Asteroids, despite their prominence in our popular imagination — demonstrated by the countless disaster films based on the threat of a rocky mass’s collision with the Earth — have largely remained a mystery, until now.
Using the European Southern Observatory’s (ESO) New Technology Telescope (NTT), astronomers found the first evidence that asteroids can have a highly varied internal structure — a discovery that could in turn enhance our understanding in numerous important areas of research.
By making incredibly precise measurements, Stephen Lowry of the University of Kent, UK, and his colleagues established that the spin rate of the near-Earth asteroid known as “Itokawa” is changing over time — a strong indication that it has a highly varied internal structure.
Lowry’s team used images gathered over more than a decade by the NTT at the La Silla Observatory in Chile among others. By measuring the brightness of the objects in the images and how this changes over time, then combining that evidence with an accurate measurement of the asteroid’s shape, the team were able to make breakthroughs in the understanding of these rocky extraterrestrial bodies.
“This is the first time we have ever been able to to determine what it is like inside an asteroid,” explained Lowry. “We can see that Itokawa has a highly varied structure — this finding is a significant step forward in our understanding of rocky bodies in the Solar System.”
Before astronomers made this leap, the properties of asteroids could only be inferred, leaving experts in the dark over the finer points of structure.
According to Lowry, this new discovery could have important implications and maybe even help us avoid a catastrophic clash!
“Finding that asteroids don’t have homogeneous interiors has far-reaching implications, particularly for models of binary asteroid formation. It could also help with work on reducing the danger of asteroid collisions with Earth, or with plans for future trips to these rocky bodies,” he explained.
This greater understanding of asteroids may also help shed light on what happens when these bodies collide in space and how planets form.
Due to its almost non-existent humidity and clear skies, the Atacama is the world’s premier location for astronomy. Chile is home to almost half the world’s telescope infrastructure, and this is set to increase to over two thirds in the next decade.