Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-01-11
Astronomy and Astrophysics
Astrophysics
41 pages, 7 figures. Icarus in press
Scientific paper
10.1016/j.icarus.2008.01.002
We propose that astronomers will be eventually be able to discriminate between extrasolar Earth-like planets with surface oceans and those without using the shape of phase light curves in the visible and near-IR spectrum. We model the visible light curves of planets having Earth-like surfaces, seasons, and optically-thin atmospheres with idealized diffuse-scattering clouds. We show that planets partially covered by water will appear measurably brighter near crescent phase (relative to Lambertian planets) because of the efficient specular reflection (i.e., glint) of starlight incident on their surfaces at a highly oblique angle. Planets on orbits within 30 degrees of edge-on orientation (half of all planets) will show pronounced glint over a sizeable range of orbital longitudes, from quadrature to crescent, all outside the glare of their parent stars. Also, water-covered planets will appear darker than a Lambertian disk near full illumination. Finally, we show that planets with a mixed land/water surface will polarize the reflected signal by as much as 30-70 percent. These results suggest several new ways of directly identifying water on distant planets.
Gaidos Eric
Williams Michael D.
No associations
LandOfFree
Detecting the Glint of Starlight on the Oceans of Distant Planets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Detecting the Glint of Starlight on the Oceans of Distant Planets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detecting the Glint of Starlight on the Oceans of Distant Planets will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-605551