Goddard Space Flight Center
Planetary Systems Laboratory

Planetary Systems Laboratory

Two Columns

EPOXI/EPOCH

The Planetary Systems Laboratory is also the home for the Extrasolar Planet Observations and Characterization (EPOCh) investigation, a scientific component of the EPOXI mission. EPOXI re-uses the Deep Impact flyby spacecraft to observe transiting extrasolar planets, and the Earth-as-an-extrasolar planet, while enroute to a 2010 encounter with comet Hartley-2. EPOCh uses the High Resolution Imager (HRI) with its CCD camera to produce very precise photometry of giant extrasolar planets that transit nearby bright stars. Since the HRI is defocused (see Figure 1), EPOCh is able to collect many stellar photons per exposure without saturating the detector, and thus produce very precise photometry of transits. The EPOCh team is using these data to refine the physical properties of the giant planets, search for rings and moons that may orbit them, and search for smaller planets in these systems, down to the size of Earth. Figure 2 shows some early examples of transits for EPOCh targets.

For more information on EPOCh and EPOXI, visit the EPOXI web site at the University of Maryland: http://epoxi.umd.edu/


Figure 1. Image of a bright star showing the defocus of the HRI, enabling very high signal-to-noise photometry.
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Figure 2. Transits of four extrasolar planets observed by EPOCh.

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