Cuatro Ciénegas, Mexico, a living laboratory and a proxy for early Earth, shows living stromatolites in a pristine river system, targets of investigation for the VPL team to better understand microbial evolution and adaptive processes.
VPL modeling results predict that a planet's gravitational interaction with the parent star can create extreme volcanism and vaporize oceans
VPL researchers work to understand the co-evolution of photosynthesis with the planetary environment on planets that orbit stars very different to our Sun.

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VPL Headlines


Collisions could reveal “invisible gas” in exoplanets

VPL graduate student Edward Schwieterman, professor Victoria Meadows, and researchers Tyler Robinson, Amit Misra, and Shawn Domagal-Goldman have demonstrated that the collisional absorption signature of nitrogen gas can be detected in Earth’s disk-averaged spectrum and have modeled how it would appear on Earth-like exoplanets. Usually, nitrogen is considered an “invisible gas” because it lacks normal spectral features.  Detection of nitrogen would provide a means to characterize the bulk atmosphere of potentially habitable exoplanets and constrain the likelihood of oxygen production by non-living processes. The paper will be published in The Astrophysical Journal. MORE>


Atmospheric signs of volcanic activity could aid search for life

VPL graduate students Amit Misra, Josh Krissansen-Totton, Steve Sholes, and colleague have collaborated on an interdisciplinary paper on how to detect geological activity on extrasolar planets by looking for volcanically-induced transient sulfate aerosols in the planet's atmosphere. MORE>


Searching for Alien Biosignatures: Non-Photosynthetic Organisms May Produce Novel Signatures of Life on Exoplanets

VPL graduate student Edward Schwieterman, professor Victoria Meadows, and professor Charles Cockell at the UK Centre for Astrobiology present an interdisciplinary study of the possibility non-photosynthetic organisms may create signs of life on Earth-like exoplanets. These organisms contain pigments that reflect light differently than water, rocks, or photosynthetic organisms like land plants, producing spectral signatures that could indicate the presence of life. The paper was published in the May issue of Astrobiology.   MORE>


Earliest evidence for microbial nitrogen fixation at 3.2 billion years ago

VPL Researchers, led by NAI NPP postdoc Eva Stueeken, with colleagues Matt Koehler and Roger Buick analyzed 3.2 billion year old rocks from Australia and found the oldest record of life using atmospheric nitrogen to make organic chemicals. This discovery implies that the size of the early biosphere was not limited by nitrogen availability - a critical bottleneck for life - and that microbial life may have been quite abundant on the early Earth. The paper was recently published in "Nature".     MORE>


VPL Joins the NExSS Exoplanet Research Network

VPL is now a founding member of NASA’s new Nexus for Exoplanet System Science (NExSS) research network and is credited as being part of the inspiration for the the formation of this scientific "super group." NExSS encourages exoplanet research projects funded by the NASA Astrophysics and Planetary Sciences Divisions to collaborate in a strongly interdisciplinary way:   MORE>


Stars May Change Mini-Neptunes into Habitable Planets

VPL graduate student Rodrigo Luger, professors Rory Barnes and Victoria Meadows, and collaborators have found that some terrestrial planets in the habitable zones of low mass stars could be the evaporated cores of small Neptune-like planets. While these planets are likely to be very different from Earth in composition, they should have abundant surface water, one of the principal ingredients for habitability. The paper was published in the January issue of Astrobiology. MORE>


New Venus Studies Probe the Dynamic Atmosphere Below the Clouds and Reveal the Complexities of Hazy Worlds

VPL graduate student, Giada Arney, and VPL colleagues, present the first maps of cloud opacity, droplet sulfuric acid percentage, and trace gases in the Venus lower atmosphere.  Unexpected temporal and spatial variations of several species may be related to rainout processes, and variable hemispherical dichotomies suggest that the Venusian troposphere is just as dynamic as higher layers of the atmosphere.  There may be many Venus-like exoplanets, and understanding the planet next door is the first step to understanding these other worlds. MORE>


Too Hot To Handle: Planets in the Habitable Zones of Low Mass Stars May Be Roasted Early On

VPL graduate student Rodrigo Luger and Professor Rory Barnes have shown that many terrestrial planets in the habitable zones of low mass (M dwarf) stars could have experienced extreme stellar heating for up to 1 billion years after planet formation. This heating arises because M dwarfs evolve differently than the Sun -- they contract and cool for a much longer period of time. As they cool, the habitable zone moves in and so planets we find in the habitable zone today may have spent up to 1 billion years in a Venus-like state. During this period, destruction of water by UV radiation and hydrogen escape to space could ultimately build up massive abiotic oxygen atmospheres. MORE>


Earth's Glacial Cycles Might Be Influenced by Human Activity

Recent work by VPL researcher Jacob Haqq-Misra explores the long-term patterns in Earth's ice coverage resulting from changes in orbital geometry, and demonstrates that modern human activity could be capable of reducing or even stopping these glacial cycles completely. MORE>


VPL Featured in The Atlantic

An extended article in The Atlantic explores the current state of exoplanet research, and highlights the VPL's role in the search for Earth-like planets—featuring commentary by VPL researchers Victoria Meadows, Rory Barnes, and Nancy Kiang. MORE>


Sunsets on Titan Reveal the Complexity of Hazy Exoplanets

VPL postdoc Tyler Robinson and team have discovered that we can learn more about exoplanet atmospheres by observing sunsets on Saturn's moon, Titan. With observational data from NASA's Cassini spacecraft, they have used Titan as a proxy for a transiting exoplanet—finding that the presence of a hazy atmosphere may significantly restrict what we can learn about a world's potential habitability.   MORE>


First Earth-Sized Planet in the Habitable Zone Discovered

Today, VPL researcher Sean Raymond and collaborators announced their discovery of Kepler-186f. Located at the edge of its star's habitable zone, with a radius 1.1 times that of Earth's, it is arguably the most Earth-like planet found to date. MORE>


"Tilt-A-Worlds" Could Be Potentially Habitable

VPL researchers Rory Barnes, John Armstrong, et al. have determined that a fluctuating tilt in a planet's orbit does not preclude the possibility of life—a finding which may dramatically increase the number of known worlds thought to be potentially habitable. The paper was published in this month's issue of Astrobiology. MORE>


VPL Researchers Devise New Method for Understanding Exoplanet Atmospheres

A new method devised by VPL researchers makes use of "dimer molecules" to help determine pressure in exoplanetary atmospheres, and thus to better assess a planet's potential for habitability and life. The paper, headed by UWAB student Amit Misra, was published in this month's issue of Astrobiology and has been featured in a news article by Science magazine. MORE>


New Research Reveals Temperature Rule for Planetary Atmospheres

VPL researchers Tyler Robinson and David Catling have just published research in Nature Geoscience that reveals the reason for the atmospheric "tropopause"— a level in a planet's atmosphere between the troposphere and stratosphere where the air stops cooling and begins growing warmer. In their paper, Robinson and Catling explain that this effect is likely caused by increased atmospheric transparency to thermal radiation at low pressures. With this knowledge, astronomers may be able to better determine an exoplanet's potential for habitability and life. MORE>


Greenhouse Gas May Explain Liquid Water on Early Mars

While the evidence for liquid water on early Mars is well established, researchers have been hard-pressed to explain how this might have happened, considering the sun was much fainter in the past than it is today. Now, Ramses Ramirez of Penn State and other VPL team members have shown that in addition to carbon dioxide and water vapor, Mars's ancient atmosphere could have also contained just enough hydrogen to create a strong greenhouse effect, raising temperatures enough to allow for liquid water on the planet's surface. MORE>


New Estimates for the Probability of a Runaway Greenhouse

Whether a planet is able to avoid a "runaway greenhouse" fate strongly depends on how close it is to the inner edge of its star's habitable zone. New work by VPL researchers shows that less thermal radiation may be required for a planet to trigger this process than was previously thought. This suggests that the habitable zone could be narrower than we think, and that planets must be further from their stars to be considered hospitable for life.   MORE>


Natural Affinity May Have Facilitated the Formation of Protocells

New research by Prof. Sarah Keller and Dr. Roy Black (UW) suggests that the joining of RNA and fatty acids to form the first cells may have been assisted by a natural affinity between these components. Their results show that the four bases found in RNA bind more easily to decanoic acid (a fatty acid representative of those present on Earth before life began) when compared to other bases. MORE>


Research Shows "Snowball" Planets Are Less Likely Around Cooler Stars

UW graduate student Aomawa Shields, along with a team of other VPL researchers, has recently published research arguing that planets orbiting cooler stars are less likely to turn into icy "snowball" worlds. The explanation behind this apparent paradox is that cool stars emit more longer-wavelength, near-infrared light, which is readily absorbed by a planet, heating it up. By comparison, hot stars emit more high-energy visible and UV light. If a planet is already icy, it will easily reflect these wavelengths, cooling the planet and leading to more ice, in a cycle called "ice-albedo feedback". Shield's research will be released in the August issue of Astrobiology. MORE>


VPL Researcher Finds Three New 'Super-Earths' in the Habitable Zone

UW Astronomer Rory Barnes, along with a team of international collaborators, have just announced their discovery of three potentially-habitable 'super-Earth' planets orbiting the nearby GJ667C, a red dwarf star only 22 light years from Earth. While the star had previously been known to host two planets, these new observations bring the total number of confirmed planets in the system to six, with an unconfirmed seventh. “Instead of observing 10 stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them,” Barnes says. MORE>


VPL Researcher Eric Agol Discovers Most Earth-like Exoplanet to Date

In the latest discovery from the Kepler Space Telescope, VPL researcher and University of Washington astronomer Eric Agol has identified Kepler-62f: an exoplanet in its star's habitable zone, with a radius only 40% larger than Earth— making it the smallest potentially habitable exoplanet found to date. Kepler-62f has an orbital period of 267 days, and belongs to a multi-planet system orbiting a K2 dwarf star roughly 1200 light years from Earth. Although Kepler's mass and density have not been measured, it is likely to have a rocky composition.  MORE>


VPL Researcher Rory Barnes's work on Exomoons Featured in Astrobiology

Research by the VPL's Rory Barnes has been featured as the cover story in the latest issue of Astrobiology! In the paper "Exomoon Habitability Constrained by Illumination and Tidal Heating", Barnes explores the effects that physical and orbital parameters may have on the habitability of "exomoons", or moons belonging to exoplanets-- which it may now be feasible to detect.   MORE>


UWAB Graduate Student Explores Life at High Altitudes

While studies have previously discovered microbes living in the upper atmosphere, new research by UWAB graduate student David Smith aims to better understand the types of microorganisms present at high altitudes, how they get there, and how they're able to survive in such an extreme environment.  MORE>


How the Land Was Won 2.75 Billion Years Ago: New UWAB/VPL Research

New research by UWAB student and VPL team member Eva Stüeken suggests that microbes might have been widespread on Earth's surface around 2.75 billion years ago, where they produced oxygen and weathered pyrite, an iron sulfide mineral, which released sulfur and molybdenum into the oceans. In turn, this sulfur likely enhanced the spread of marine life. To learn more, check out the story in UW News. MORE>


VPL Researchers Explore The Sun's History

In a paper recently published in The Astrophysical Journal, VPL team members Mark Claire, John Sheets, Martin Cohen, Victoria Meadows, and David Catling model wavelength-dependent changes in the solar flux over geologic time. Understanding these changes is crucial for understanding the evolution of planetary atmospheres and climates, and thus planetary habitability. The model described in the paper is available here, and is valid for the zero-age main sequence to 8 Gyr. MORE>