NMSUAstronomy

I am interested in the composition and evolution of satellites of the outer solar system as well as Kuiper Belt Objects (KBOs). Moons of the outer planets can tell us much about conditions during the formation of the solar system. I am particularly interested in moons with icy surfaces (Europa, Enceladus, Titania, Triton) and those with atmospheres (Titan and Triton). Triton, Neptune's largest moon, is most likely a captured Kuiper Belt object and so studies of Triton's surface composition and tenuous atmosphere can shed light on the make-up and formation of the KBOs as well as Pluto and Charon.

Ongoing Projects

With the support of my advisor, Dr. Nancy Chanover, I am working on several projects related to objects in the outer solar system:

Uranian moon occultations:
In August and December of 2007, I observed four occultations of Uranian moons with the AGILE camera on the APO 3.5 meter telescope. These occultations occurred during the Uranian equinox, a once-in-42-year event when the equatorial plane appeared edge-on from Earth. I am comparing the observed lightcurves to the output of an occultation software model I wrote to determine the exact midpoint timing and the relative satellite positions and velocities during each event. These results, when compared against the predicted values, will in turn constrain Uranus satellite orbital simulation models.

Phoebe opposition surge:
I am also analyzing data taken during a zero-phase opposition of Saturn's moon Phoebe to verify the presence of an expected "opposition surge" in brightness. The shape of this lightcurve depends on surface properties such as particle size and thus the lightcurve may provide insight into the make-up of Phoebe's surface.

Neptune atmosphere studies:
In the summer of 2008, I plan to observe a stellar occultation of Neptune as part of a collaboration of several astronomers in a study the upper atmospheres of Uranus and Neptune.

Triton atmosphere studies:
Later in 2008, I will apply a General Circulation Model (GCM) that has been used to simulate the Martian atmosphere to conditions found on Triton. Although much thinner, Triton's atmosphere is similar to that of Mars in that its major atmospheric constituent (nitrogen on Triton, carbon dioxide on Mars) condenses and sublimes on the surface as seasons change. The behavior of Triton's atmsophere is of interest as a possible predictor of the state of Pluto's atmosphere when the New Horizons spacecraft makes its closest approach to the Pluto/Charon system in July, 2015.

Workshops

In July 2007, I spent a week at NASA's Jet Propulsion Laboratory participating in the Planetary Science Summer School. I was part of a team of 11 Astronomy and Engineering graduate students who with support of JPL engineers created a mission design for a comet sample return mission.

In February 2008, I attended a one day workshop at NASA Ames Research Center for astronomers planning to observe the impact of the LCROSS mission upper stage booster at the south pole of the Moon currently scheduled for February, 2009.

Meetings

October, 2007: AAS Division for Planetary Sciences meeting

Observations of Time Variable Magnitude Events of Phoebe, Ariel, and Titania
Charles Miller, N. J. Chanover, J. A. Holtzman, A. J. Verbiscer

The Wirtanen Analysis and Surface Probe: Concept for a New Frontiers Comet Surface Sample Return Mission
Matthew Smith, K. Block, S. Byram, B. M. Karpowicz, N. Lanza, J. Masiero, C. Miller, S. Singer, B. Smith, A. Winfield, L. Wye, T. Balint

Support

I am pleased to thank the NMSU Space and Areospace Cluster for a generous research fellowship.