The closest approach of a celestial object to earth happened this month when a deadly asteroid zoomed past 10,000 miles - just 5 percent of moon's distance. The 12-foot wide asteroid called 2017 GM approached at 11.5 miles per second. Scientists manning the Mount Lemmon Survey, Virtual Telescope Project, and Tengara Observatories all caught glimpse of the asteroid in its closest approach.
2017 GM asteroid is one of seven celestial objects who went too close to the Earth and the one that is closest. According to NASA, 2017 GM might have approached in the deadly distance some 56 years ago, Space reported. However, comparative data showed that the car-sized asteroid was almost a hundred times the moon distance back then.
Just a week before the potentially catastrophic 2017 GM asteroid, a bigger 10-foot wide asteroid approached at 1,000 miles further in Earth's high orbit. Theoretically, a deadly asteroid approach and subsequent collision can only happen under right circumstances. A celestial rock traveling at speed higher than any spacecraft launched from Earth will likely swerve away. This scenario is much like the Earth's gravity "deflecting" a potential asteroid impact. Think of it in a way a stone "skips" through the water surface.
However, 2017 GM asteroid or any other near-Earth approach may lead to a collision if they are slower and nearer. By then, Earth's gravity will "pull" them down instead of deflecting them. These asteroid impacts were more common some 4.5 billion years ago when there were too many rogue celestial objects flying in the solar system back then, according to UCSB ScienceLine.
Asteroids that are coming too close to Earth have been subjects of research and study recently. The Washington National Science Foundation and NASA funded a project called Killer Asteroids to calculate the potential damage should 2017 GM-like celestial asteroids got tangled in the atmosphere. By simulation standards, "small" asteroids that could be deadly should at least be around 8-foot wide and made of iron.
