The Chilling Reason That Monday Is ‘Asteroid Day' — And Why To Celebrate It In Arizona

Forbes

27-06-2025

Artwork of an asteroid and planet earth.
It's officially Asteroid Day on Monday, June 30, when astronomers from around the world come together to raise public awareness about the risks and opportunities brought by space rocks.
Asteroids have been in the news a lot in 2025. It all started with 2024 YR4, which was predicted to strike Earth on December 22, 2032, before further observations allowed astronomers to refine its orbit and rule out a direct hit. Now, it appears to be heading for the moon instead. Then, the 2008 DG5 asteroid — known to be larger than 97% of others — zipped by Earth in early June.
Tunguska Event
So why Jun. 30 for the United Nations-sanctioned "Asteroid Day?" On that date in 1908, an asteroid about 330 feet (100 meters) in diameter entered Earth's atmosphere and exploded above Siberia in Russia. It destroyed 770 square miles (2,000 square kilometers) of Siberian forest. This is the Tunguska event, the largest recorded asteroid impact on Earth. One hundred seventeen years later, it's a reminder of what can happen at any time.
Meteor Crater
Although stony asteroids tend to explode before they strike Earth in what's known as an airburst — which occurred over Tunguska and also over Chelyabinsk, Russia's seventh-largest city, in 2013 — some leave impact craters on Earth. One of the world's best-preserved and most iconic meteorite impact sites is Meteor Crater, 20 minutes west of Winslow, Arizona. It was formed around 50,000 years ago when a 150-foot-wide iron-nickel asteroid traveling at 26,000 mph carved out a crater nearly a mile wide, 2.5 miles in circumference, and over 550 feet deep. It's a fitting venue for Asteroid Day in Arizona, an event combining science and stargazing.
Asteroid Day In Arizona
The concept of Asteroid Day originated from Apollo 9 astronaut Rusty Schweickart, Danica Remy from the planetary defense non-profit B612 Foundation, and Brian May, Queen guitarist and astrophysicist, who founded it in 2014. This year, Schweickart will speak at Meteor Crater, along with astronomer Scott Manley and Mary Robinette Kowal, author of the Lady Astronaut series. Meteor Crater will host daytime events from 9 a.m. - 5 p.m. MST, with Lowell Observatory from nearby Flagstaff will host evening activities from 5-11 p.m. MST. Expect programs about how scientists look for asteroids, their impacts on Earth, and how Apollo astronauts studied Meteor Crater to prepare for their voyages to the impact-scarred moon. There will also be a talk on sun-grazing comets from Lowell Observatory's comet expert Dr. Qicheng Zhang.
'God Of Chaos'
Bound to be under discussion on Asteroid Day is asteroid Apophis, an asteroid as wide as the Empire State Building is tall, which will come closer to Earth than orbiting geosynchronous satellites in a very rare event. The ominous flyby will occur on Friday, April 13, 2029 — less than four years away. If Apophis did strike Earth, it could spread devastation across a radius of hundreds of miles, according to Space.com, killing millions of people if it struck a highly populated metropolitan area. However, it's not a threat. Despite its enormous size, Apophis will not impact Earth in 2029, but its very close pass is a once-on-a-lifetime opportunity to gather data that could be critical for humanity's future.
Wishing you clear skies and wide eyes.