I understand that we use some sort of spectroscopy of the incident light coming from an explanatory system, but what are the principle techniques behind doing so? Are there any other methods used to detect liquid water other than spectroscopic analysis? I am especially curious about any good published papers that you all might know of pertaining to these mechanisms.
Spectroscopy of exoplanets requires:
-adaptive optics and either a coronagraph or apodized pupil to separate the planet's light from the host star's light
-a detector with a high dynamic range that can accurately register both faint and bright signals
-large telescopes to collect lots of light.
We have already detected water gas in an exoplanet atmosphere. For an example of spectroscopy of a bright gas giant, see
http://arxiv.org/abs/1303.3280
Another technique you can use to look for liquids on other planets is polarimetry. Light reflected from the surfaces of liquids is polarized. With some information about the temperature of the planet's surface, you can deduce that the liquid is probably water. We don't yet have the sensitivity and light-collecting power to do polarimetry of liquid oceans on other planets. However, we have done polarimetry on gas giants:
http://arxiv.org/abs/1109.3116
Thanks again Sarah!!!!!
Hopefully someday we will be able to detect water on even smaller worlds!
Sarah gave a pretty complete answer
hypothetically one could also detect AIRGLOW (emission from atmospheric OH) which would likely indicate the presence of water or at least at an atmosphere capable of supporting water.
In general, the best technique for finding biomass on an earth like planet would be methane absorption bands in the atmosphere. This doesn't work for gas giants
as they naturally have this.
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Atmosphere