EAI Academy 2021-2022 – CAB

EAI ACADEMY 2021-2022

The EAI ACADEMY is a new international educational program that has been broadcasted during the 2021-2022 academic year by the Center for Astrobiology (CAB), Madrid.

The Academy offers for each academic year, and free of charge, 16 online seminars on topics related to astrobiology. These online events have been very popular: the program has 350 subscriptors and each seminar has had between 200 and 80 attendees from 32 countries and all continents. The talks are given by world-renowned experts, who answer the questions raised by the public after their talk. At the end of the academic year, CAB awards a certificate of participation to those who attend at least 10 seminars and the University of Tartu awards 3 ECTS and a digitally stamped certificate to those who also complete a short homework assignment. All past seminars have been recorded and are available on the CAB youtube channel.

The program, which has been a success, will be relaunched in September for the 2022-2023 academic year. The announcement of the program and the indications about how to subscribe will be posted here and released to the current email distribution list in due time.

For more information about the program, future announcements and to access the recording of the past conferences please check on this web page.

Armando Azua-Bustos

Planetology & Habitability Dpt.
CAB (Spain)

October 13th, 2021

Is Mars too dry for life as we know it?

All life on Earth is based on water, explaining why on Mars, we search for water as a proxy for life. In this talk, I will share my findings on how life has adapted to the extreme environmental conditions of the Atacama Desert, by far the driest and oldest desert on Earth, and what can this tell us about where to look for life on the red planet.

Hunter Waite

South West Research Institute (USA)

October 27th, 2021

What we learned about Enceladus using Cassini Mass Spectrometry

The Cassini-Huygens mission had two mass spectrometers onboard the Cassini orbiter - the Ion Neutral Mass Spectrometry and the Cosmic Dust Analyzer. This talk will concentrate on how mass spectrometry measurements from these two instruments helped to verify the existence of an ocean at Enceladus and provided insight into the geochemistry of the internal ocean. The talk will also look forward to the NASA Clipper mission to Europa and indicate how what we learned from Cassini at Enceladus is being applied to the Clipper mission.

David Barrado Navascués

Astrophysics Dpt.
CAB (Spain)

November 10th, 2021

Planetary systems beyond the Solar System

We know 4864 planets in 3595 planetary systems, reveled by different techniques during the last three decades. This very diverse population includes new types not found in the solar system and essentially we can conclude that almost any star has a planetary system, at least for solar-type and cooler stars. However, many questions need an answer, among them: What is the origin of the observed exoplanet diversity? How and where did exoplanets form? What are they made of? What planetary architectures can we find? What are their atmospheric properties? Are the atmospheric composition and temperature indicative of an environment which could host life? In this talk these topics will be described and some of the most impressive results will be shown.

Tilman Spohn

ISSI/DLR (Switzerland/Germany)

November 24th, 2021

Could Earth have Desert and Ocean Planet Siblings with Plate Tectonics?

It is widely accepted that plate tectonics is an important element of Earth’s habitability. After all, plate tectonics is an important element of the long-term carbonate silicate cycle stabilizing the climate, renews crustal rock as the basis for the food chain and its heat transfer efficiency helps to produce a magnetic field by dynamo action in the core. Moreover, the continental crust as we know it is a result of plate tectonics with land and shelf areas providing easy access to solar energy and the oceans a huge water reservoir. But is the about equal surface distribution between oceans and continents a necessary outcome of the evolution of a plate tectonics planet? By considering an evolution model with continental growth, water and CO2 cycle and cooling, we find that depending on parameter and initial values, there may be three outcomes rather than just one. In addition to an Earth-like surface, a planet mostly covered by continents may result as well as a planet covered almost entirely by oceans - the latter resembling Venus after loosing all its water. Choosing random combinations of initial conditions, we find the land planet to be the most likely outcome followed - with distance - by the ocean planet and the Earth-like planet the least likely. We speculate that both the continent and the ocean planet would be less life-supporting than Earth.

Giovanni Vladilo

INAF- Trieste Astronomical Observatory (Italy)

December 8th, 2021

Defining exoplanetary habitability: climate models and hydrogen-bond criteria

The search for atmospheric biosignatures in exoplanets is one of the most challenging tasks of observational astronomy. This endeavour needs to be supported by models able to estimate the habitability of the planet and the detectability of spectroscopic signatures from a sparse set of observational data. In this context, I will present an approach aimed at quantifying the planetary habitability according to the surface distribution of physical quantities that affect life processes, such as the temperature or ionizing radiation. The seasonal and latitudinal distribution of surface temperature can be calculated with the aid of climate models tailored to cover a broad palette of stellar, orbital and planetary properties. With this approach, the remote search for life in exoplanets can be narrowed by selecting targets characterized by surface conditions that maximize the production and detectability of atmospheric biosignatures. In the final part of my talk, I will scrutinize the universality of the liquid-water criterion of habitability, which is based on the properties of terrestrial biochemistry. Assuming that life processes require an active network of inter/intra-molecular interactions, I argue that it is possible to rank the viability of hypothetical, alternative biochemistries according to the hydrogen-bond capabilities of their molecular constituents. This approach suggests that the liquid-water criterion is probably the most appropriate in the search for any form of life that has emerged from spontaneous chemical pathways.

José A. Caballero

Astrophysics Department
CAB (Spain)

January 12th, 2022

Exoplanet biomarkers

I will not talk on biomarkers in Solar System bodies. I will not explore exotic habitable regions in exoplanets (e.g. subsurfaces of icy planets, upper atmospheres of gaseous giants). Instead, I will focus on the tools and techniques for discovering combinations of biomarker candidates in the atmospheres of telluric planets in the standard habitable zone. How to do it? Which stars to look at? Which planets? Which facilities to use? My talk will not be an ecncyclopaedia, but a "hitchhiker guide to future exoplanetologists".

Victor Rivilla

Astrophysics Department
CAB (Spain)

January 26th, 2022

The Pathway to Prebiotic Chemistry: molecular precursors from space

We still do not understand how simple molecules combine together to form large molecules essential for living organisms. Recent prebiotic experiments, based on the RNA-world hypothesis for the origin of Life, have suggested that the three basic macromolecular systems (nucleic acids, proteins and lipids) could have formed from relatively simple precursors. The detection of some of these molecules in space, thanks to the unprecedented capabilities of current astronomical ground-based and space facilities, has opened a new window for astrobiology from the astrochemical point of view. A deep understanding of the chemical reservoir of the different phases of star formation is crucial to understand how Life could have appeared starting from simple molecular precursors. In this seminar I will present an overview of the most recent results of our search in space of key molecular precursors of the RNA-world. Using data from ultradeep spectra surveys carried out with radio and (sub)millimeter telescopes and space missions, we have revealed the presence of more than 10 new molecules in the interstellar medium and in the comet 67P/Churyumov-Gerasimenko, which are direct precursors of nucleic acids, proteins, lipids, and phosphorus-bearing molecules. This amazing chemical complexity, which might be only the tip of the iceberg, means that interstellar chemistry offers an extremely rich feedstock for triggering prebiotic chemistry.

Diana E. Northup

Biology Department
University of New Mexico (USA)

March 9th, 2022

The Hidden Microbial Life in Earth’s Lava Caves: Implications for Life Detection on Extraterrestrial Bodies

Earth’s caves provide valuable analogues for exploring best targets for life detection on extraterrestrial bodies. Microorganisms in Earth’s lava caves create a variety of visible features that range from secondary mineral deposits to microbial mats and ooze that occur on cave surfaces. We are investigating whether secondary mineral shape, texture, and vertical heterogeneity would be predictive of the extent of potential microbial content and microbial diversity. Our goal is to assess the microbial content of lava cave secondary mineral deposits in comparison to microbial mats. Our research will shed light on the best targets for robotic missions to extraterrestrial bodies.

Amri Wandel

University of Jerusalem (Israel)

March 23rd, 2022

Liquid water on Exoplanets and the Habitable Zone

Finding extra-terrestrial planets that may support life is one of the biggest goals in astronomy. Since life as we know it evolved and survives in water, the major requirement for finding worlds potentially suitable for life is liquid water. We define planets that could support life by determining whether they lie in the ‘habitable zone’ of their parent star – an annular region in which liquid water might exist on the planetary surface. A planet too close to its star would be too hot, so any liquid water would evaporate, while a planet too far away would be too cold, and water would freeze. Of course, life could exist on planets or moons with subsurface liquid water, such as Europa in our Solar System, but it would be more difficult to detect on exoplanets, hence it is of less interest to astrobiologists.

Jan Amend

University of Southern California (USA)

April 6th, 2022

The marine deep-subsurface biosphere

The subsurface biosphere on Earth is extensive, diverse, and still largely unexplored. Since 2010 I have led C-DEBI, an NSF-funded Science and Technology Center established to better understand the microorganisms that inhabit the sediment, rock, and fluid in the marine subsurface. Our approaches combine field-based research with laboratory studies of microbial survival and propagation, and modeling studies of physico-chemical properties and redox reaction energetics. I will highlight some of the team’s most exciting findings from the three major field sites: the Juan de Fuca ridge flank hydrothermal system, the oligotrophic sediments of the South Pacific Gyre, and an isolated sediment pond (‘North Pond’) and underlying basement on the western flank of the Mid-Atlantic Ridge. I’ll finish with some modeling studies, first on global sediment budgets and properties and second on predicting novel microbial catabolisms.

Anna Neubeck

Uppsala University (Sweden)

April 20th, 2022

Hydrothermal systems - life in the dark

Hydrothermal systems are systems in which hot water is circulating within the oceanic or continental crust, releasing energy, mass and nutrients. These circulating hot fluids provide gradients (composition, temperature, pH etc) suitable for sustaining life in and surrounding hydrothermal vents. It was not until the 1960´s that the deep marine hydrothermal vent systems were discovered and unfolded an entirely new viewpoint on plate tectonics and life. After this discovery, hundreds of new species have been described and still today, new species are detected around hydrothermal vents. Symbiosis, chemosynthesis, prebiotic chemistry and marine biogeochemical cycles are some of the topics that greatly expanded after the detection of hydrothermal vents, that have also led to new ideas on life and habitability elsewhere than Earth.

Olivier Mousis

Aix-Marseille Université (France)

May 4th, 2022

From the thermodynamic evolution of the protosolar nebula to the present-day composition of Jupiter

Recently, the microwave radiometer aboard the Juno spacecraft provided a measurement of the water abundance in the equatorial region of Jupiter, from 0 to 4 degrees of north latitude, and in the 0.7-30 bar pressure domain. The water abundance in this region of Jupiter was found to range between 1 and 5 times the protosolar abundance of oxygen, a value substantially higher than the previous Galileo probe determination. Here, we aim to combine this up-to-date oxygen determination with the other known measurements of elemental abundances in Jupiter, to discuss the mechanisms that could explain the supersolar metallicity of its envelope. We find that the supersolar metallicity of Jupiter’s envelope can be both explained by the agglomeration of solids condensed in the giant planet’s feeding zone and by the accretion of supersolar gas during its growth. Our study illustrates the importance of measuring the elemental abundances in the giant planets atmospheres, as they can be used to trace the planetary formation location and/or the chemical and physical conditions of the protosolar nebula.

Charity Philips-Lander

South West Research Institute (USA)

May 11th, 2022

Searching for evidence of life on subterranean Mars: Prospects and Challenges

The subsurface of Mars remained habitable long after surface conditions deteriorated for life, and may remain habitable to this day. Accessing the subsurface is challenging, as evidenced by the challenges encountered with the Insight Mission’s drilling operation. One way to explore Mars’ subsurface is through planetary caves. Over 1000 potential cave entrances exist on Mars. Recent work has linked some of these observed cave entrances to laterally extensive lava tubes that may serve as preferential water conduits, provide radiation attenuation, and relatively stable climate conditions, which would make them targets for future cave astrobiology missions as well as potential habitats for future astronauts. While several cave mission concepts have be proposed, subsurface exploration remains technologically challenging. Both science and engineering must come together to make a future planetary cave mission viable and successful. In this seminar I will present an overview of the current state of the science, engineering, which are essential components to cave mission development and ultimately, mission selection.

Doris Breuer

Institute of Planetary Research, DLR (Germany)

May 18th, 2022

The habitability of Mars: a geophysical approach

Mars is one of the planets in our solar system that may have had habitable conditions (or may even still be habitable below the surface today), as various evidence points to the existence of liquid surface water in its early history. The habitability of a planet is influenced by several factors, in addition to the planet's distance from the Sun, also by its composition and atmosphere, as well as its tectonic system. In this talk, I will focus on the initial conditions after planet formation and the magma-ocean phase, and address the question of whether water was initially present in planet’s interior or in the atmosphere and on its surface. I will also discuss the internal dynamics and exchanges between the planet's interior and atmosphere. Mars is a single-plate or so-called stagnant-lid planet, which means that mantle convection occurs beneath a solid lithosphere and the exchange of volatiles such as water and CO2 occurs essentially through volcanism in a one-way process from the interior to the atmosphere and surface. These processes are described and the extent to which they contribute to the habitability of the planet is discussed.

Victor Parro

Molecular Evolution Dpt.
CAB (Spain)

June 1st, 2022

Life inside the rocks: microbial diversity and metabolisms in the deep subsurface

Bioavalable water is essential for life, as well as the appropriate refuge to escape from harmful radiation, abrasive winds or currents, predators, or for buffering temperature. Microbial life exhibit several strategies for that, from the production of protective pigments and biofilms to conquest of new niches which provide shelter and mild conditions. This is the case for those adapted for living inside solid matrices such as rocks, minerals, or even ice. These strategies are essential to understand and assess the feasibility of life in other planetary bodies. With the increasing number of exoplanets detected, and much more to come, astronomers look for rocky planets falling in the habitable zone that allow them with abundant liquid water in its surface. But life not necessarily need oceans to thrive. On Earth, more than 70% of prokaryotes (Bacteria and Archaea) live in the deep subsurface (continental and oceanic), most of them in tight association with rocks and minerals. I will review some of the key features of microorganisms living insight deep subsurface rocks, the both from literature and our own research, as well as discuss how they can condition the search for life in other planets.

Olga Prieto-Ballesteros

Planetology & Habitability Dpt.
CAB (Spain)

June 8th, 2022

Deciphering Ocean Worlds in the lab

Because there is no way to directly observe or measure planetary processes occurring in the interior of ice moons so far, we rely on experimental studies in the laboratory to determine quantitative values and relationships of geochemical/geophysical parameters in order to construct models of the deep environments (e.g. structure, composition, activity, habitability). Information from experimental studies will help to interpret observations of the coming space missions to these planetary objects to achieve astrobiology science objectives.