An incredible photo of the surface of the moon has been captured, which is the highest resolution image of the moon ever taken from the ground.
The full image contains 1.4 billion pixels and shows the Tycho Crater, named for famed Danish astronomer Tycho Brahe. It was captured using a technique called synthetic aperture radar in a collaboration between the National Science Foundation’s Green Bank Observatory (GBO), the National Radio Astronomy Observatory (NRAO), and Raytheon Intelligence & Space (RI&S) using the Green Bank Telescope (GBT).
The GBT, which is a large radio telescope, was fitted with a transmitter last year which allows it to transmit radar signals to space. This recent addition is what allowed the telescope to capture such a detailed image.
“It’s done with a process called Synthetic Aperture Radar, or SAR,” explained Galen Watts, a GBO engineer. “As each pulse is transmitted by the GBT, it’s reflected off the target, the surface of the moon in this case, and it’s received and stored. The stored pulses are compared to each other and analyzed to produce an image. The transmitter, the target, and the receivers are all constantly moving as we move through space. While you might think this could make producing an image more difficult, it actually yields more important data.”
Because of this movement, the researchers can effectively see the target in more detail because they have a greater number of different snapshots to work from. The technology to achieve this kind of image has only recently become available, Watts said: “Radar data like this has never been recorded before at this distance or resolution,” said Watts.
“This has been done before at distances of a few hundred km, but not on the hundreds of thousands of kilometers scales of this project, and not with the high resolutions of a meter or so at these distances. It all takes a lot of computing hours. Ten or so years ago it would have taken months of computing to get one of the images from one receiver, and maybe a year or more from more than one.”
