Op-Ed: Good news for a change — NASA proves there’s a defense against killer asteroids
WASHINGTON — NASA’s discovery of Earth’s asteroid Bennu represents a major milestone for the search for extraterrestrial life. For five decades, the space agency has sought to find an asteroid that might have crashed and seeded the solar system with life. So far, it hasn’t turned up a single such object.
The agency’s latest finding is not a meteorite or asteroid, but a rocky object estimated to be about 4 miles (6 kilometers) wide that lies in the “Goldilocks zone” around the sun and orbits at a distance between Earth and Jupiter. NASA has only observed the asteroid three times since 2015, when it was just 4 million miles (6.4 million kilometers) away from Earth.
Its orbit brings it just out of range of Earth’s closest-approaching asteroid, known as 2003 EH71, which passed by Earth on Nov. 25. This puts it far enough away for the chances of a close encounter to be low.
On the other hand, if it re-entered Earth’s orbit just before December 20, the asteroid could become the nearest object to Earth in human history.
“The likelihood is very small,” said Johns-Krull, who led the search for Bennu’s signal at NASA’s Deep Space Network in Hawaii. “It would take a really, really, really close encounter.”
Asteroid Bennu would be “the first known asteroid of this size that will ever pass fairly close to Earth,” Johns-Krull said.
NASA’s Dawn spacecraft on its way to study Bennu, an object that could present a problem for future alien visitations.
The space agency is studying Bennu to learn more about the chemical processes that led to Earth’s water and oxygen, and it may be able to use that knowledge to look for the origins of life elsewhere in the solar system.
Asteroid Bennu has a diameter of between 7 and 8 miles (11-12 km), and may be shaped like an oblong cylinder, or like a ball. NASA says its diameter is about half the diameter of