The sky hides many things in plain sight. Things that, sometimes, to find them we need to use even 9 telescopes. This is what happened to astronomer Henry H. Hsieh, principal scientist at the Institute of Planetary Sciences in the United States, and his colleagues: this same summer they found a strange object that was hidden in the main asteroid belt, between Mars and Jupiter. Classified as “comet-asteroid”, the results of their study have been published in Astrophysical Journal Letters in collaboration with Cornell University.
QN137 2005, a hidden gem among asteroids
The main belt, between the orbits of Mars and Jupiter, is the location of this strange object. It was discovered on July 7, 2021, thanks to data obtained by the Asteroid Terrestrial-Impact Last Alert System (ATLAS) telescope. At the moment it has been baptized with the name of QN137 2005, and it is now that we have discovered its first details: it has a cloud of dust and gas that covers its core, and a tail of more than 720,000 kilometers. Its width is approximately 1,400 kilometers, with an orbit located outside the asteroid belt.
“As such, it is considered a main belt comet, and is one of nearly 20 objects that have currently been confirmed or suspected to be main belt comets, including some that have only been observed to have been active once,” Hsieh points out. “QN173 2005 can be considered both an asteroid and a comet, or more specifically, a main belt asteroid that has recently been recognized to be a comet as well. “
“QN173 2005 can be considered both an asteroid and a comet”
While asteroids are usually rocky and inert, comets are typically icy and active, with elongated orbits and located at distant distances from the Sun. “This duality and blurring of the boundary between what were previously thought to be two completely separate types of objects, asteroids and comets, is a key part of what makes these objects so interesting“Hsieh values.
Although ATLAS was the telescope in charge of discovering it, it took 5 more telescopes located on three continents to continue collecting information on QN137 2005. Thanks to the work of 4 more telescopes, the size and composition of the core could be determined. For now, Hsieh and his colleagues want to continue investigating the secrets behind this newly discovered gem.