Some large space rocks will make a relatively close approaches to Earth this week, an occurrence that has become almost routine as astronomers discover more and more so-called near-Earth objects.

An object known as 137126 (1999 CF9), which has an estimated diameter of between 2,300 feet and a mile, will whip by today at a distance of 9.5 million miles. That’s about 25 times the distance from the Earth to the moon, a standard yardstick for such approaches.

The rock’s orbit takes it out beyond the orbit of Mars at one extreme and within Earth’s orbit at the other, according to NASA.

A strike by such a large object would be devastating.

Meteor Crater, east of Flagstaff, Ariz., was created 50,000 years ago by a rock only 165 feet across, scientists estimate. The crater is about three-quarters of a mile wide and 560 feet deep.

On Saturday, another object, 52760 (1998 ML14), about 3,300 feet across, will come within 22 lunar distances.

And on Sunday, object 2013 QR1, about 420 to 970 feet in diameter, will approach within 8.2 lunar distances, or 3.1 million miles.

One of the premier instruments for tracking such objects is the Pan-STARRS observatory atop Haleakala.