Category Archives: biology

Bacteria for greening Mars?

My colleague Bob Fosbury from ESO shares (among many other beautiful and instructive photographs and anecdotes) and interprets intriguing spectra of samples of Atacamanian halites on his flicker account. These halites are populated by extremophiles, bacteria referred to as Chroococcidiopsis. Most interestingly, chlorophyll fluorescence between about 640nm and 780n can be clearly seen, opening possibilities to eventually search for chlorophyll signatures through fluorescence spectroscopy (and not, as usually suggested, through reflection).

Atacama halite and spectra


Earths Evolution over the past 5000 Mio years

Following the Earth’s history since its formation, we can identify some milestones of the Evolution of Life. Photosynthetic bacteria were formed very early (approx 3500 Mio years  ago), and had profound impact on the Earths atmosphere. They still exist, and survive in the most extreme environments on Earth. If one can rewind the “Tape of Life”, would they still emerge?

Animation: 1 second corresponds approximately to 100 Mio years (m4v  960×540, 26MB)