Tag Archive for planetary
by Olivia Drake •
Three Wesleyan students, faculty and several alumni recently attended the 47th Lunar and Planetary Science Conference in The Woodlands, Texas.
This conference brings together international specialists in petrology, geochemistry, geophysics, geology and astronomy to present the latest results of research in planetary science. The five-day conference was organized by topical symposia and problem-oriented sessions.
Earth and environmental sciences graduate students Ben McKeeby and Shaun Mahmood, and earth and environmental science major Melissa Lowe ’17 presented their ongoing planetary science research at the conference. Lowe received a NASA CT Space Grant travel award to attend the conference.
The students were accompanied by their advisor, James Greenwood, assistant professor of earth and environmental sciences. Greenwood presented on “Volatile content of the lunar magma ocean: Constraints from KREEP basalts 15382 and 15386.” In addition, Martha Gilmore, chair and professor of earth and environmental sciences and the George I. Seney Professor of Geology, was an author on two Venus presentations at the conference.
Several alumni also made contributions at the planetary sciences meeting including Ian Garrick-Bethell ‘02; Peter Martin ‘14; Bob Nelson MA ‘69; James Dottin ‘13; Keenan Golder MA’13; Tanya Harrison MA ‘08; Nina Lanza MA ’06; and Ann Ollila MA ’06.
by Lauren Rubenstein •
Two faculty members and three students have been awarded grants in the latest call for proposals from NASA’s Connecticut Space Grant Consortium.
Jim Greenwood, assistant professor of earth and environmental sciences, and Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, professor of integrative sciences, were awarded $8,000 for a Faculty Collaboration Grant titled “Chondrule Formation Experiments.” This is to run high-temperature experiments on material that makes up meteorites in order to test a hypothesis that they put forward in a recent paper in Icarus this year.
Seth Redfield, associate professor of astronomy, associate professor of integrative sciences, was awarded $1,500 for a STEM Education Programming Grant
by Frederic Wills '19 •
Johan “Joop” Varekamp, the Howard T. Stearns Professor in Earth Science, led an invited talk at the American Geophysical Union (AGU) meeting in San Francisco, Dec. 2015.
The earth and space science community participated in discussions of emerging trends and the latest research. The session, which was co-authored by former Wesleyan E&ES graduate student Lauren Camfield, focused on the 2012 eruption of the Copahue volcano in Argentina.
Due to the success of the invited talk on Volcanic Hydrothermal Systems, Varekamp will be a co-editor for a special issue of a journal based on that session. As part of his role as chair-elect of the Committee on Geology and Public Policy of the Geological Society of America (GSA), he will be interviewing five candidates in Washington D.C. for the position of congressional fellow.
by Andrew Logan ’18 •
Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, and James Greenwood, assistant professor of earth and environmental sciences, co-authored an article published in the planetary science journal Icarus. Their article, “A New Mechanism for Chondrule Formation: Radiative Heating by Hot Planetesimals” grew out of research seminars from the recently introduced Planetary Science graduate concentration and minor at Wesleyan.
Their work focused on chondrules, or tiny spheres of molten rock that permeate primitive meteorites and date to very close to the beginning of the solar system.
For decades, the existence of chondrules has puzzled astrophysicists and cosmochemists as no obvious heat source exists at the time and location of their formation. Herbst and Greenwood set out to find this elusive heat source by combining their expertise in astronomy and earth science, respectively.
“It could be that the heat source is hot lava — oceans of magma– that may appear on nascent planets in their earliest days. The heat source is radioactive decay of a short-lived isotope of Aluminum, incubated in planetesimals with the size of small asteroids and brought to the surface as molten rock,” Herbst said.
Most of the material available for planet formation ends up on a planet very early on. A few “lucky bits,” represented by the primitive meteorites, avoided collision with a planet until just recently.
“It is, perhaps, not surprising that many, if not all of them, had a close encounter with a hot planetesimal that produced the chondrules and, likely, the chondritic meteorite in which they are embedded,” he said.
by Olivia Drake •
Kevin Flaherty, a postdoctoral researcher working with Meredith Hughes, assistant professor of astronomy, will speak on “Dusty Debris as a Window into New Planetary Systems” during the American Association for the Advancement of Science’s (AAAS) 2016 Annual Meeting in Washington, D.C., Feb. 13. Flaherty is one of three symposium speakers who will discuss the theme “Planet Formation Seen with Radio Eyes.”
Scientists are now probing how, where, and when planets form and are analyzing the links between planetary system architecture and the properties of the parent circumstellar disk. Though the relationship of planetary to stellar masses remains obscure, it is clear that most stars host planets. This symposium describes the state-of-the-art radio-wavelength observing campaigns astronomers are using to probe planet formation and samples new scientific results that radio telescopes are yielding.
After planetary systems form, small bodies analogous to Kuiper Belt Objects collide and produce dusty debris that can be seen around distant stars with radio interferometers. The structure of such debris disks is intimately connected with the dynamics of young planetary systems. In his presentation, Flaherty will describe how recent spectacular Atacama Large Millimeter/submillimeter Array observations of debris disks are revealing the properties of emerging planetary systems and the processes by which they form and evolve.
by Lauren Rubenstein •
Four Wesleyan undergraduates and a faculty member received awards in the latest call for proposals from NASA’s Connecticut Space Grant Consortium.
Astronomy major Rachel Aronow ’17 was awarded an Undergraduate Research Fellowship in the amount of $5,000 for her project, “Planet Formation and Stellar Characteristics in Tatooine-like Systems.” She is working with Bill Herbst, the John Monroe Van Vleck Professor of Astronomy, studying Tatooine-like systems (named after the fabled home system of Luke Skywalker), which are planet-forming disks that surround a close pair of stars that are in orbit around each other. Aronow conducted research with Herbst last summer, and these funds will support further work this academic year and possibly next summer.
Two students each received Student Travel Grants of $1,000. Melissa Lowe ’17, an earth and environmental sciences major, is working with James Greenwood, assistant professor of earth and environmental sciences, and will use the travel grant to present research at the Lunary and Planetary Conference in Houston, Tx. in March. Jesse Tarnas ’16, an astronomy and physics double major with a minor in planetary science, is working with Seth Redfield, associate professor of astronomy, associate professor of integrative sciences, on a project using data from the Kepler Space Telescope to measure the atmospheric and planetary properties of distant exoplanets. He is working on a senior thesis and will present preliminary results at the American Astronomical Society meeting in Florida this winter. He is also attending the American Geophysical Union meeting in San Francisco to present research he did as part of a summer research program at NASA Ames Space Academy.
Aylin Garcia Soto ’18 was awarded a $5,000 Undergraduate Scholarship, given to a student preparing for a career in STEM. Last summer, Garcia Soto worked at Williams College as part of the Keck Northeast Astronomy Consortium (KNAC) Research Experience for Undergraduates program, of which Wesleyan is a member.
Finally, Amrys Williams, visiting assistant professor of history, was awarded a Faculty STEM Education Programming Grant of $5,000 for the “Under Connecticut Skies” project. She is leading an effort that involves several faculty in the Astronomy Department, History Department, and Science in Society Program to create a museum exhibit in the library of the Van Vleck Observatory inspired by the celebration of the observatory’s centennial anniversary. Supported by the Connecticut Humanities Council, Williams led research with a team of student last summer into possible exhibit topics. This NASA CT Space Grant award will support the implementation of the exhibit.
by Olivia Drake •
The 26th Annual Undergraduate Research Symposium of the Keck Northeast Astronomy Consortium (KNAC) was held at Williams College on Oct. 17.
Five students presented results of their summer research: Julian Dann ’17, Aylin Garcia Soto ’18, and Girish Duvvuri ’17 delivered oral presentations while Rachel Aronow ’17 and Avi Stein ’17 presented a poster. Several other students came along to enjoy the weekend, which featured a dinner and social event on Friday night, the seminar on Saturday and breakout sessions on such topics as Inclusive Astronomy and how/why to program in Python.
More than 100 students and faculty from KNAC attended the event (pictured below):
by Olivia Drake •
On Sept. 30, NASA’s Discovery Program selected five planetary mission investigations for study during the next year as a first step in choosing one or two missions for launch as early as 2020. Wesleyan’s Martha Gilmore is on two of the investigation teams.
Gilmore, the George I. Seney Professor of Geology and chair of the Department of Earth and Environmental Sciences, is an expert on terrestrial planets. She studies the morphology and mineralogy of the surfaces of Venus and Mars using data from orbiting and landed spacecraft. She also is on the Executive Committee of NASA’s Venus Exploration Analysis Group which identifies scientific priorities and strategy for exploration of Venus.
Each of the five selected investigations will receive $3 million for one year to strengthen their proposed mission by doing in-depth concept design studies. At the end of the year, it is expected that one or two of the mission concepts will then be selected for flight.
“We’re absolutely ecstatic about this opportunity,” Gilmore said. “Venus is key to understanding how Earth-size planets operate in this solar system and in other solar systems. The driving question is why are Venus and Earth so different? Why is Earth the habitable twin planet? The measurements of Venus’ atmosphere and surface proposed by these missions are necessary to better understand the climate, volcanic activity and the habitability of Earth-size worlds.”
by Olivia Drake •
For her outstanding contributions to Milky Way research by observational methods, Meredith Hughes, assistant professor of astronomy, received the 2015 Bok Prize in Astronomy from Harvard University.
The prize, named in honor of Astronomer Bart Bok (1906–1983), is awarded to a recent holder of a PhD degree in the physical sciences from Harvard or Radcliffe who is under 35 years of age. Hughes received her PhD from Harvard in 2010, and a MA in astronomy from Harvard in 2007.
Hughes is an expert on planet formation, circumstellar disk structure and dynamics, gas and dust disk evolution and radio astronomy. She studies planet formation by observing the gas and dust in the disks around young stars, mostly using (sub)millimeter interferometers.
At Wesleyan, she teaches the courses Observational Astronomy, Radio Astronomy, Introductory Astronomy and Pedagogy Seminar.
She’s also the 2015 faculty advisor for the Wesleyan Women in Science organization (WesWIS) and serves on the American Astronomical Society Committee for the Status of Women in Astronomy and acts as the liaison between CSWA and the Working Group on LGBTIQ Equality.
by Olivia Drake •
Seth Redfield, associate professor of astronomy, and Marshall Johnson ’11 are the co-authors of an article titled “The Interstellar Medium in the Kepler Search Volume,” published in The Astrophysical Journal, Vol. 802, No. 2, July 2015. The article highlights ways scientists are studying the gas and dust in the galaxy near where the Kepler Space Telescope is discovering exoplanets.
“Stars, with planets, can interact with the gas surrounding them in interesting ways, like bubbles in a drink, where each of the bubbles is an individual star (perhaps with planets) and the drink is the ‘interstellar medium’, the gas in between the stars,” Redfield explained.
In addition, The New Scientist published an article on Aug. 6 titled, “Distant worlds could be sheltering in a bubble around their star,” which focuses on the authors’ Astrophysical Journal study. It reads:
Distant planets may be swaddled in a protective bubble of magnetism and charged particles, courtesy of their parent star. The first study to scrutinize these so-called astrospheres shows that some exoplanets are more well shielded than Earth, others not so lucky – and that their protection can be fickle.
Within our solar system, the sun’s wind of charged particles and radiation forms a bubble called the heliosphere, which repels cosmic rays that can affect Earth’s weather, eat away at the ozone layer and damage DNA. Likewise, astrospheres guard faraway worlds from the ravages of the cosmos, says Marshall C. Johnson, an astronomer at the University of Texas in Austin.
An astrosphere’s size is determined partly by the strength of the star’s winds, and partly by the surrounding interstellar medium of gas and dust. The star’s velocity through the galaxy also has an effect.
“It’s just like if you are driving and you stick your hand out the window. You will experience higher pressure on your hand when you are driving fast than when you are driving slowly,” Johnson says. “If there is a greater relative velocity between the star and the interstellar medium, there will be a greater pressure exerted on the astrosphere.”
Johnson is working on his PhD in astronomy at the University of Texas in Austin. Marshall and Redfield had gone together in 2010-11 to observe at the McDonald Observatory in west Texas, and this project grew out of this work.
Another co-author on the paper, Adam Jensen, was a postdoctoral researcher at Wesleyan between 2010-2013 and was funded by the National Science Foundation.
by Olivia Drake •
Seth Redfield, associate professor of astronomy, and Wilson Cauley, postdoctoral researcher in astronomy, led the effort on a paper titled “Optical hydrogen absorption consistent with a thin bow shock leading the hot Jupiter HD 189733b” accepted for publication in The Astrophysical Journal.
Bow shocks are ubiquitous astrophysical phenomena resulting from the supersonic passage of an object through a gas. In this paper, the authors present a robust detection of a time-resolved pre-transit, as well as in-transit, absorption signature around the hot Jupiter exoplanet HD 189733b using high spectral resolution observations of several hydrogen lines.
Better knowledge of exoplanet magnetic field strengths is crucial to understanding the role these fields play in planetary evolution and the potential development of life on planets in the habitable zone.
Cauley’s research is funded at Wesleyan through the National Science Foundation to study the extended atmospheres of exoplanets. For more information and to view a animation that summarizes the paper’s results, visit Cauley’s website.
In addition, Redfield and Cauley will present results from an observation made at the largest telescopes in the world, the Keck Telescope in Hawaii, during the International Astronomical Union General Assembly in August.