Asteroid to zoom by Earth on Halloween

CAPE CANAVERAL, Fla. — A large asteroid that scientists discovered only this month will make a relatively close approach to Earth on Saturday, astronomers say, providing one of the best opportunities in years to gather data about a passing space rock.

The asteroid, estimated to be about 1,300 feet in diameter, will shoot past the planet at 22 miles per second at about 1 p.m. on Saturday, Halloween.

Known as 2015 TB145, it will come within about 300,000 miles of Earth, farther away than the moon but relatively close by cosmic measures.

Astronomers hope to capture radar images and other measurements of the asteroid during the encounter, a rarity for scientists who typically rely on expensive robotic space probes to gather information about such rocky bodies. Scientists expect to learn about the asteroid’s shape, dimensions, surface features and other characteristics.

“The close approach of 2015 TB145 … coupled with its size, suggests it will be one of the best asteroids for radar imaging we’ll see for several years,” Lance Benner, an astronomer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said in an article posted on the U.S. space agency’s website.

Aside from pure scientific value, the encounter may help engineers develop better tracking techniques and countermeasures for asteroids that might be on a collision course with Earth.

Small space rocks rain down on Earth constantly, with most disintegrating as they blaze through the atmosphere.

A 65-foot-wide asteroid broke apart over Chelyabinsk, Russia, in February 2013, shattering windows and damaging buildings. More than 1,000 people were injured by flying debris.

NASA is working to map potentially dangerous asteroids and comets that pass within 30 million miles of Earth.

Asteroid 2015 TB145 was discovered less than three weeks ago.

“That such a large object, capable of doing significant damage if it were to strike our planet, was discovered only 21 days before closest approach demonstrates the necessity for keeping daily watch of the night sky,” Detlef Koschny, an astronomer with the European Space Agency, said in a statement.