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Table of Contents
Abundance of asteroids in Earth-like orbits from STEREO images
Introduction
We want to search for asteroids thought to exist along the Earth's orbit that may be leftover material from the formation of our planet. These asteroids always appear close to - or even behind - the Sun in the sky and are therefore difficult to detect from Earth. We will use images taken from the two STEREO probes which have been studying the Sun and its vicinity since 2009. The spacecraft have been slowly drifting along the Earth's orbit and are able to image the sky from different vantage points around the Sun. This way, we will constrain the abundance of asteroids in Earth-like orbits, including any large, hundred-m to km size, objects in unstable paths that are not picked up by surveys and present a long-term impact hazard to our planet.
Main aim of the science case
The objective of the exercise is to use the SECCHI images to search for asteroids along the Earth’s orbit, i.e. with a ~ 1 AU and small e, small i.
This dataset has already been used to study individual asteroids and to survey the region close to the Sun.
The asteroids we are looking for here are smaller and much closer to the spc than in previous studies that use STEREO data.
The perfect result would be to identify all asteroids in the images, including Earth-like asteroids if any. This requires to discriminate between real moving objects and noise or other artifacts on the detector.
Risk analysis
The technical risk is that the search is negative.
This will happen if
there are no objects to be found,
the objects are near or above the limiting magntitude,
the objects are there and are bright enough to be detected but on-board processing removes them from the images.
The scientific risk is that the search does not place a meaningful constraint on the existence of these asteroids.