It's Asteroid Day: Why Everyone Should Be Aware Of Asteroids

The International Asteroid Day on Saturday, June 30, begs the question: is Earth prepared for the very real threat of an asteroid collision?

Asteroid Day

All around the world, astronomers will be talking about the dangers of near-Earth objects including asteroids as well as the different things that can be done to address these threats.

Those who want to participate in Asteroid Day can find events near them in the events page.

Live streaming is also available during a 48-hour global broadcast about space and asteroids on the Asteroid Day website. Guests include notable personalities in the space industry as well as public figures in policy and entertainment.

Why Learn About Asteroids?

There are millions of near-Earth objects of varying sizes that could be a threat to the planet — and they're notoriously difficult to detect early.

Recently, NASA produced the National Near-Earth Object Preparedness Strategy and Action Plan, which aims to improve the efforts mitigating risks of near-Earth object collisions in the next 10 years.

As CNN notes, globally catastrophic asteroid events such as the one that wiped out dinosaurs only occur every several thousands of years. However, smaller space rocks such as the one that hit Chelyabinsk, Russia, can still inflict considerable damage — and it happens once every 10 to 100 years.

"We will definitely see something like that again in our lifetime," Detlef Koschny, who heads the near-Earth objects group of the European Space Agency, says.

The Chelyabinsk asteroid, about 20 meters wide, generated 20 to 30 times more energy than the first atomic bombs. It injured over 1,000 people.

There's a much larger chance of smaller asteroids striking Earth than large ones due to the sheer volume of them in space. After all, NASA counts about 10 million near-Earth objects larger than 20 meters and 300,000 larger than 40 meters that could potentially be a hazard to the planet.

NASA reportedly estimates that a 10-year notice of an asteroid collision is necessary to adequately prepare for the ensuing strike. Thus, one of the main focuses of the action plan is making sure as many asteroids as possible are catalogued, so astronomers could better track their trajectories and prepare for potential collisions far ahead of time.

The Tunguska Event

Asteroid Day actually marks what's now known as the Tunguska Event, which occurred on June 30, 1908.

According to EarthSky, a fireball was spotted streaking in the sky in remote Russia, and just moments later, an explosion rocked Siberia's Podkamennaya Tunguska River. It released ample energy to have killed reindeer and flattened trees for miles around.

Despite the catastrophe it caused on the ground, the asteroid — or potentially a comet — didn't even hit the Earth's surface. It exploded in the planet's atmosphere, about three to 6 miles above the ground.

Scientists estimate this asteroid to be one-third as big as a football field and traveling at 10 miles per second.