The Universe 13.7 billion years old. We know this age to better than 5 percent uncertainty. It's pretty amazing that such an enormous age, spanning vastly more time than human beings have existed can even be measured. The Hubble Space Telescope was designed to specifically to determine that age of the Universe. As it turned out, ground-based techniques played an even more important role in pinning down this number. In this talk, Dr. Oswalt will discuss how astronomers measure ages of astronomical objects in general, and how the search for the age of the Universe led to the discovery of first dark matter, and then dark energy.

Asteroids and comets may preserve the only records of the physical and chemical processes which marked the beginning of the solar system 4.6 billion years ago. Most asteroids revolve about the sun between the planets Mars and Jupiter and are believed to be the rocky remnants of the minor bodies from which all planets accrete. Comets are bodies that come from far outside the orbit of Pluto, in a dark realm called the Oort Cloud, a large icy debris zone which surrounds the Sun. Over the last decade, the risk of impacts from comets and asteroids has been recognized as substantial and a number of research programs have been undertaken to find and categorize the most dangerous Near Earth Objects (NEOs). Dr. Oswalt will discuss how NEOs are found, the way impact risks are assessed, what the effects of an impact can be, and how the human species might respond to the threat of a major impact.

Just as geophysicists can infer the interior structure of the earth by monitoring the propagation of earthquakes and comparing them to models, astronomers gain insight into stellar interiors by studying the pulsations of stars.  This research domain, called asteroseismology, has shed light on the Sun, white dwarfs, RR Lyraes, and Cepheids, among other types of objects.   Asteroseismological analyses can lead to derivations of stellar parameters such as the rotation rate, density, radius, mass, and envelope thickness.  If the pulsations are stable enough, they may also be used as precise clocks to monitor stellar evolutionary rates and even to detect the presence of unseen companions down to planetary-size.  Here I provide a brief overview of the most important techniques in asteroseismology, using data from the PROMPT array in Chile where appropriate.