Have you ever wondered what’s found in the outer reaches of our solar system? It turns out many, many objects orbit the sun out past Neptune, called trans-Neptunian objects (TNOs). These frozen bodies were formed at the same time as the rest of our solar system – making them close to four and a half billion years old. Determining the sizes of these objects will help us better understand their formation and composition, and could tell us a great deal about the origins of our solar system. One population of these objects is called the Kuiper Belt, shown in the cartoon diagram below.
Pluto was the first Kuiper Belt Object (KBO) discovered in 1930. Since 1992, we have discovered over a thousand KBOs and it is estimated that there are more than 100,000 objects larger than 100km in diameter in this region of our solar system. Our goal is to measure the sizes of a particular category of these objects known as “cold classical KBOs.” These objects are in nearly circular orbits around the sun that have likely not been altered since the formation of the solar system.
To measure the sizes of a KBO, we will use the shadow it casts on Earth as the KBO moves in front of a distant star – an event called an occultation. Check out this video of an asteroid occultation, in which a star turns off briefly as a much closer asteroid passes in front of it. We have proposed to determine the sizes of cold classical KBOs using the occultation method because these objects have been particularly difficult to measure using other techniques.
Making precise measurements of the event from different, nearby locations on Earth, we can determine the size of the object. This is where communities across the Western United States can help us out! Each community that lies within our network will receive a telescope and video camera system. During predicted occultations, every observation site will focus on a specific star in the night sky. Before the occultation is expected to happen, the telescope observer will focus on and record the light coming from the target star. As the KBO moves in front of the star, observers with the path of the KBO shadow will witness the star disappear and then reappear a few seconds later.
Our project will consist of a linked network of 10 telescope sites and eventually 40 sites, across the western United States. Each community participating in RECON will be expected to gather a team of 2-6 members. As a team member, you will be working within your community and collaborating with others in our network to collect astronomical data. The image to the right shows predicted shadow tracks for a 100 km KBO (red track) and a 500 km KBO (gray track).
We are exploring our solar system – jump in and take the next step with us!