Eight years ago Friday was the first Asteroid Day, a “global awareness movement where people from around the world come together to learn about asteroids and what we can do to protect our planet” from asteroid and comet impacts.
This year’s Asteroid Day has events planned worldwide and online. An excellent Asteroid Day 2023 webpage has been created by NASA’s Jet Propulsion Laboratory, filled with teachable moments, student activities and educator guides on asteroids and comets.
June 30 is a significant date in the history of Earth impacts.
On that date in 1908, according to a 2019 NASA update, “a stony (not icy) body, between 164 and 262 feet in diameter, entering the atmosphere at around 34,000 miles per hour, depositing the 10 to 30 megaton explosion, equivalent to the blast energy of the 1980 Mount St. Helens eruption, at 6 to 9 miles altitude” occurred over Tunguska, Russia.
The Tunguska Event devastated 800 square miles; 80 million trees were flattened. This is the largest such event to occur in modern times and is why Asteroid Day is held every year on June 30, as a reminder to the world that planetary defense against asteroids and comets matters.
We had the Chelyabinsk impact event in 2013, which was historic due to the number of injuries and damage to property it caused — the most ever recorded due to an asteroid or meteorite event.
Chelyabinsk was the most documented asteroid explosion and meteorite fall ever, due to the number of videos, sound recordings, photographs, witness interviews and the recovery of associated meteorites.
Chelyabinsk also improved our knowledge regarding the threat posed by asteroids that are smaller than a kilometer (0.6 mile).
Smaller asteroids like Chelyabinsk pose a greater hazard for damage than previously thought. In December 2018, an event with 40% of the energy release of Chelyabinsk took place over the Bering Sea, reaffirming that such events happen more often than we would like.
Efforts by the United Nations, European Space Agency and the B612 Foundation are working to develop a defensive capability as well as improved asteroid detection.
The following are important highlights in planetary defense that have, or will, significantly improve our protection from an incoming asteroid through detection and deflection.
- NASA has established a Planetary Defense Coordination Office.
- Interagency exercises, such as one held in Maryland, are regularly conducted to test real-world scenarios and responses.
- In 2021, we finally got a space-based telescope mission approved, the NEO Surveyor, that is designed specifically for finding space rocks large and small, like Chelyabinsk. This mission will greatly improve our ability to detect space rocks, especially those that lurk near the Sun (again, like Chelyabinsk) and as a result, cannot be readily seen by Earth-based telescopes. In an email, NEO Surveyor Principal Investigator, Dr. Amy Mainzer, stated that “We’re excited to ramp up work on the spacecraft bus starting this fall in preparation for launch in September 2027.”
- NASA’s Double Asteroid Redirection Test (DART) mission impacted and changed the orbit of an asteroid in September 2022.
- A worldwide community of citizen astronomers, in conjunction with the SETI Institute, is actively participating in planetary defense by making real-time observations using telescopes made by Unistellar. I bought one of their telescopes in order to participate in their citizen science projects.
A last point for you to consider: “The dinosaurs are dead because they didn’t have telescopes or a space program.”
I use this phrase of mine to highlight for my audiences what we need to do to avoid going the way of the dinosaurs who were killed off by an impact in what is now Mexico’s Yucatán Peninsula around 66 million years ago.
The cosmic clock is ticking.