Session V1: Plenary Session III

Exoplanets: Interiors, Atmospheres, and the Search for Habitable Worlds

For centuries people have wondered, ``Are we alone?'' With over 250 exoplanets known to orbit nearby stars, this question has moved from science fiction to mainstream study. Now that the existence of exoplanets is firmly established, a new era of ``exoplanet characterization'' has begun. A subset of exoplanets--called transiting planets--pass in front of their stars as seen from Earth. Transiting planets have opened a whole new opportunity for exoplanets, because their physical properties, including average density and basic atmospheric properties, can now be routinely measured. The race to find habitable exoplanets has accelerated with the realization that big Earths orbiting small stars can be both discovered and characterized with current technology. These ideas will lead us down a path to the ultimate goal of space-based discovery and characterization of Earth analogs.   

New Paths to Fundamental Physical Law

The field formerly known as High Energy Physics is less and less confined to experiments conducted at accelerators. While it will likely take the Large Hadron Collider at CERN to find the Higgs boson or its surrogates, we are using very different techniques to explore other unknown parts of the Standard Model and the 95\% of the universe that lies outside it. The unanswered questions lead to experiments 2.5 km below the earth's surface and ones 1.5 million km above it. In these ventures, particle physicists will join with nuclear physicists, astrophysicists, and astronomers to try to answer that question of interest to five-year olds and sages alike: what is the universe made of?   

Probing matter at the extremes: new frontiers in high energy density physics

The ability to experimentally study scaled aspects of the explosion dynamics of core- collapse supernovae (massive stars that explode from the inside out) or the radiation kinetics of accreting neutron stars or black holes on high energy density (HED) facilities, such as high power lasers and magnetic pinch facilities, is an exciting scientific development over the last two decades. [2] Additional areas of research that become accessible on modern HED facilities are studies of fundamental properties of matter in conditions relevant to planetary and stellar interiors, protostellar jet dynamics, and with ultraintense short-pulse lasers, strong field effects, possibly relevant to gamma-ray burst dynamics. With the added tool of thermonuclear ignition on the National Ignition Facility, excited state (``multi-hit'') nuclear physics studies, possibly relevant to nucleosynthesis, may also become possible. Techniques and methodologies for studying aspects of the physics of such extreme phenomena of the universe in submillimeter scale parcels of matter in the laboratory will be discussed. [2] ``Experimental astrophysics with high power lasers and Z pinches,'' B.A. Remington, R.P. Drake, D.D. Ryutov, Rev. Mod. Phys. 78, 755 (2006).