Unveiling the Hidden Threat: Asteroids Lurking in the Sun’s Glare and the Quest for Advanced Detection

Asteroids with the potential to pose a threat to Earth are lurking in the sun’s glare, making them difficult to detect using current observational methods. The Chelyabinsk meteor incident in 2013 highlighted the danger of such hidden space objects, as it arrived from the direction of the sun, catching astronomers off guard. While most near-Earth asteroids have been identified, there are still countless others, including larger ones capable of causing significant damage or even triggering mass-extinction events, whose trajectories remain unknown.

The challenge lies in surveying asteroids near the sun, where both solar glare and atmospheric conditions impede visibility. Ground-based telescopes have a limited window of opportunity to observe this region, and their effectiveness is hampered by atmospheric distortions. The potential threats include “city killers” – asteroids over 460 feet (140 m) in diameter – and even rarer “planet killers,” exceeding 3,280 feet (1 km) in diameter.

To overcome these challenges, a new generation of space telescopes equipped with infrared detectors is proposed. Current space telescopes, like NEOWISE, have limitations and are unable to observe the sun’s vicinity. Planned missions, such as NASA’s NEO Surveyor (launching in 2027) and ESA’s NEOMIR (anticipated launch no sooner than 2030), aim to address this issue. These telescopes will orbit at the first Lagrange point (L1) between Earth and the sun, allowing them to scan for asteroids near the sun’s glare without interference.

The infrared capabilities of these telescopes will enable the detection of asteroids based on their thermal emissions, even in the sun’s glare. With the ability to scan specific regions around the sun regularly, these space telescopes should significantly improve our ability to identify potentially hazardous asteroids. The hope is that, with advanced warning, appropriate measures can be taken to mitigate the impact risk, whether it involves deflecting the asteroid or issuing warnings and evacuation plans for affected areas.

Despite the ongoing reliance on ground-based methods until the new space telescopes become operational, astronomers stress the importance of conducting thorough surveys to enhance our understanding of these celestial threats. The goal is to reduce uncertainty and improve our preparedness for potential asteroid impacts, emphasizing the need for continued vigilance and exploration of the cosmos.