Asteroids, as celestial bodies that orbit the Sun, have fascinated scientists for decades. Predominantly located in the main asteroid belt between Mars and Jupiter, they offer key insights into the evolution of the Solar System. While some are as large as mountains, others, smaller, like the size of a bus or a stadium, are equally intriguing. New discoveries point to the possibilities of detecting and tracking even the smallest of these objects, representing a significant step forward in astronomy and planetary defense.

Advanced Method for Detecting Small Asteroids

A team of scientists from MIT has developed a revolutionary method that enables the detection of the smallest asteroids ever discovered in the main asteroid belt. Using an image processing technique called "shift and stack," researchers have successfully identified 138 new asteroids ranging in size from 10 to 100 meters. This technique involves shifting and stacking images to increase the visibility of otherwise faint objects in space.

Prior to this discovery, the smallest asteroids that could be detected in the main belt were about one kilometer in diameter. The new method now allows for the detection of significantly smaller objects, opening up new possibilities for investigating the origins of meteorites and potential threats from space.

Threats Posed by Small Asteroids

An asteroid that caused the extinction of the dinosaurs 66 million years ago was about 10 kilometers in diameter, but such events are extremely rare, occurring every 100 to 500 million years. On the other hand, smaller asteroids the size of a bus or a stadium strike Earth much more frequently, every few years. Such objects can cause localized, but significant damage.

Examples include the Tunguska event of 1908, where an asteroid explosion destroyed a vast forest area in Siberia, and the explosion over Chelyabinsk in 2013, which injured over a thousand people. Understanding these objects is crucial for developing strategies to defend against potential impacts.

Application of New Technologies

The "shift and stack" method was first applied to data from SPECULOOS, a system of telescopes that observe ultracool stars and their planets. Later, researchers applied the technique to data from NASA's James Webb Space Telescope, which provides incredibly sensitive infrared images.

Using JWST, the team analyzed over 10,000 images of the star TRAPPIST-1, known for its planetary system. After processing the data, eight already known asteroids and 138 new objects were discovered, all ranging in diameter from 10 to 100 meters. Some of these asteroids are likely to become near-Earth objects in the future, while one was identified as a Trojan, an asteroid that follows Jupiter's orbit.

Impact on Planetary Science

Discoveries like these provide scientists with unique insights into the processes that shape the Solar System. Small asteroids, often formed from collisions of larger bodies, represent fragments of the Solar System's history. By analyzing their dynamics and composition, researchers can reconstruct events that shaped the planets, including Earth.

Additionally, data on small asteroids are crucial for modeling collisions in space. These collisions play a role in creating new bodies, as well as in potential dangers to Earth. Precise tracking and modeling allow for a better understanding of risks and the development of more effective defense strategies.

Planetary Defense and the Future

One of the key goals of such research is to advance planetary defense. Monitoring objects that could threaten Earth is crucial for developing strategies to deflect or neutralize them. Missions like NASA's DART are already testing the possibilities of changing asteroid orbits by colliding with spacecraft.

New discoveries also lay the groundwork for future space missions. Identifying and tracking small asteroids opens up opportunities for resource mining, such as metals and water, which could support the development of space technologies and deep space missions.

The discovery of the smallest asteroids in the main belt is a significant step forward in astronomy. Techniques like "shift and stack" demonstrate how technology can expand our understanding of the universe. Given the threats that asteroids can pose, as well as the potential opportunities they offer, continued research in this area is vital for the future of humanity.

Source: Massachusetts Institute of Technology