Carl Sagan Institute | Cornell University | 2018 Jul 31
Earthbound detectives rely on fingerprints to solve their cases; now astronomers can do the same, using “light-fingerprints” instead of skin grooves to uncover the mysteries of exoplanets.Catalog of our own Solar System Spectra - Credit: JH Madden/NASA
Cornell researchers have created a reference catalog using calibrated spectra and geometric albedos (the light reflected by a surface) of 19 of the most diverse bodies in our solar system: all eight planets, from rocky to gaseous; nine moons, from frozen to lava spewing; and two dwarf planets, one in the asteroid belt (Ceres) and one in the Kuiper belt (Pluto).
By comparing observed spectra and albedos of exoplanets to this catalog of our own home planetary system, scientists will be able to characterize them in reference to the wide range of icy, rocky and gaseous worlds in our home system. ...
The catalog, freely available on the Carl Sagan Institute website, includes high- and low-resolution versions of the data, which shows astronomers the influence of spectral resolution on an object’s identification. In addition, the catalog offers examples of how the colors of the 19 solar system models would change if they were orbiting stars other than our sun. ...
The catalog will enable scientists to prioritize time-intensive, high-resolution observations of extrasolar planets and moons. It also offers insights into what kind of worlds won’t be so easy to categorize without high-resolution spectra. For example, Venus is a rocky planet, but because sunlight reflects from its dense carbon dioxide atmosphere rather than its rocky surface, the colors astronomers observe from such a planet are similar to those of an icy world. On the outer edge of the habitable zone, rocky exoplanets are likely to have dense atmospheres like Venus. Such worlds will require long observations to characterize correctly. ...
A Catalog of Spectra, Albedos, and Colors of Solar System Bodies for Exoplanet Comparison - J. H. Madden, Lisa Kaltenegger
- Astrobiology (online 31 Jul 2018) DOI: 10.1089/ast.2017.1763
arXiv.org > astro-ph > arXiv:1807.11442 > 30 Jul 2018