Ryan Park, Assistant Associate Professor of Astronautics Practice at USC Viterbi School of Engineering, was recently appointed Vice Chairman of the X2 – Cross-Division AF Commission Solar System Ephemerides.
Below is a question-and-answer session on its importance and the future of advances in understanding the positioning and trajectories of various objects in space.
What is the commission’s mission?
Commission X2 (Cross-Division AF Commission Solar System Ephemerides) was created in 2015, from the merger of the functions of the previous Commission 4 “Ephemerides” and Commission 20 “Positions and movements of minor planets, comets and satellites ”.
Ephemeris include the position, speed, and orientation of bodies other than Earth over time. The main objective of this commission is to support the development of high precision ephemerides, and the products / services that distribute them, for all bodies of the solar system: planets, dwarf planets, asteroids, comets, distant objects, natural satellites of planets and asteroids. .
Why is this important right now?
The functions of Commission X2 have always been important; there are many practical and academic reasons that require precise information on orbit and rotational characteristics. You could say it’s important right now because our ability to observe distant and faint objects is improving, so we want to make sure that we have the ability to process the data and produce high precision ephemeris.
What are the opportunities offered by a better understanding of the trajectories of distant objects?
Unless we have observations taken by a spacecraft (i.e. overflight), the trajectories of distant objects are mostly determined from telescopes on the ground or in space. With the planned LSST and NEO Surveyor, we will be able to observe and discover many more planetary objects. Understanding the trajectories of distant objects would make it possible to improve the dynamic model of our solar system, and possibly to impose a constraint on the existence of another planet.
What are the main challenges / problems of the commission that it is trying to solve?
The following is taken from the 2018-2021 report: Asteroid and comet discoveries are expected to continue to increase in the coming years, driven by near-Earth asteroid readings, but also by starting the operations of the Vera Rubin Observatory (formerly known as the Large Synoptic Survey Telescope), an extremely powerful instrument whose objectives are a complete inventory of small objects in the solar system. In this regard, the recent switch to ADES (data sharing format) is particularly important, as the sharp increase in the number of discoveries could underline the ability of the Minor Planet Center to rapidly produce orbits and ephemeris. reliable, also in view of recent discoveries of new classes of small bodies, such as interstellar objects and apparently asteroid objects from the Oort Cloud (a predicted collection of icy objects farther away than the rest of the solar system).
How does this impact space missions?
Knowing the orbit and rotational characteristics of a target body is a critical first step in designing and navigating a mission. For example, the Mars orbit presented in this article was used by the Mars2020 flight project and played an important role in the successful landing of the Perseverance rover.
How does this potentially impact events on Earth?
One of the most important issues for potential impact events on Earth is finding / discovering potentially hazardous objects (PHOs), as well as predicting their orbit. The previously mentioned projects (LSST and NEO Surveyor) would provide important data for both discovering and determining the orbit of PHOs.