Scientists image 42 of the biggest asteroids in our solar system
Just in time to celebrate the 42nd anniversary of the publication of The Hitchhiker's Guide to the Galaxy.
Daphne looks like a teardrop. Ausonia resembles a squished jelly bean. Kleopatra is shaped like a dog bone. Those are just three of 42 asteroids imaged by the European Southern Observatory's Very Large Telescope located in Chile. The asteroids represent some of the largest in our solar system, and the images are helping astronomers learn about the origins of these fascinating space rocks.
"The detailed images of these 42 objects are a leap forward in exploring asteroids, made possible thanks to ground-based telescopes, and contribute to answering the ultimate question of life, the Universe, and everything," ESO said in a statement on Tuesday, making a reference to writer Douglas Adams on the 42nd anniversary of the publication of the sci-fi classic The Hitchhiker's Guide to the Galaxy.
The Very Large Telescope's asteroid observations, including the 3D shapes and densities of the objects, are covered in a paper published in the journal Astronomy & Astrophysics this week. Reconstructions of the asteroids show they tend to be either spherical or elongated, as with the odd-looking Kleopatra.
The data shows the asteroids can have radically different densities. "Our observations provide strong support for substantial migration of these bodies since their formation. In short, such tremendous variety in their composition can only be understood if the bodies originated across distinct regions in the solar system," said co-author Josef Hanus of the Charles University, Czech Republic.
The asteroids in the Very Large Telescope image collection are located in the "main belt" between Mars and Jupiter. The study suggests the least dense asteroids may have formed beyond the orbit of Neptune and then moved to their current spot in the solar system.
The very spherical dwarf planet Ceres is included in the observations. It was visited by NASA's Dawn spacecraft and is one of the most well-studied objects in the asteroid belt. Another famous asteroid on the list is Psyche, the target of an upcoming NASA mission.
Asteroids are a hot topic in astronomy. NASA plans to launch its Lucy mission on Saturday to visit one main belt asteroid and seven others known as Trojan asteroids. Space agencies have also been busy collecting samples from asteroids to bring back to Earth for study. The ESO image project isn't as dramatic as touching down on the surface of an asteroid, but it's filling in some important blanks in the study of these intriguing objects.