Welcome to Astrobiology at the University of Washington
The unusual architecture of the υ Andromedae planetary system
The star υ Andromedae has 3 known planets orbiting it, all three close to or greater than the size of Jupiter. Surprisingly, observations show that the orbits of the outer two planets are tilted relative to each other by about 30 degrees, which is very unusual in comparison with the solar system. A study led by UWAB graduate student Russell Deitrick together with Prof. Rory Barnes, Prof. Tom Quinn, and Rodrigo Luger used computer models to learn more about this interesting planetary system. The researchers were able to place constraints on the inner-most planet's mass and orbital tilt, which were previously unknown. They found that the inner-most planet is likely to be several Jupiter masses, and its orbital plane is probably aligned about halfway between the planes of the outer two planets. MORE>
Is the pale blue dot unique?
Voyager 1's iconic image of the Pale Blue Dot shows hints of Earth's uniqueness are visible from great distances; the pale blue color of Earth sets it apart from other objects in our Solar System. But could planet color be used to easily identify Earth-like exoplanets? UWAB graduate students Joshua Krissansen-Totton, Edward Schwieterman, Giada Arney, former VPL grad student Tyler Robinson, postdoc Benjamin Charnay, Professosr Victoria Meadows, and David Catling have authored a paper on whether color can be used to distinguish Earth-like exoplanets from uninhabitable worlds. This paper shows that numerous uninhabitable planets - particularly icy worlds with thick atmospheres - could mimic the Earth's pale blue color. It is possible to distinguish these icy worlds from Earth-like planets with extremely precise color observations, but this level precision demands a lot of telescope time. This suggests that spectral observations may be preferable to color observations for identifying Earth-like exoplanets. MORE>
UWAB Fall 2015 Newsletter Released
The UWAB Fall 2015 newsletter is out! Check it out to get the latest information on our program! MORE>
Where to look for life?
UWAB astronomers Rory Barnes, Victoria Meadows, and research assistant Nicole Evans have co-authored a paper on how to prioritize targets in the search for life beyond our solar system. We know of over 3000 exoplanets now, and we'll discover many more in the coming years. To quote Rory: "Now it's as if Goldilocks has hundreds of bowls of porridge to choose from!" Which ones should we focus on precious telescope observing time on? A new metric called the "habitability index for transiting planets" ranks worlds according to a suite of properties that impact how life-friendly a planet is likely to be. MORE>
Collisions Could Reveal "Invisible Gas" In Exoplanets
UWAB 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 has been published in The Astrophysical Journal here. MORE>
Atmospheric signs of volcanic activity could aid search for life
UW Astrobiology graduate students Amit Misra, Josh Krissansen-Totton, Matt Koehler and Steve Sholes 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>
Beyond Human: Animals, Aliens, and Artificial Intelligence!
UWAB and Museology graduate student, Wolf Clifton, has launched his Masters project which is an online exhibit titled "Beyond Human: Animals, Aliens, and Artificial Intelligence!" MORE>
Searching for Alien Biosignatures: Non-Photosynthetic Organisms May Produce Novel Signatures of Life on Exoplanets
UWAB 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 resulted from an Astrobiology Program research rotation and was published in the May issue of Astrobiology. MORE>
Stars May Change Mini-Neptunes into Habitable Planets
UWAB 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
UWAB 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>