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Light and shadow from distant worlds

Abstract

Exoplanets are distant worlds that orbit stars other than our Sun. More than 370 such planets are known, and a growing fraction of them are discovered because they transit their star as seen from Earth. The special transit geometry enables us to measure masses and radii for dozens of planets, and we have identified gases in the atmospheres of several giant ones. Within the next decade, we expect to find and study a ‘habitable’ rocky planet transiting a cool red dwarf star close to our Sun. Eventually, we will be able to image the light from an Earth-like world orbiting a nearby solar-type star.

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Figure 1: Distribution of known exoplanets in mass and orbital semi-major axis.
Figure 2: Geometry and science yield from transiting planets.
Figure 3: Mass–radius diagram for transiting planets.
Figure 4: Spitzer observations of the giant exoplanet HD 189733b.
Figure 5: Spitzer ‘around the orbit’ observations of the transiting exoplanet HD 189733b.

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Acknowledgements

This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Support for this work was provided directly by NASA, and by NASA through an award issued by JPL/Caltech.

Author Contributions Both authors contributed equally to this work.

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Correspondence to Drake Deming.

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Deming, D., Seager, S. Light and shadow from distant worlds. Nature 462, 301–306 (2009). https://doi.org/10.1038/nature08556

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