MADRID, 22 (EUROPA PRESS)
NASA’s future James Webb Space Telescope, scheduled to launch in 2021, will observe five remote asteroids, some with moons, to learn more about the composition and history of our solar system, providing clues to how planets moved in their the beginning.
Led by Andrew S. Rivkin of the Johns Hopkins University Applied Physics Laboratory, a team of astronomers will make observations in near and mid-infrared light that will help begin to unravel these mysteries. “The good thing about asteroids is that there are so many,” Rivkin said in a statement. “It means there is always something bright enough and in the right place for Webb to look at.”
This research team plans to study five known asteroids, three in the main asteroid belt and two Trojans, to complement and extend observations from other NASA missions, and to test new techniques with Webb.
They will observe these asteroids in part using the Webb near-infrared spectrograph (NIRSpec), an instrument that breaks light down into its component colors to create a spectrum that researchers will analyze to learn the composition of each object.
A key target in the main asteroid belt is a dwarf planet known as Ceres, which was visited by NASA’s Dawn spacecraft from 2015 to 2018. Ceres has ammonia-containing minerals on its surface, leading researchers to wonder if it formed further in the solar system. or if the dwarf planet incorporates material from further away.
By obtaining Webb measurements at wavelengths longer than those obtained by Dawn, the team will be able to use the unique and complementary dataset to verify whether the above conclusions about its surface composition are correct. At the same time, observations will help establish a technique for observing targets that may be a little too bright to observe at these wavelengths with Webb.
Pallas, the second largest asteroid in the main belt and a dwarf planet candidate, is another important target. Due to its orbit, Pallas would be very difficult for a spacecraft to visit. By observing it with Webb, this team will collect data on its surface and composition that would otherwise be difficult to obtain. The team will also compare measurements from Pallas and another dwarf planet candidate, Hygeia, with data on Ceres, helping them identify the similarities and differences of their targets. These comparisons may offer clues to the formation histories of these inner planet building blocks.
The target Trojan asteroids, Patroclus and Hektor, are very different from Webb’s other asteroid targets, not only because of their location near Jupiter, but because they also have moons. Hektor is a binary and its moon orbits closely. In contrast, Patroclus and its moon have more space between them. “Webb will allow us to investigate each asteroid and moon separately,” Rivkin explained. “By studying their moons, we will also be able to examine how each of these binaries formed and compare these two systems.” The data will also help astronomers refine models of how Trojan asteroids were captured in their current orbits.