Asteroid passes between Earth and Moon


A member of a group classified as “potentially hazardous asteroids” by NASA was set to pass between the Earth and the Moon at 5:20 p.m. Wednesday, Sept. 18. 

The asteroid, given the name 2013 RZ53 by scientists, measures only 1 to 3 meters in diameter, and was said to represent no real danger to Earth. It was expected to pass at a safe distance of more than 148,000 miles away from Earth, according to scientists. 

“The expectation when you only have an object that size is when it hits the atmosphere it’s the same as hitting a hard surface,” said Dr. Jim Jordan, Lamar University chairman and professor of Earth Space Science. “Most of them are coming in about three times faster than a 20 mm cannon, so when they confront the atmosphere, they already feel a hard surface. In the upper atmosphere, you often see breakup of objects that size. If it did survive, it would create very little havoc. It would create a small crater a few meters in diameter. It wouldn’t change anything that much.” 

According to data from the Minor Planet Center, a Cambridge, Mass., clearinghouse of information on comets and asteroids, astronomers first observed 2013 RZ53 on Friday, Sept. 13. 

“Because of its size no one was able to see it coming before a week ago,” Jordan said. “Size matters in this case. An object 1 to 3 meters in diameter doesn’t generate its own light. It only gives off light by reflection. The farther away these tiny reflective dots are the more difficult it is to see them.” 

Jordan said there has been dramatic improvement within the last decade in listing or cataloguing potentially hazardous asteroids. 

“Now they are publishing their orbital parameters and pictures of what these asteroids look like in the solar system, and it looks like we are in a beehive,” he said. “The cross-section for us is small to have a collision, and that is why we pay attention right when they are close because then we know the orbital parameters are as accurate as they can possibly be.” 

In February, an asteroid entered Earth’s atmosphere almost 60 times the speed of sound and struck Chelyabinsk over the southern Ural region of Russia, resulting in the injury of 1,491 people, including 311 children, according to RBK, a Russian news organization. The injured included a 52-year-old woman who was flown to Moscow for treatment for a broken spine. 

Jordan referred to the Chicxulub crater off the coast of the Yucatan peninsula when asked how big an asteroid would need to be to make a catastrophic impact on the planet. 

“Some objects, if they impacted anywhere in the world, would affect the entire world,” Jordan said. “A 6-mile diameter asteroid would produce the equivalent of 100 million Hiroshima bombs and basically wipe out the life on Earth.”