Tuesday 17th Sept – Assoc Prof Chad Trujillo

This months meeting we have Associate Professor Chad Trujillo from Northern Arizona University an Erskine visitor to the University of Canterbury. He will be giving us a presentation after the usual business conducted at the meeting from 8pm.

Active Asteroids, Extremely Distant Trans-Neptunians and Planet X

I’m currently working on two independent research projects, the most
recent being a search for active asteroids among freely available
archival Dark Energy Camera (DECam) data collected from the 4m Cerro
Tololo Blanco telescope in Chile. Most of the main belt asteroid
population has been serendipitously imaged during the Dark Energy
Survey and other research projects using DECam, however, nobody has
examined the images. We have an ongoing Citizen Science project at
activeasteroids.net where we have extracted millions of thumbnail
images of all minor planets in the public DECam dataset and asked
thousands of volunteers to examine the images to look for comet-like
activity among the main belt asteroids. To date, we have identified
comet-like activity from over a dozen objects that was previously
unrecognized. The known active asteroids, although fewer than 60 in
number, are very interesting, as about half of them are suspected to
be driven by water ice like the comets are. This suggests that there
could be an as-yet-unidentified reservoir of water ice hidden in the
main asteroid belt which has implications for the solar system’s
formation as well as future space travel.

The other project I have been working on for over a decade is a survey
of the most distant parts of the solar system. The trans-Neptunian
belt (aka the Kuiper Belt) is fairly well-studied and its history and
dynamics are controlled by Neptune at 30 au. However, further out, the
Extreme trans-Neptunian Objects (ETNOs) have eccentric orbits with
closest approach beyond Neptune’s gravitational influence and carry
some of them out to thousands of au from the Sun. There are only about
a dozen such objects and their origin is a mystery but sheds some
light on the solar system’s formation and hints at the possibility
that there could be an as-yet undiscovered super-Earth mass planet in
our solar system beyond 100 au.