NASA’s OSIRIS-REx collects science treasure from asteroid Bennu
Last Oct. 20, 200 million miles from a planet troubled by a pandemic, civil strife and, in America, a contentious election, NASA accomplished one of those feats that the space agency has become famous for.
A space probe called OSIRIS-REx reached out and touched an asteroid named Bennu and collected a small amount of soil and pebbles left over from the formation of the solar system. In the fullness of time, OSIRIS-REx will carry this science treasure back to Earth, where it is eagerly awaited by researchers.
When OSIRIS-REx launched just over four years ago, scientists thought that the surface of Bennu was smooth, like a sandy beach. When the probe moved into orbit around the Earth-approaching asteroid, scientists discovered, much to their surprise, that Bennu’s surface was strewn with rubble and boulders. The plan to reach out and touch the surface became just a little more complicated.
Fortunately, NASA and its academic partners were up to the task, tweaking the approach technique. They chose a small, relatively safe area designated Nightingale to touch and go. The maneuver was successful. NASA later determined that so much soil and pebbles were collected that some were escaping into space. Scientists were moving quickly to stow the sample head before more was lost. The capsule containing the sample is scheduled to land in Utah in 2023.
Bennu became a target for a sample return mission because of the high carbon content on its surface. Scientists also think that the asteroid has remained relatively unchanged from the very beginning of the solar system. Thus, the sample that in three years will be in the hands of scientists may offer insights, not just of the solar system’s origins, but of life on Earth. Asteroid impacts on a young Earth, rich in organic materials such as carbon, may well have started the long, evolutionary process that led to a world filled with life, including human beings.
The Apollo astronauts were the first human beings to bring home to Earth rocks and soils from another world, our moon. The first moon rocks caused a sensation 50 years ago, almost as much as the first ghostly images of men walking and working on the lunar surface. Some of the moon rocks were placed on public display at the then newly-built Museum of Natural Science in Houston, where people lined up for hours just to see a glimpse of the science treasure.
Between the first Apollo missions and OSIRIS-REx, other missions have brought back rock and soil from other worlds. The Soviets acquired their own moon samples courtesy of a series of uncrewed Luna missions. NASA has recovered samples of solar wind with a probe called Genesis and from the coma of a comet with the Stardust mission. Japan has acquired samples from asteroids, including one that is scheduled to return in December aboard the Hayabusa-2.
Future sample-return missions include the Chinese Chang’e 5, due to launch to the moon in late November 2020. Several countries, including the United States, are contemplating Mars sample-return missions. NASA has proposed that private companies collect moon rocks for future retrieval.
As impressive as robotic sample-return missions have proven to be, nothing quite replaces a human being, trained as a geologist, with the ability to deduce the history of a site at a glance and the context of every rock and area of soil. NASA plans to start sending human beings back to the moon as early as 2024 as part of the Artemis program. Much of what they will do, at least at first, will be collecting geological samples at the lunar south pole, thus far untrodden by human footsteps. One difference from Apollo is the fact that the Artemis astronauts will be staying on the moon long term and thus will be able to study the rocks and dirt they collect on site.
The same principle will be true when humans cross the interplanetary gulfs and land on Mars, a voyage scheduled for some time in the 2030s. Mars, which may have been the abode of life billions of years ago, will pose unique challenges and opportunities for scientists.
Eventually, space-faring geologists will explore other worlds not just for science, but for profit. The moon and the asteroids contain an incalculable amount of mineral wealth, industrial metals, rare earths and others, that will eventually serve as the foundation of a space-based industrial revolution. Thus, science will merge with commerce for the betterment of all humankind.
Mark Whittington, who writes frequently about space and politics, has published a political study of space exploration entitled Why is It So Hard to Go Back to the Moon? as well as “The Moon, Mars and Beyond.” He blogs at Curmudgeons Corner. He is published in the Wall Street Journal, Forbes, The Hill, USA Today, the LA Times, and the Washington Post, among other venues.
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