CAB Seminar on Thursday 27th of November at 12:00 (CET) by María-Paz Zorzano (CAB)
Laura Colzi
CAB
SEMINARS
Thursday, 27th November 2025, 12:00 (CET) (Auditorio/Zoom)
The
Curiosity rover’s detection of organic
carbon and simple organic molecules in
3.5-billion-year-old sedimentary rocks
at Gale Crater, Mars, has opened
fundamental questions about the
long-term preservation of biomolecules
under Martian surface conditions.
Analyses indicate that these rocks
remained buried for most of their
geological history and have been exposed
to cosmic radiation only within the last
78 million years. If Mars was once
habitable, could DNA—or similarly
complex information-bearing
polymers—survive such an environment?
In this talk we will share our most
recent research around biomarker
preservation on Mars. We analyzed
analogous sedimentary rocks from Earth,
with organic carbon contents comparable
to those detected by Curiosity on Mars.
These rocks host distinctive microbiomes
that can metabolize organic carbon or
exploit redox-active minerals for
energy. Samples were subjected to
extreme gamma radiation doses equivalent
to more than 100 million years of
exposure on the Martian surface. Using
only 0.5 g of material per sample, we
extracted and sequenced hundreds of
thousands of nucleobases in an ISO Level
5 cleanroom to prevent contamination.
Despite fragmentation and nucleobase
damage 1.48–8.45% of sequences remained
taxonomically identifiable,
demonstrating that information-bearing
DNA fragments can persist in rocks for
over 100 Ma. This result can change our
current approach to the search for life
on Mars.
Join zoom meeting at: https://rediris.zoom.us/j/85134397594?pwd=Sms4OUdSWmdocGh3R1dwU1NJaWk2Zz09
Meeting ID: 851 3439 7594
Passcode: 125143
Previous seminars can be found at CAB YouTube channel: https://www.youtube.com/c/CentrodeAstrobiologia
A full list of seminars in our webpage: https://cab.inta-csic.es/formacion/seminarios