Probing the dark Solar system: detecting binary asteroids with a space-based interferometric asteroid explorer

Abstract

ABSTRACT With the inception of gravitational wave astronomy, astrophysical studies using interferometric techniques have begun to probe previously unknown parts of the Universe. In this work, we investigate the potential of a new interferometric experiment to study a unique group of gravitationally interacting sources within our Solar system: binary asteroids. We present the first study into binary asteroid detection via gravitational signals. We identify the interferometer sensitivity necessary for detecting a population of binary asteroids in the asteroid belt. We find that the space-based gravitational wave detector LISA will have negligible ability to detect these sources as these signals will be well below the LISA noise curve. Consequently, we propose a 4.6 au and a 1 au arm-length interferometer specialized for binary asteroid detection, targeting frequencies between 10−6 and 10−4 Hz. Our results demonstrate that the detection of binary asteroids with space-based gravitational wave interferometers is possible though very difficult, requiring substantially improved interferometric technology over what is presently proposed for space-based missions. If that threshold can be met, an interferometer may be used to map the asteroid belt, allowing for new studies into the evolution of our Solar system.