IMAGE: Comet 2019 LD2 (ATLAS) as seen by the Hubble Space Telescope. CREDIT: Hubble Space Telescope/Bryce Bolin.
Our first story of the day comes from our very own Planetary Science Institute, and it is fresh off the press release list. For once, we’re going to talk about the science behind a comet and not just whether or not it will become a naked-eye wonder.
Let’s start with some background information. When I was working as an intern, I learned that there were basically two types of comets: long-period comets and Jupiter Family comets. Long-period comets orbit the Sun on a scale of 200 or more years. Jupiter Family comets orbit the Sun from inside the orbit of Jupiter. Then I learned there were also short-period comets that orbit from the Kuiper Belt inward to Jupiter.
There’s another type of object that somewhat falls into the cometary category, however. They’re called Centaurs. The press release explains: Centaurs are icy bodies in unstable orbits between Jupiter and Neptune, and cross the orbits of one or more of the giant planets in their journey around the Sun; the gravity of these planets provide rapid dynamical evolution of the objects, and either eject them ...