The Unseen Threat: NASA Warns of 15,000 ‘City-Killer’ Asteroids
Humanity may be woefully unprepared for a catastrophic asteroid impact. A recent warning from NASA’s planetary defense officer, Kelly Fast, reveals that up to 15,000 near-Earth asteroids – large enough to devastate a city – remain undetected. This chilling revelation underscores a critical gap in our planetary defense capabilities.
The Challenge of ‘City-Killers’
The greatest concern isn’t the large asteroids we already track, nor the constant stream of small space rocks that burn up in our atmosphere. It’s the mid-sized asteroids, approximately 500 feet in diameter, that pose the most significant threat. These “city-killers,” as they’ve develop into known, are large enough to inflict regional damage but small enough to evade current detection methods. According to Fast, around 25,000 of these asteroids orbit near Earth, yet we only know the location of about 40% of them.
Why Are They So Hard to Find?
Detecting these asteroids is a formidable challenge. Their size and orbit around the sun, alongside Earth, means they don’t reflect much sunlight, making them hard to spot even with the most powerful telescopes. As Fast explained, “even with the best telescope in the world you could not find” them all.
The Near-Earth Object Surveyor Telescope: A Glimmer of Hope
NASA is actively working to improve detection capabilities. The upcoming Near-Earth Object Surveyor space telescope, slated for launch next year, will utilize thermal signatures to identify dark asteroids and comets previously hidden from view. This represents a significant step forward in cataloging potentially hazardous objects.
Detection Isn’t Enough: The Lack of Deflection Capabilities
Even with improved detection, a critical problem remains: we currently lack the means to deflect an asteroid on a collision course with Earth. Even as NASA successfully demonstrated asteroid deflection with the DART mission in 2022 – impacting a small moonlet – replicating this feat with a “city-killer” is far more complex. Nancy Chabot, leader of NASA’s DART mission, stated that we don’t have dedicated deflection spacecraft “sitting around ready to travel.”
Funding and Prioritization: A Critical Hurdle
The development of a robust planetary defense system requires substantial investment. Chabot noted a lack of funding to maintain planetary defenses on standby, highlighting a critical need for prioritization. “We could be prepared for this threat. We could be in highly good shape. We need to take those steps to do it,” she emphasized.
The YR4 Asteroid: A Current Concern
The urgency of this situation is underscored by ongoing monitoring of asteroids like YR4, which has a 4% chance of impacting Earth in 2032. This serves as a stark reminder that the threat is not merely hypothetical.
FAQ: Asteroid Impacts and Planetary Defense
- How big does an asteroid need to be to cause significant damage? Asteroids around 500 feet in diameter are considered “city-killers” and could cause regional devastation.
- Is NASA doing anything to prevent asteroid impacts? Yes, NASA is working to detect and track near-Earth objects, and has demonstrated asteroid deflection technology with the DART mission.
- Are we likely to be hit by a large asteroid? While the probability of a catastrophic impact is low, It’s not zero. That’s why continued monitoring and development of deflection technologies are crucial.
- What is the Near-Earth Object Surveyor telescope? It’s a planned space telescope designed to detect asteroids that are currently hidden from view due to their dark composition and orbital position.
Did you know? The DART mission successfully altered the orbit of an asteroid, proving that we have the technological capability to deflect potentially hazardous objects.
Pro Tip: Stay informed about NASA’s planetary defense efforts by visiting their website and following their updates on social media.
What steps do you think should be prioritized in planetary defense? Share your thoughts in the comments below!
