Asteroid Up to 1,800 Feet Wide is One of 14 to Pass Earth This Week

There are not one, not two, but 14 asteroids on track to pass Earth this week—one of which is 1,800 feet across, making it wider than the Empire State Building is tall.

According to CNEOS data, the object (2019 UO) is projected to fly by Earth at 9.4 kilometers per second on Friday January 10, 2020.

It is expected to do so at a minimum possible close-approach distance of 0.03376 astronomical units (au) or 13.07 lunar distance (LD), meaning it is a little over 13 times the Earth-Moon distance.

That is a minimum distance of 3,138,000 miles or 5,050,000 kilometers. The Earth has a circumference of 24,901 miles or 40,075 kilometers.

The closest miss this week will be on Thursday January 9, 2020, with object (2020 AT1) with a minimum possible close-approach distance of 2.46 LD or 0.00631 au—which is still 23 times as long as the circumference of the Earth.

It is estimated to be between 8.3 and 19 meters wide.

Near-Earth Objects (NEOs)

NASA catalogues any asteroid—or near-Earth object (NEO)—that is expected to make a close approach. Their definition of "close" may seem quite loose in layman's terms as the database includes NEOs that miss the Earth by millions (and sometimes ten millions) of kilometers.

To qualify, they must be within 121 million miles (195 million kilometers) of the Sun as well as within 30 million miles (50 million kilometers) of Earth's orbit around the Sun.

NASA defines NEOs as "comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighborhood."

While a comet is mostly ice and dust forged in the cold Outer Solar System (Jupiter and beyond), asteroids are space rock from the relatively warm Inner Solar System (Mercury to Jupiter) but more specifically the area between Mars and Jupiter. Both are considered space debris left over from the formation of the Solar System some 4.6 billion years ago. As such, they could prove hugely informative on how planets were formed in the early universe.

"As the primitive, leftover building blocks of the solar system formation process, comets and asteroids offer clues to the chemical mixture from which the planets formed some 4.6 billion years ago," states NASA.

"If we wish to know the composition of the primordial mixture from which the planets formed, then we must determine the chemical constituents of the leftover debris from this formation process—the comets and asteroids."

Last week (December 30, 2019 to January 5, 2020), saw 18 NEOs fly by. The previous (December 23 to December 29, 2019) saw 21—so this week might seem reasonably quiet in comparison.