Astronomers Delve into Internal Composition of Asteroid for First Time [VIDEO]

Using a European Southern Observatory (ESO) telescope, astronomers, for the first time ever, have managed to study the internal structure of a small peanut shaped asteroid.

Not much is known about the anatomy of an asteroid. In order to gain some information on these small airless celestial objects, astronomers decided to take a peek inside the asteroid 'Itokawa'. Using ESO's New Technology Telescope (NTT), astronomers made precise measurements of the density of the near-Earth asteroid and discovered that it has a highly varying internal composition.

The team led by Stephen Lowry (University of Kent, U.K.) and colleagues believe that this study will help in gaining insight on the formation of asteroids and planets. They also hope to discover what lies beneath the surface of the asteroid.

The small asteroid (25143) Itokawa, was discovered in 1998. In 2005 Japanese space probe Hayabusa arrived at Itokawa and collected samples of the asteroid material returning to Earth in 2010. This solar powered vehicle also revealed that the asteroid has a strange peanut shape.

To investigate into the internal structure, the researchers analyzed the images taken by ESO's NTT from 2001-2013 at the La SIlla Observatory in Chile. They used these images to measure the variations in brightness of Itokawa as it rotates.

Using the information of the spin timing they figured out the accurate rotation period of the asteroid and also verified how it alters over time. Through the data the astronomers explored the interior structure of the asteroid and revealed the complexity of the core of the asteroid.

"This is the first time we have ever been able [to] determine what it is like inside an asteroid," Stephen Lowry of the University of Kent, UK, said in the news release.

"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."

The researchers realized that the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP), sunlight's effect on an asteroid or a heavenly body's spin, affects Itokawa too.

The YORP effect occurs when the light absorbed from the Sun is re-emitted in the form of heat from the surface of the object. If the shape of the object is uneven the heat radiated is also not even.

Since Itokawa has a peanut-like shape, the uneven heat emitted from the surface form tiny continuous torque on the celestial body. This in turns alters the spin rate of the object.

Lowry and colleagues had noticed this YORP effect for the first time on a small asteroid 2005 PH5 and later named 54509 YORP, reports iSciencetimes.

The YORP effect increased the spin rate of Itokawa slowly. But the change in the rotation period was extremely small-just 0.045 seconds per year. This occurs only if two parts of the asteroid have different densities.

Usually, asteroid composition is estimated by overall density measurement. However, looking at Itokawa's varied internal structure, researchers speculate that it formed when two asteroids bumped into each other and fused together.

"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," Lowry said.

The findings appear in the journal Astronomy & Astrophysics.