Amateur Astronomers: Key Players in Earth's Asteroid Defense

In a global effort to safeguard Earth from potentially hazardous asteroids, amateur astronomers have become indispensable players in planetary defense. For nearly three decades, The Planetary Society has spearheaded initiatives that support a network of these enthusiasts dedicated to discovering and tracking near-Earth objects (NEOs). The significance of this endeavor is underscored by the fact that a collision with a large asteroid—one comparable in size to a 50-story building—could unleash destruction equivalent to multiple nuclear bombs, creating craters as expansive as the Grand Canyon.

As of today, there are over 10,000 known asteroids of this magnitude that pass near Earth. While none pose an immediate threat, experts remain concerned about the many undiscovered objects that could endanger our planet. Established in 1997, The Planetary Society’s Shoemaker NEO Grants program exemplifies the organization’s commitment to empowering amateur astronomers. Initially, only a few hundred NEOs had been identified; the grants have since enabled the discovery of nearly 500 NEOs and facilitated detailed investigations of over 19,000 more.

"Though most awardees are technically amateurs, their experience and their facilities allow them to fill crucial roles in planetary defense," said Bruce Betts, Chief Scientist at The Planetary Society, highlighting the essential contributions of these volunteers.

The Shoemaker NEO Grants have supported diverse recipients, from individual students to entire astronomy clubs across the globe. One notable grantee, Robert Holmes, who operates the Astronomical Research Institute in Westfield, Illinois, received funding to enhance his observation equipment. Holmes expressed gratitude for the support, emphasizing the vital role amateur astronomers play in monitoring asteroids using advanced telescopes.

The landscape of asteroid discovery has evolved significantly since the inception of the Shoemaker Grants. Until 2005, these grants were among the few dedicated programs aimed at discovering asteroids. However, following congressional directives to NASA to identify 90% of NEOs larger than a specific size, professional facilities began to dominate the field. Despite this shift, amateur astronomers continue to be pivotal, particularly in follow-up observations that are essential for tracking these celestial bodies.

Dr. Amy Mainzer, a professor in the Department of Earth, Planetary, and Space Sciences at the University of California, Los Angeles, stated, "Since discovering an asteroid is only useful if you’re able to find it again later, taking follow-up observations is crucial. Everyday astronomers really shine in this aspect."

The global distribution of Shoemaker awardees—spanning nearly 25 countries and six continents—ensures that someone is available to observe NEOs at short notice. This collaborative approach enhances the effectiveness of tracking efforts and reinforces the idea that planetary defense is a collective undertaking.

Looking ahead, the upcoming NASA NEO Surveyor mission, scheduled for launch in 2027, aims to achieve the ambitious goal set by Congress two decades ago: the discovery of up to 300,000 new NEOs. However, the spacecraft will face limitations in tracking these objects for extended periods. Thus, the involvement of amateur astronomers will be crucial in monitoring the trajectories of newly discovered asteroids.

As Mainzer noted, "Planetary defense is a team sport. We rely heavily on all of our follow-up observers all over the place." The Shoemaker awardees will not only assist in tracking these asteroids but will also contribute to understanding their physical characteristics, which is vital for developing strategies to redirect any potential threats.

The urgency of these efforts cannot be overstated. The journey towards identifying all potentially hazardous asteroids is still far from complete. Until that day arrives, the contributions of amateur astronomers—often balancing their cosmic pursuits with full-time jobs—will remain a cornerstone of planetary defense initiatives, ensuring that humanity remains vigilant in the face of cosmic threats.