Today there is only one system in the world focused on this activity - NASA's Goldstone Solar System Radar, part of the Deep Space Network (DSN). But an idea for a new instrument from the National Radio Astronomy Observatory (NRAO) called the Next Generation Radar System (ngRADAR) would use the Green Bank Telescope (GBT) and other existing and future facilities to increase those capabilities.
Ground-based radar systems are essential for protecting the Earth from asteroid collisions and expanding our understanding of the solar system through high-resolution photography and scalable and robust technologies.
How can humans protect the Earth from "devastating collisions of asteroids and comets"? According to the US National Academies of Sciences, Engineering and Medicine and their Decennial Report on Planetary Sciences and Astrobiology 2023-2032, ground-based astronomical radar systems will play a "unique role" in planetary defense.
Today there is only one system in the world focused on this activity - NASA's Goldstone Solar System Radar, part of the Deep Space Network (DSN). But a new instrument concept from the National Radio Astronomy Observatory (NRAO) called the Next Generation Radar System (ngRADAR) will use the Green Bank Telescope (GBT) and other current and future facilities to increase those capabilities.
"There are many future applications for the radar, such as significantly advancing our knowledge of the solar system, providing information for future manned and robotic space flights, and characterizing dangerous objects that wander too close to Earth," says Tony Beasley, NRAO director.
The scientists recently presented new results obtained using ground-based radar systems at a conference in Chicago.
"NRAO, supported by the National Science Foundation and overseen by Associated Universities, Inc., has been using radar for many years to advance our understanding of the universe. GBT recently helped ensure the success of the DART mission, the first experiment designed to see if humans could successfully alter the trajectory of an asteroid," said Patrick Taylor, observatory scientist and ngRADAR project manager.
GBT is the world's largest fully steerable radio telescope. The maneuverability of the 100 meter diameter dish allows it to view 85% of the sky, and quickly follow objects in its field of vision. Taylor adds: "Supported by Raython Technologies, ngRADAR pilot experiments at GBT – using a low-power transmitter (less than a standard microwave oven) – produced the highest resolution images of the Moon ever taken from Earth. Imagine what we could do with a more powerful transmitter." .
JPL's Marina Brozovich, director of Goldstone and DSN: "The public may be surprised to know that the technology we use in our current radar at Goldstone hasn't changed much since World War II. In 99% of our observations, we transmit and receive from this one antenna. New radar transmitter designs, such as ngRADAR at GBT, have the potential to significantly increase power and waveform bandwidth, allowing for even higher resolution imaging. The system will also be more scalable and robust by using telescope arrays to increase the collection area." .
How does ground-based astronomical radar expand our understanding of the universe? By allowing us to explore our nearest solar system, and everything in it, in unprecedented detail. Radar can reveal the ancient geology and the surfaces of planets and their moons, allowing us trace their development. Radar can also determine the location, size and speed of potentially dangerous near-Earth objects, such as comets and asteroids. Developments in astronomical radar open up new possibilities, renewed investments and interest in collaborations between industry and the scientific community as interdisciplinary ventures.
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Asteroids like any physical object cannot even approach the speed of light.
An asteroid can arrive in an extreme elliptical orbit of 3000 years and then when it is close to us it will be, almost at the speed of light and there will be no time to defend.