheet spacecraft. Unfortunately, even though the spacecraft achieved lunar orbit, it crashed during its attempt to land. Unlike other spacecraft that came before it, Beresheet was built largely with private funding , heralding a new era of lunar exploration in which private companies are hoping to take the reins from governments.
NASA, for one, is partnering with commercial spaceflight companies to develop both robotic and crewed landers for lunar exploration; among those companies are SpaceX, Blue Origin, and Astrobotic.
Amazon CEO Jeff Bezos and Blue Origin have announced the goal of establishing a lunar base near the south pole where people could work and live. SpaceX is developing a spacecraft capable of ferrying astronauts to the moon and Mars , and is also developing a plan to bring tourists to lunar orbit.
The future of spaceflight—from orbital vacations to humans on Mars. And not to be overshadowed by the commercial sector, NASA is planning its own ambitious return to the moon. All rights reserved. Early forays into space The earliest forays into lunar exploration were a product of the ongoing Cold War, when the U.
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