Between Mars and Jupiter, a large number of asteroids drift around in an asteroid belt – also called the main belt – which is home to most of the solar system’s asteroids.
Now astronomers from the European Southern Observatory, which is a collaboration between 11 European countries, have managed to take new pictures of the 42 largest asteroids in the belt. Norway is not part of this cooperation.
Never before have so many asteroids been imaged with such sharpness, and the new images may help to provide new knowledge about the asteroids’ shape and density, reads a press release from ESO.
So far, only three of the major asteroids in the main belt, namely Ceres, Vesta and Lutetia, have been photographed in high resolution, and this has happened during the passage of the spacecraft Dawn and Rosetta from Nasa and the European Space Agency ESA, explains the leader of the asteroid study, Pierre Vernazza from the Laboratoire d’Astrophysique den Marseille in France, in the press release.
– Our ESO observations have given us sharp images of many more; a total of 42, says Vernazza.
–
The new images show 42 asteroids that range widely in both shape and size – the giant Ceres measures 940 kilometers in diameter and is spherical, while the mini putt Urania has a somewhat more complex shape and measures 90 kilometers in diameter.
The images were taken with the instrument Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), which is mounted on ESO’s “Very Large Telescope” – a telescope located in Chile. According to ESO, the new images have “filled a gap” in our knowledge of the solar system, and the hope is that they can help give us a leap forward in asteroid research.
–
The two largest – Ceres and Vesta
The two largest celestial bodies that astronomers have captured images of are the asteroids Ceres and Vesta. The former measures 940 kilometers in diameter, while Vesta measures 520 kilometers in diameter.
–
The two little ones – Urania and Ausonia
At the other end of the asteroid scale of the 42 largest objects in the belt we find Urania and Ausonia. At about 90 kilometers in diameter, they are the two smallest objects that have been studied.
–
Shaped like balls and meat bones
Astronomers found not only variation in the sizes of asteroids, but also when it comes to shape.
Some of the asteroids are spherical – for example Hygiea and Ceres – while others are more elongated in shape. You can see this most clearly on the asteroid Cleopatra, which is shaped like a meat bone.
–
Differences in density provide knowledge of origin
The astronomers from ESO have, by combining the asteroids’ shape and mass, also examined the density of the individual asteroids, and here they discovered during the work that the density of the individual asteroids varies quite a lot.
The two least dense asteroids are Lamberta and Sylvia, both of which have densities of about 1.3 grams per cubic centimeter. This corresponds to a lump of coal, the press release states.
The price for the most dense asteroids among those observed goes to Psyche and Kalliope, which have a density of 3.9 and 4.4 grams per cubic centimeter, respectively – a little more than the density of diamond.
According to the researchers, the differences in the density and composition of the 42 asteroids can provide important knowledge about their origin and how they may have migrated from distant areas of the solar system and into their current position, ESO writes in the press release.
– The observations we have made support the idea that these celestial bodies have wandered around a lot since they were created. Such a large variation only makes sense if they have occurred in completely different areas of the solar system, explains one of the researchers behind the article, Josef Hanuš from Charles University in Prague, according to ESO.
The images of the 42 largest celestial bodies in the asteroid belt is published in an article in Astronomy & Astrophysics.
Reference:
P. Vernazza mfl .: VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis, Astronomy & Astrophysics, 2021. DOI: 10.1051/0004-6361/202141781
We would love to hear from you!
PLEASE CONTACT HERE
Do you have any feedback, questions, praise or criticism? Or tips on something we should write about?
–
–
—
