The team's detection technique, which identified 138 space rocks ranging from bus- to stadium-sized, could help track potential asteroid impact threats.

The asteroid that wiped out the dinosaurs is estimated to have been about 10 kilometers across, roughly the width of Brooklyn, New York. Such massive impactors are predicted to strike Earth once every 100 million to 500 million years.

Figure 1. MIT Astronomers Discover Smallest Asteroids in Main Belt

In contrast, much smaller asteroids, around the size of a bus, can hit Earth more frequently, every few years. These “decameter” asteroids, typically tens of meters in diameter, are more likely to break free from the main asteroid belt and become near-Earth objects. If they impact, these small but powerful rocks can cause significant regional damage, as seen in the 1908 Tunguska event in Siberia and the 2013 Chelyabinsk explosion in Russia. Observing decameter-sized main-belt asteroids would offer valuable insights into the origin of meteorites. Figure 1 shows MIT Astronomers Discover Smallest Asteroids in Main Belt.

An international team led by physicists at MIT has developed a method to detect the smallest decameter asteroids within the main asteroid belt, a region between Mars and Jupiter filled with millions of orbiting asteroids. Previously, the smallest asteroids detectable in this area were about a kilometer in diameter. With the new technique, scientists can now identify asteroids as small as 10 meters across.

In a paper published today in Nature, the researchers reveal that their method has enabled them to discover over 100 new decameter-sized asteroids in the main asteroid belt. These space rocks, ranging from the size of a bus to several stadiums wide, are the smallest asteroids ever detected in this region.

The researchers believe their new approach could be crucial for identifying and tracking asteroids that may approach Earth.

“We have been able to detect near-Earth objects down to 10 meters in size when they are really close to Earth,” explains lead author Artem Burdanov, a research scientist in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “Now, we can spot these small asteroids much farther away, enabling more precise orbital tracking, which is essential for planetary defense.”

The study’s co-authors include MIT planetary science professors Julien de Wit and Richard Binzel, along with collaborators from several institutions, including the University of Liege in Belgium, Charles University in the Czech Republic, the European Space Agency, and Max Planck Institute for Extraterrestrial Physics and the University of Oldenburg in Germany.

Image shift

De Wit and his team, originally focused on exoplanet searches, have now applied their expertise to identify asteroids in our solar system. By using a technique called “shift and stack,” which involves shifting and combining multiple images of the same area, they can detect faint asteroids among the noise in data originally gathered for exoplanet research. This method, developed in the 1990s, was enhanced with modern GPU processing, enabling the team to efficiently analyze massive amounts of data. Their approach successfully identified numerous new asteroids in the main asteroid belt, using data from the SPECULOOS survey and a telescope in Antarctica.

An unexplored space

In their new study, researchers used NASA’s James Webb Space Telescope (JWST) to detect small asteroids in the main asteroid belt, benefiting from the telescope's infrared sensitivity. This allowed them to spot eight known asteroids and discover 138 new ones, some just tens of meters across — the smallest ever detected in the belt. The findings suggest a more efficient process of asteroid fragmentation and may help track objects that could become near-Earth objects. This research opens a new frontier in asteroid studies, highlighting the role of modern technologies in revealing previously undetected populations of space rocks.

Source: MIT News

Cite this article:

Janani R (2024), MIT Astronomers Discover the Smallest Asteroids Ever Observed in The Main Belt, AnaTechmaz, pp. 138