The passage close to Earth of a mountain-sized asteroid expected Friday has reignited discussions among scientists about how to deal with the improbable — but definitely possible — circumstance of an asteroid predicted to hit the planet.
1998 QE2, as the asteroid is designated, will pass Earth at what NASA calls a “safe distance” of about 3.6 million miles — 15 times the distance to the moon, but nonetheless a near miss in astronomical terms — at just before 5 p.m. Eastern on Friday.
The asteroid is not named for the Cunard cruise line’s famous transatlantic ship the Queen Elizabeth II, but rather according to a naming convention based on the year it was discovered.
The asteroid, which is estimated to be 1.7 miles long, but whose shape is still undetectable, will be closely examined by radar telescopes as it passes, NASA said in a statement.
The agency is planning a variety of social media events to mark the passage, and allow the public to listen in to scientists as they debate and discuss what they are learning from the fly-by.
NASA says it “places a high priority on tracking asteroids and protecting our home planet from them” through its Near-Earth Object program.
For more than a decade the program has run Sentry — a computer system that automatically analyses constantly updated astronomical data, looking for asteroids or other objects that might be on a collision course with Earth.
In 2016, NASA will launch a robotic space-probe to one of the most potentially dangerous of the objects in the Sentry database — asteroid (101955) Bennu. The OSIRIS REx probe will enable scientists to study the asteroid and even bring a small sample of it back to Earth for study.
Without years of observation and exact knowledge of an asteroid’s size and shape, it is hard to predict the exact future course they will take as their orbits are erratic, but (101955) Bennu is one of a group of such bodies known as Apollo asteroids which have an orbit that intersects with the Earth’s — creating a small but hard to calculate risk of a collision.
Recent calculations by NASA scientists show a 1 in 1,800 chance that Bennu will collide with Earth in the year 2182.