SETI Institute Weekly Colloquium
At the Microsoft Campus in Mountain view
1065 La Avenida St, Mountain View CA
FREE and open to the public. Tuesdays, noon to 1pm
It is widely accepted that the occurrence of methane (CH4) in the Martian atmosphere may imply the presence of active geological sources, i.e. gas emission structures in the Martian soil and subsoil. In other words, gas seepage, a process well known on Earth, should exist on Mars. The concept of gas seepage,although obvious for many geologists, especially those working in gas geochemistry and petroleum geology, is ignored or poorly known by Mars methane science community. The seminar will offer a discussion on the fundamentals of seepage, its potential occurrence on Mars (via microseepage, mud volcanoes, faults, degassing from serpentinized rocks) and possible detection techniques. Basic concepts on potential methane origin on Mars (biotic vs abiotic) will be discussed and clarified, considering some confusion and misinterpretations in present literature.
Giuseppe Etiopeis a senior researcher, geologist, at the Istituto Nazionale di Geofisica e Vulcanologia in Rome, Italy. He works on the origin, occurrence, and migration of gas in the geosphere, with particular reference to biotic hydrocarbons in sedimentary basins and abiotic gas in serpentinized ultramafic rocks. He studies the origin of methane, gas seepage phenomena and their implications for the environment, energy resource exploration and planetary geology (methane on Mars). He published 164 articles and a Springer’s book on “Natural Gas Seepage”. H index: 27 (Web of Science); 32 (Google Scholar).
Dwarf galaxies tend to form stars inefficiently. Yet, blue compact dwarf (BCD) galaxies are a subset of dwarf galaxies that have intense and concentrated star formation (compared to typical dwarf galaxies). BCDs are thought to require a large disturbance to trigger their burst of star formation. A common theory is that the enhanced star formation in a BCD is the result of an interaction with another galaxy or a dwarf-dwarf galaxy merger. However, many BCDs are relatively isolated from other galaxies, making an interaction or a merger a less likely starburst trigger.
As part of the atomic hydrogen dwarf galaxy survey, LITTLE THINGS*, Dr. Ashley has studied the gaseous properties of six BCDs. Atomic hydrogen data allow us to explore the velocity fields and morphologies of the gas in BCDs, which may contain signatures of star formation triggers, such as gas consumption, a past merger, and interaction with previously undetected companions. If BCDs have formed through gas consumption or dwarf-dwarf mergers, then they would be useful analogs for galaxy formation in the early universe. Also, learning which large disturbance has triggered the burst of star formation in BCDs could be useful for understanding and modeling how/whether BCDs evolve into/from other types of dwarf galaxies.
In the last few years we have found that Mars' south polar cap has as much carbon-dioxide as Mars' current atmosphere. This raises numerous questions about how this massive deposit formed and what Mars was like when it was in the atmosphere. Using a combination of methods including spacecraft imagery, radar, and modeling we can start to answer some of these questions. Carver Bierson will discuss evidence that these deposits may have formed over several cycles of Mars atmosphere collapsing onto the surface and then sublimating back into the atmosphere.