“It was a totally inconsequential occasion – a fortuitous astronomical event,” said Dante Lauretta about February 15, 2013. It was an important day when astronomers paid attention to the wrong asteroid, and a significant collision occurred int the southern Ural region in Russia.
Dante Lauretta is a professor of planetary science and cosmochemistry at the University of Arizona’s Lunar and Planetary Laboratory. He is currently serving as the principal investigator on NASA’s OSIRIS-REx mission. OSIRIS-Rex is presently deployed on the asteroid Bennu to bring samples. Bennu is a potentially hazardous object with a high risk of impacting Earth.
What happened on February 15, 2013?
Professor Lauretta had begun his work on OSIRIS-Rex two years earlier. During that time, an asteroid caught NASA Goddard Space Flight Center: 367943 Duende.
Duende is a micro-asteroid and a near-Earth object, approximately 30 meters in diameter. It was discovered in 2012, and named for Duende, a goblin-like creature from Iberian and Filipino mythology and folklore.
On February 15, 2013, Duende was threatening to come very close to Earth. And it did, at a record distance of 27,700 km from Earth’s surface. Duende’s mass is 130,000 tones. It was estimated that, if it were ever to impact Earth, it would enter the atmosphere at a speed of 12.7 km/s and would have a kinetic energy equivalent to 2.4 megatons of TNT.
Professor Lauretta was called at NASA Goddard Space Flight Center and asked to go on TV and be cheerful and reassuring with the public concerns, telling them they are safe. Little did he know, and people all over the world too, that the Universe had planned a real catastrophe. At 3:20, Universal time, the Chelyabinsk meteorite was making its entrance into Earth’s atmosphere. And the astronomers didn’t see it coming.
Chelyabinsk meteorite was a super-bolide. It was caused by an approximately 20 m near-Earth asteroid with a speed of 19.16 kilometers per second. The light from the meteor was brighter than the Sun, visible up to 100 km away.
Most of the object’s energy was absorbed by the atmosphere. The total kinetic energy before atmospheric impact was equivalent to the blast yield of 400–500 kilotons of TNT range. That means it had26 to 33 times as much energy as that released from the atomic bomb detonated at Hiroshima.
Are we safe from a possible asteroid impact?
Luckily enough, the impact didn’t occur on a populated surface. It caused extensive ground damage a hundred kilometers wide, and a few tens of kilometers long. Russian authorities stated that 1,491 people sought medical attention. Later that day, 19:25 Universal Time, Duende approached Earth.
Professor Lauretta said: “I must be at the TV studios at 5:30 am, found a good pace am checked my Facebook, and I see a shooting star has hit the Earth in Russia and hundreds are harmed. I resembled how am I expected to be protected and cheerful about this occasion?”
The question now is: how safe are we? Scientists say that Bennu won’t hit Earth for the next 125 years. Is it so? Is Bennu even the closest threat, or are scientists looking in the wrong direction once more?