Chemical Timescales in the Atmospheres of Highly Eccentric Exoplanets

Close-in exoplanets with highly eccentric orbits are subject to large variations in incoming stellar flux between periapse and apoapse. These variations may lead to large swings in atmospheric temperature, which in turn may cause changes in the chemistry of the atmosphere from higher CO abundances at periapse to higher CH4 abundances at apoapse. Here we examine chemical timescales for COCH4 interconversion compared to orbital timescales and vertical mixing timescales for the highly eccentric exoplanets HAT-P-2b and CoRoT-10b. As exoplanet atmospheres cool, the chemical timescales for COCH4 tend to exceed orbital and/or vertical mixing timescales, leading to quenching. The relative roles of orbit-induced thermal quenching and vertical quenching depend upon mixing timescales relative to orbital timescales. For both HAT-P-2b and CoRoT-10b, vertical quenching will determine disequilibrium COCH4 chemistry at faster vertical mixing rates (Kzz > 10^7 cm^2 s^-1), whereas orbit-induced thermal quenching may play a significant role at slower mixing rates (Kzz < 10^7 cm^2 s^-1). The general abundance and chemical timescale results - calculated as a function of pressure, temperature, and metallicity - can be applied for different atmospheric profiles in order to estimate the quench level and disequilibrium abundances of CO and CH4 on hydrogen-dominated exoplanets. Observations of CO and CH4 on highly eccentric exoplanets may yield important clues to the chemical and dynamical properties of their atmospheres.Comment: 9 pages, 4 figures, accepted for publication in the Astrophysical Journal; v2 corrects typos and figure resolution issue

Against Common Sense

Scientific inquiry... allows for the exploration of phenomena that would otherwise remain beyond human intuition. Posting about ­­­­­­­­beauty and truth in creation from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/against-common-sense

The Shared Virtues of Science and Faith: A Review of Why Science and Faith Need Each Other

The reality is that areas of conflict and tension between science and religion do exist, even if the relationship is not defined by them. Posting about ­­­­­­­­the book Why Science and Faith Need Each Other from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/the-shared-virtues-of-science-and-faith-a-review-of-why-science-and-faith-need-each-other

Lunar Stories: The Violence of Creation

Tales of the moon’s creation abound in myth, legend, history and science. Given its conspicuous brightness and nearness, we should not be surprised that the moon has captured the imagination since the dawn of human consciousness. Posting about how the moon was made ­­­­­­­­from In All Things - an online hub committed to the claim that the life, death, and resurrection of Jesus Christ has implications for the entire world. http://inallthings.org/lunar-stories-the-violence-of-creation

Kuyper on Science: A Review of Calvinism for a Secular Age

Kuyper’s comprehensive vision for the Christian life has continued to capture a broader Christian imagination. Posting about the book Calvinism for a Secular Age from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/kuyper-on-science-a-review-of-calvinism-for-a-secular-age

The Making of Beautiful Things: A Review of Adorning the Dark

With a sacramental view of the world, we are pointed toward deeper creational truths that are accessible to all humans. Posting about ­­­­­­­­the book Adorning the Dark from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/the-making-of-beautiful-things-a-review-of-adorning-the-dark

Unsung Holiday: Earth Day

What can we do to pass on the gift of good land to our children and their children? Posting about our response to Earth Day from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/unsung-holiday-earth-day

Kinds of Science and Exploring the Past

Working alongside experimental and observational work, historical science helps us continue to learn the unfolding story of how a beautiful universe, created by a loving God, came to be as we see it today. Posting about scientific methods from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/kinds-of-science-and-exploring-the-past

Joy of Exploration

What drives our desire to turn pixels into portraits, and to turn distant specks of light into new worlds? Why does there exist such a strong, inherent human desire to explore the unknown, to see a part of creation that we haven’t seen before? Posting about the dwarf planet Pluto from In All Things - an online hub committed to the claim that the life, death, and resurrection of Jesus Christ has implications for the entire world. http://inallthings.org/gods-laughter-is-no-jok

All I Want for Christmas...

JWST [the James Webb Space Telescope] will let us see clearer and further into the ancient and beautiful story of creation. Posting about new developments in spacecraft from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/all-i-want-for-christmas