An asteroid the size of a house whizzed past earth yesterday. It wasn't close enough to do any damage, and thankfully it is the closest space rock we'll see this year. The asteroid was only discovered last Tuesday by NASA's Catalina Sky Survey near Tucson, Arizona, just nine days before it flew by Earth.
Named 2019 GC6, the space rock was flying past earth this morning at 2:41 a.m. EDT (0641 GMT). At its closest, it was about 136,000 miles (219,000 kilometers), or slightly more than half the average distance between Earth and the moon. The rock was traveling at a relative speed of 12,600 mph (20,300 km/h).
Pretty darn close
According to NASA's Jet Propulsion Laboratory, the rock's diameter is "within a factor of two" of 49 feet (15 meters), which means it may be up to 98 feet (30 meters) wide.
Any object that comes within 8 million kilometers of Earth's orbit and is big enough to cause significant damage is classified as a “potentially hazardous” near-Earth object (NEO).
That doesn't actually mean any of these rocks are at risk of smashing into us. NASA's Planetary Defense Coordination Office is responsible for scanning the skies for potential hazards. Despite a massive effort, many asteroids go undetected until the last minute.
Constant surveillance, not enough
Some aren't even discovered until after they have flown by. Forecasts for the year don't show any more big rocks heading towards us. But in addition to 2019 GC6 another space rock came pretty close to us on March 28. Dubbed 2019 FC1 was less than half as far away from Earth as the asteroid this morning.
Asteroids do pose a threat to Earth, and lots of research is put into thinking about what to do if there is one discovered to be on an impact path.
Harder to destroy than we thought
If you have seen the 1998 film Armageddon, you might be right in thinking NASA will simply send a ragtag team of oil drillers to detonate the asteroid. But recent research shows that this is much harder than previously thought. A study published by Johns Hopkins explores new strategies for asteroid impact and deflection strategies.
"We used to believe that the larger the object, the more easily it would break because bigger objects are more likely to have flaws. Our findings, however, show that asteroids are stronger than we used to think and require more energy to be completely shattered," said Charles El Mir, a recent Ph.D. graduate from the Johns Hopkins University's Department of Mechanical Engineering and the paper's first author.
Understanding asteroids is difficult due to the complexities of space. But researchers have created complex models that propose a variety of ways to accomplish asteroid destruction.