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Apollo 15 landing site is strikingly clear in image captured from Earth

New radar image of the Apollo 15 landing site, located with respect to prominent lunar features
New radar image of the Apollo 15 landing site, located with respect to prominent lunar features (Image credit: Sophia Dagnello/NRAO/GBO/Raytheon/AUI/NSF/USGS)

Scientists captured this striking image of the Apollo 15 landing site by shooting a powerful radar signal from Earth into space and bouncing it off the lunar surface.

The thin, meandering channel running through the middle of the image is the Hadley Rille, a scar left on the moon after past volcanic activity, likely a collapsing lava tube, according to a statement from the National Radio Astronomy Observatory (NRAO). The circular dent pictured near the rille is Hadley C, a crater about 3.7 miles (6 kilometers) in diameter. 

Scientists spent two years developing the technology to take these detailed images of the moon from Earth, and now, they can capture snapshots of lunar objects as small as 16.4 feet (5 meters) across from about 238,855 miles (384,400 kilometers) away. In the future, the researchers plan to develop the technology further, to the point where they can throw radar signals out to the far reaches of the solar system and capture images of Uranus and Neptune, which at their closest are 1.6 billion miles (2.6 billion km) and 2.7 billion miles (4.3 billion km) from Earth, respectively, according to Space.com.

Related: Supermoon photos: Full moon rises across the globe 

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This radar image shows the region where Apollo 15 landed in 1971. To find the landing site, follow the Hadley Rille (the snake-like line) down from the Hadley C crater (the nearby dent); the Apollo 15 landed near where the rille begins to shoot off towards the right side of the image. (Image credit: NRAO/GBO/Raytheon/NSF/AUI)

"The planned system will be a leap forward in radar science, allowing access to never-before-seen features of the solar system from right here on Earth," Karen O'Neil, site director of the Green Bank Observatory in West Virginia, said in the NRAO statement.

But how does the new technology work? Scientists attached a radar transmitter to the Green Bank Telescope (GBT), the largest fully steerable radio telescope on Earth. Thus equipped and aimed at the moon, the telescope could transmit radar signals to the lunar surface. These signals then ricocheted back toward Earth, where they were caught by the NRAO's Very Long Baseline Array, a network of observation stations with large antenna dishes scattered around the U.S.

The NRAO, the Green Bank Observatory and Raytheon Intelligence & Space, the company that developed the radar transmitter, captured the new images of the Apollo 15 landing site in November 2020, while running a proof-of-concept test of the technology. They are now finalizing a plan to develop an even more powerful radar system that can snap high-resolution images of both near-Earth objects and the solar system's outermost planets.

"We've participated before in important radar studies of the Solar System, but turning the GBT into a steerable planetary radar transmitter will greatly expand our ability to pursue intriguing new lines of research," Tony Beasley, director of the NRAO and vice president for Radio Astronomy at Associated Universities, Inc., said in the statement.

Originally published on Live Science. 

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