Don Quixote

Don Quixote was discovered in 1983 and although it has a perfectly comet-like orbit, no cometary activity (a tail or a coma around the object) have been observed. According to protocol, the object was listed as an asteroid. In 2009, we found from observations with the now defunct Spitzer Space Telescope that there actually is a faint coma around Don Quixote that most likely consists of molecular band emission from either CO or CO2. This is discussed in detail here and in this paper. ...

Part of the NEO population is considered to consist of so-called dead comets. Dead comets are comets that have spent a long time as NEOs and have been depleted their volatile inventories in numerous, close encounters with the Sun, i.e., they are extinct comets. They can be identified through their distinctive comet-like orbits and their low, comet-like albedos. The dead comet archetype is NEO (3552) Don Quixote. We observed Don Quixote as part of the ExploreNEOs program, in which ~600 NEOs were observed to derive the diameters and albedos of these objects. Our observations at 3.6 and 4.5 µm were saturated because the target was brighter than expect, revealing something rather unexpected. ...