Astrobiology

Earth-Sized Planets in the Habitable Zones of Cool Stars

Abstract: A primary goal of the Kepler mission is to determine the frequency of Earth-sized planets in the habitable zones of other stars. M dwarfs, stars that are smaller and cooler than the Sun, comprise more than 70% of the stars in our galaxy. Finding that Earth-sized planets around M dwarfs are common, therefore, has big implications for determining the frequency of other Earths.

Why SuperEarths are not Earthlike

Kepler data indicate that there are many planets that could be Earthlike in the sense of having a similar bulk composition. I will explain why such planets are unlikely to be Earthlike in other respects, especially if they are superEarths (three or so Earth masses or more). There are three main points here: (1) SuperEarths will not separate core from mantle because they are likely to be so hot internally that the critical temperature is reached for miscibility of iron alloy and silicate material.

Every Body is an Ark: How the microorganisms we carry will impact long term space travel

germsThe human microbiome is essential to our health and deserves special consideration in the closed environments of space travel. The dynamics of host-microbe interactions will change if normal immune functions are altered during extended space travel. Opportunistic pathogens common in the human microbiome, including those in the genera Candida, Aspergillus, and Staphylococcus, could spread among crewmembers and put them at risk of serious disease.

Refactoring Space Exploration with Soft Machines

T12 robotTo understand how we control motion, we need to understand the physical mechanism being moved. Emerging theories of vertebrate physiology are overturning the traditional bone-centric model of the body in favor of a "tensegrity" model, in which the primary load paths are in the continuous tension network of the soft tissues.

Life before genetics: autogenesis, information, and the outer solar system

moon of giant gas planetThe investigation of the origins of life has been hindered by what we think we know about current living organisms. This includes three assumptions about necessary conditions: 1) that it emerged entirely on Earth, 2) that it is dependent on the availability of liquid water, and 3) that it is coextensive with the emergence of molecules able to replicate themselves.

Engineering the emergence of life through convection, serpentinization and the first metabolic pathway

mike russel in labThe alkaline hydrothermal theory for the emergence of life holds that the endergonic (thermodynamically uphill) reactions vital for life’s origin and continued existence require free energy converters (nano-engines) fuelled by various disequilibria.

Characterizing the Atmospheres of Low-Mass Low-Density Transiting Exoplanets

exoplanetNASA's Kepler Mission has revealed that the most common size of planet in our galaxy may be those from 2-3 Earth radii.  Such medium-sized planets are significantly more common on close-in orbits than Neptune and Jupiter-class giant planets.  We have no analog for these planets in our solar system.  What are they made of?  An example relatively close to home is planet GJ 1214b, which is 2.6 Earth radii and 6 Earth mass

Planetary Lake Lander

Deglaciation subjects lakes to interannual variability, affecting lake habitat, biogeochemical cycles, and biodiversity. Investigating its impact contributes to a better understanding of the changes currently affecting Earth's glacial lake ecosystems. From an astrobiology perspective, it may bring new insights into the evolution of Mars habitability during comparable geological periods.

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