A sizeable asteroid came very close to Earth, in what would have been a close encounter of the disastrous kind if the hunk from space had a tiny bit different trajectory, according to The Planetary Society.
This shows why the United States monitors asteroids, or near Earth objects, that might slam into the home planet, although NASA efforts here are underfunded.
Even if a giant asteroid is discovered to be headed straight for a catastrophic collision with Earth, it is unclear which agencies and nations would attempt to deflect it from the Earth-bound trajectory, what actions would be required (rockets used as bulldozers? Nuclear detonations? Tractor beams?), or how such an effort might be funded.
Asteroid DD45 a week ago came within just 43,500 miles (70,000 kilometers) or so from Earth, streaking over Tahiti. The rock was about 69 to 154 feet in diameter, roughly the size of an asteroid that devastated 800 square miles of Siberia in the early 20th century.
In terms of cosmic space, 43,500 miles is whisker-thin. That is equivalent to much less than two trips around the Earth at the equator, or 18 percent of the 238,000 or so miles from the Earth to the moon (which Apollo astronauts reached in roughly three days).
This space object is about the size of one that entered the atmosphere in 1908 over Siberia, destroying about 800 sparsely populated square miles of forest land.
Key point: DD45 is in an orbit around the sun that intersects the orbit of Earth, and thus DD45 may come whizzing close to the blue planet again.
But the major threat out there is a hefty asteroid, 2004 NM4, a corpulent quarter-mile wide, that will swing dangerously close to Earth on Friday, April 13, 2029. At this point, astronomers think there is more than a 90 percent probability it won’t hit Earth.
If it did, it would cause far worse damage than the Siberian asteroid.