Welcome to Astrobiology at the University of Washington
UWAB Outreach to Lakewood High School
On May 2, continuing an annual tradiation, UWAB members spoke to students in an astrobiology class at Lakewood High School visiting UW. Professor Rory Barnes led the event, which featured presentations by UWAB students Michael Kipp, Giada Arney, Steven Sholes, and Jacyln Sanders. MORE>
Early earth's air pressure was less than half of today's
A new study led by UWAB alum Sanjoy Som together with UWAB professors Roger Buick and David Catling and others implies that early Earth's atmospheric pressure 2.7 billion years ago was less than half of modern day. The researchers used gas bubbles trapped in ancient sea-level lava flows as a "paleobarometer". The sizes of the bubbles record the pressure of the atmosphere bearing down on the cooling lava billions of years ago. This low atmospheric pressure suggests that early microbes may have been consuming atmospheric nitrogen, but there was not an efficient process to release that consumed nitrogen back to the atmosphere like there is today. MORE>
Congratulations to Rory Barnes!
Rory Barnes of the astronomy department has been promoted to an Assistant Professor in astrobiology! Congratulations Rory! MORE>
Congratulations to UWAB members helping select the next NASA flagship mission!
NASA has convened Science and Technology Definitions Teams (STDTs) to study large telescope concepts for future direct imaging of exoplanets. Congratulations to UWAB Chair Vikki Meadows, UWAB PhD graduate Tyler Robinson, and UWAB former postdoc Shawn Domagal-Goldman who have been seletected as members of these teams! Vikki will be a member of the LUVIOR team, and Shawn will be the LUVIOR Deputy Study Scientist. Shawn is also a member of the HabEx STDT, as is Ty Robinson. Congratulations to all! MORE>
Hints from selenium isotopes on the end-Permian mass extinction
UWAB postdoc Eva Stüeken, Professor Roger Buick, and collabors studied isotope ratios of selenium, a trace element. Their results show that biological productivity of macro-organisms collapsed during the Permian-Triassic mass extinction, but the collapse was probably not caused by a shortage of nutrients. Other factors such as ocean acidification or perturbations of food webs may have been more important. MORE>
Congratulations to Aomawa Shields!
UWAB alum Aomawa Shields (astronomy and astrobiology, 2014) has been awarded the 2016 ASU Origins Project Postdoctoral Lectureship Award! This prestigous $10,000 award is offered to young scientists based on scholarly achievement and skills in science communication. Shields, who has a professional acting background in addition to her rigorous training as a scientist, will be resident at Arizona State University for a week and will offer a series of departmental colloquia and a large public lecture in early April. Congratulations Aomawa! MORE>
A whiff of ancient oxygen supported by selenium isotopes
UWAB Postdoc Eva Stüeken, Professor Roger Buick, and collaborators showed that there was a brief interval around 2.5 billion years ago when the flux of selenium into the ocean increased and isotopes were more fractionated. These data support previous indications that this period corresponds to a brief "whiff" of free oxygen, either globally or within microbial mats on land. Hence oxygen production must have started long before the great oxidation event at ~2.3-2.4 billion years ago, which in turn supports the idea that it takes a considerable amount of time to fully oxidize the surface of a planet, which has implications for the evolution of organisms that require oxygen to breathe. MORE>
Congratulations to UWAB alumni!
Congratulations to two UWAB graduates on their new faculity positions! UWAB graduate Dr. Aomawa Shields (astronomy and astrobiology 2014) will be an Assistant Professor in the Department of Physics and Astronomy at UC Irvine. Dr. Rika Anderson (oceanography and astrobiology 2013) has been awarded an appointment as an Assistant Professor at Carleton College. Congratulations to both! MORE>
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>