February 01, 2023
Those worlds, like Earth, are both rocky and found in their stars' habitable zones—where life as we know it could plausibly evolve and might produce atmospheric gasses that could be detected using space telescopes.
"As the research community has come up with models for abiotic origins of gases that could mimic biosignatures, we've really focused on source processes that could operate on Earth-like worlds," says Kite. "However, habitable-zone rocky exoplanets could have compositions and processes dramatically different from Earth. We want to consider a wider range of possible abiotic methane sources to make sure we don't get fooled by 'trickster' planets that emit false positive biosignatures."
"We don’t know much about the origin of life nor about how life is distributed in the universe," says Kite. "If the scientific community is to make a claim that alien life has been discovered through biosignature detection, it is our responsibility to ensure that we've thought long and hard about all the ways biosignatures could in fact be abiotic geosignatures."
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January 26, 2023
Alya Al-Kibbi, a first-year graduate student in the Department of the Geophysical Sciences, has been awarded a graduate fellowship from The Illinois Space Grant Consortium (ISGC). The award supports outstanding graduate students pursuing aerospace, astrophysics, astronomy, cosmology, Earth system science and other interdisciplinary space-related science, engineering, or mathematics fields.
Al-Kibbi was born in Washington, DC, and raised between there and Lebanon. She attended Caltech for undergraduate. As a planetary science student, she plans to research the role that comets play in the formation of planets in the solar system, and how comets can influence the current day compositions of these planets.
She will receive $10,000 towards research that contributes to furthering NASA’s science goals. “I intend to use the award to fund travel to conferences and expand my scientific perspective, and hopefully to help with the cost of publication of my research down the line,” she said.
According to Alya’s advisor, Prof. Fred Ciesla from the Department of the Geophysical Sciences, this is a unique and well-deserved opportunity. “I am very happy for Alya; she is very deserving!” he said. “This gives her a bit of extra flexibility to explore the field as she narrows down the focus of her research. To get this opportunity right at the start of graduate school is fantastic.”
For Al-Kibbi, this fellowship represents a first and strong step towards the development of her scientific career: “I was so excited to have been selected. As a first-year graduate student, I had very little confidence in my application compared to more experienced scientists. I am extremely grateful to have this opportunity to jump start my scientific career.”
December 05, 2022
For a long time, we didn’t know very much about the weather in the Southern Hemisphere: most of the ways we observe weather are land-based, and the Southern Hemisphere has much more ocean than the Northern Hemisphere does.
But with the advent of satellite-based global observing in the 1980s, we could quantify just how extreme the difference was. The Southern Hemisphere has a stronger jet stream and more intense weather events.
“You can’t put the Earth in a jar,” Professor Tiffany Shaw explained, “so instead we use climate models built on the laws of physics and run experiments to test our hypotheses.”
Shaw, graduate student Osamu Miyawaki (now at the National Center for Atmospheric Research), and colleagues used a numerical model of Earth’s climate built on the laws of physics that reproduced the observations. Then they removed different variables one at a time, and quantified each one’s impact on storminess. Shaw and her colleagues found two major culprits: ocean circulation and the large mountain ranges in the Northern Hemisphere. The study also found that this storminess asymmetry has increased since the beginning of the satellite era in the 1980s. The increase was shown to be qualitatively consistent with climate change forecasts from physics-based models.
The results have been published in the Proceedings of the National Academy of Sciences.