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Box 7.2 Implementing a New Worlds Science Plan
• Carry out a focused program of computation and theory to understand the architectures of planets and
disks.
• Use the Kepler transit survey to measure the probability that a solar‐type star has a massive terrestrial
companion, and that a red star harbors an Earth‐like planet.
• Perform a microlensing survey from space using the recommended WFIRST to characterize in detail the
statistical properties of habitable terrestrial planets.
• Improve radial velocity measurements on existing ground‐based telescopes to discover planets within a
few times the mass of Earth as potential targets for future space‐based direct‐detection missions.
• Use ground‐based telescopes, including ALMA , AO‐equipped optical/infrared telescopes such as GSMT,
and mid‐infrared interferometry, or space‐based Explorers, to characterize the dust environment around
stars like the Sun, so as to gauge the ability of future missions to directly detect Earth‐size planets in
orbits like that of our own Earth.
• Locate the prime targets for hosting habitable, terrestrial planets among our closest stellar neighbors.
• Use JWST to characterize the atmospheric or surface composition of planets within a few times the size
of Earth, orbiting the coolest red stars. These are the planets that might be discovered by ground‐ and
possibly space‐based surveys.
• Follow up nearby systems discovered by Kepler.
• Assess habitability by using IXO to characterize the frequency and intensity of flares on host stars.
• Use ALMA and CCAT to seek biogenic molecules thought to be precursors to life.
• Develop the technology for an ambitious space mission to study nearby Earth‐like planets.
The Physics of the Universe: Understanding Scientific Principles
Astronomy has made many contributions to our understanding of basic physics and chemistry,
ranging from Newton’s laws of gravitation to the discovery of helium, from providing much of the
impetus for understanding nuclear physics to discovering new types of molecules unique to interstellar
environments. Perhaps the best developed recent example has come from high-precision tests of the
theory of gravity encompassed by Einstein’s theory of general relativity. However, these tests have been
restricted to the situations where gravity is weak, and the strong field expression of the theory still
remains to be tested. The discovery of dark energy and dark matter and the amassed evidence that is at
least consistent with the predictions of the theory of inflation present two more examples where carefully
controlled astronomical measurements contribute to current understanding of fundamental physics. Here
the committee highlights these three topics, mindful of a range of other such opportunities, mentioned
below.
The standard model of cosmology developed in the 1980s and 1990s has been amply confirmed
over the past decade by observations of the cosmic microwave background (CMB) using ultrasensitive
radio telescopes on the ground, balloons, and spacecraft. Using a combination of these and other
observations, astrophysicists have shown that the geometry of space is approximately flat, that the age of
the universe is 13.7 billion years, and that there is nearly five times as much matter in a dark, invisible
form as in normal matter that can turn into visible stars. The past decade also saw strong affirmation of
the remarkable discovery that the expansion of the universe is accelerating.
We can now say that there is a ubiquitous and ethereal substance called “dark energy” that is
expanding the fabric of space between the galaxies at ever faster speeds and accounts for 75 percent of the
mass-energy of the universe today. The effects are so tiny on the scale of an experiment on Earth that the
only way forward is to use the universe at large as a giant laboratory.
Two complementary approaches to understanding dark energy have been considered by this
survey: one on the ground and the other in space. On the ground, the proposed LSST would provide
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