Can we develop new techniques to detect life on exoplanets? Previous studies have assessed the likelihood of detecting life through signs of biogenic gases in the atmosphere or a red edge.  Biogenic gases and the red edge could be signs of either single or multi-cellular life.  We propose a technique to determine whether tree-like multi-cellular life exists on extra-solar planets using BRDF, or shadows at different sun angles.  BRDF arises from the changing visibility of the shadows cast by objects, and the presence of tree-like structures is clearly distinguishable from flat ground with the same reflectance spectrum.

We just received a NASA Habitable Worlds grant to continue this work.  See the proposal here.  We are looking for a PhD student to work on the project.  If interested please contact me.

Popular press on our Astrobiology work

Astrobiology Magazine: Seeing the Planets for the Trees.

New Scientist: Could we detect trees on other planets?