In November 2000 following a national competition, NASA selected a science team for the Space Interferometry Mission. The team includes the Principal Investigators of ten key science projects and five mission scientists. The SIM Science Team currently drives the science of the SIM mission.

As an instrument of unprecedented sensitivity, SIM will provide the science team members with a new window on the universe through which they will investigate a wide range of topics within and beyond our Milky Way galaxy. These include:

• Searches for low-mass planets and solar systems similar to our own. SIM will be able to detect and characterize planets down to a few Earth masses.

• Calibration of the cosmic distance scale by determining the distance to important "signposts" in our galaxy SIM's precision will produce measurements several hundred times more accurate than what is possible today. This will allow for the creation of a much-improved "road map" of the Milky Way.

• Fundamental stellar astrophysics Combining SIM's precise distances with other data will help astronomers understand what makes stars shine and how the elements that constitute the building blocks of life have formed.

SIM PlanetQuest is the first space project designed to use interferometry to measure the positions of stars. It will do so to a degree of accuracy unprecedented by earlier groundbased or space-based measurements. During the course of its five-year mission, SIM, operating from 450 - 900 nm, will complete a survey of the whole sky, using interferometric techniques to tie the optical reference frame it defines firmly to the radio reference frame already established.

SIM will survey thousands of stars for planets. The stellar components all along the main sequence of the Hertzsprung-Russell diagram will be measured to extreme accuracy, permitting this workhorse of stellar evolution to be better tied to the physics of stellar interiors. The stellar mass function, including the effects of metallicity, will be better understood.

Exotic objects, including neutron stars, black holes, and "dark matter" candidates will come into sharper focus. SIM observations will test the predictions of the behavior of stars in gravitationally complex systems including globular clusters and in galaxies.

Observations by SIM will extend the "bootstraps" of the fundamental distance scale to nearby galaxies, instead of it staying limited to our local spiral arm. Ultimately, SIM's observations will bear on our understanding of quasars and the distant universe and on the cosmological theories of the origin of the universe.

Whitepaper: "SIM PlanetQuest: A Mission for Astrophysics and Planet-Finding" (PDF)

Science with the Space Interferometry Mission (PDF)

SIM Science Investigations