Scientists re-examining data from an old mission bring new insights to the tantalizing question of whether Jupiter's moon Europa has the ingredients to support life. The data provide independent evidence that the moon's subsurface liquid water reservoir may be venting plumes of water vapor above its icy shell.
Data collected by NASA's Galileo spacecraft in 1997 were put through new and advanced computer models to untangle a mystery — a brief, localized bend in themagnetic field — that had gone unexplained until now. Previous ultraviolet images from NASA's Hubble Space Telescope in 2012 suggested the presence of plumes, but this new analysis used data collected much closer to the source and is considered strong, corroborating support for plumes. The findings appear in Monday's issue of the journal Nature Astronomy.
NASA's Mars Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission is on a 300-million-mile (483-million-kilometer) trip to Mars to study for the first time what lies deep beneath the surface of the Red Planet. InSight launched at 4:05 a.m. PDT (7:05 a.m. EDT) Saturday from Vandenberg Air Force Base, California.
"The United States continues to lead the way to Mars with this next exciting mission to study the Red Planet's core and geological processes," said NASA Administrator Jim Bridenstine. "I want to congratulate all the teams from NASA and our international partners who made this accomplishment possible. As we continue to gain momentum in our work to send astronauts back to the Moon and on to Mars, missions like InSight are going to prove invaluable."
First reports indicate the United Launch Alliance (ULA) Atlas V rocket that carried InSight into space was seen as far south as Carlsbad, California, and as far east as Oracle, Arizona. One person recorded video of the launch from a private aircraft flying along the California coast.
Riding the Centaur second stage of the rocket, the spacecraft reached orbit 13 minutes and 16 seconds after launch. Sixty-one minutes later, the Centaur ignited a second time, sending InSight on a trajectory toward the Red Planet. InSight separated from the Centaur about 9 minutes later -- 93 minutes after launch -- and contacted the spacecraft via NASA's Deep Space Network at 5:41 a.m. PDT (8:41 a.m. EDT).
"The Kennedy Space Center and ULA teams gave us a great ride today and started InSight on our six-and-a-half-month journey to Mars," said Tom Hoffman, InSight project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "We've received positive indication the InSight spacecraft is in good health and we are all excited to be going to Mars once again to do groundbreaking science."
With its successful launch, NASA's InSight team now is focusing on the six-month voyage. During the cruise phase of the mission, engineers will check out the spacecraft's subsystems and science instruments, making sure its solar arrays and antenna are oriented properly, tracking its trajectory and performing maneuvers to keep it on course.
InSight is scheduled to land on the Red Planet around 3 p.m. EST (noon PST) Nov. 26, where it will conduct science operations until Nov. 24, 2020, which equates to one year and 40 days on Mars, or nearly two Earth years.
Read more at JPL News.
Roohi Dalal, a senior majoring in astrophysics and history, has received a Fulbright fellowship to travel to the Netherlands and study what the distribution of galaxies in space can tell us about fundamental properties of the universe.
The Fulbright Scholar Program, created by the U.S. Congress in 1946, is a cultural exchange program that offers grants to Americans who wish to perform research or pursue creative activities abroad. Over 150 countries are involved in the program, which sends approximately 1,200 Americans abroad each year.
At Leiden University in the Netherlands, Dalal will work with Alessandra Silvestri, a theoretical cosmologist, and postdoc Matteo Martinelli, to study how galaxies are distributed throughout the universe, and how this relates to fundamental questions in physics, such as how general relativity affects the universe on a grand scale. Dalal's research involves determining how to design galaxy surveys that can extract the most information about the nature of gravity at these large scales.
"I really like applying mathematical methods to these big, fundamental questions we're trying to answer," she says. "I think everyone wants to know where and how the universe started."
This will be Dalal's second trip to the Netherlands to conduct research. She spent two months last summer in an undergraduate research program, also at Leiden University.
"I really enjoyed it there," she says. "The research group environment was very collaborative, and I enjoyed living in Leiden, but I didn't feel like two months gave me a complete picture of life in the Netherlands. This is a great opportunity to be in a new environment, experience another culture, and learn how academia works in a different part of the world."
Dalal says her interest in astronomy began at a very early age.
"I grew up in New Hampshire, where the night sky was really beautiful because you could see a lot of stars," she says. "My parents got me a telescope and by first grade I decided I wanted to be an astronomer. Somehow, I stuck with it."
During her time at Caltech, Dalal has conducted research into dark matter and dark energy— as-yet-undetected forms of energy and matter believed to make up most of the universe—with the "Dark Sector" research group at JPL, which Caltech manages for NASA. She is currently working on a project with Olivier Dor
Shrinivas (Shri) Kulkarni, the George Ellery Hale Professor of Astronomy and Planetary Science at Caltech, and Erik M. Conway, historian for the Jet Propulsion Laboratory, which is managed by Caltech for NASA, have been named 2018 Guggenheim Fellows. Every year since 1925, the John Simon Guggenheim Memorial Foundation has awarded scholars, artists, and scientists with the fellowships, which come with an undisclosed amount of money. According to the foundation's website, the fellows are "appointed on the basis of prior achievement and exceptional promise." This year, 173 fellows were chosen out of 3,000 applicants.
Born in India and now a U.S. citizen, Kulkarni joined Caltech in 1985. He is a leading authority on exotic astrophysical phenomena such as gamma-ray bursts, brown dwarfs, and millisecond pulsars, and has been associated with many of the major advances in understanding the universe that have been made over the last decade. Kulkarni is the principal investigator behind the Zwicky Transient Facility at the Palomar Observatory—a state-of-the-art instrument that will rapidly scan the skies for objects that explode or otherwise change, such as supernovas and moving asteroids. The Zwicky Transient Facility took its first images in November of last year. Kulkarni is also the director of the Caltech Optical Observatories, which includes Palomar, Caltech's joint role in the W. M. Keck Observatory, and Caltech's joint role in the planned Thirty Meter Telescope.
Conway has been the historian for JPL since 2004. His work focuses on the intersection between science and technology with an emphasis on aerospace. He is currently completing a history of research in near-Earth objects. His most recent book, Exploration and Engineering: JPL and the Quest for Mars, was published in 2015 by Johns Hopkins University Press. In addition to his work for JPL, Conway co-authored Merchants of Doubtwith Naomi Oreskes. The book chronicles a small group of scientists who helped mislead the public about key findings on global warming, acid rain, and other well-established science topics.
More information about the Guggenheim Fellowships is online at gf.org.
The Juno mission, a probe sent by NASA to Jupiter and operated by JPL, has collected data indicating that the atmospheric winds of the gas giant planet run deep into its atmosphere and last longer than similar atmospheric processes found here on Earth. The findings, part of a four-article collection on Juno science results being published in the March 8 edition of the journal Nature, will improve understanding of Jupiter's interior structure, core mass and, eventually, its origin.
The Nature articles also include Juno science results showing that the massive cyclones that surround Jupiter's north and south poles are enduring atmospheric features, unlike anything encountered in our solar system.
"The depth of the winds on Jupiter has been debated for half a century," says David Stevenson, the Marvin L. Goldberger Professor of Planetary Science at Caltech, leader of the Interiors Working Group of Juno, and co-author of the Nature papers. "It matters because it helps us understand how the planet works. The two leading ideas were that the winds were very deep, an expression of how the planet convects from deep down; and that the winds were very shallow. The answer is neither." Stevenson believes that the winds are truncated about two or three kilometers below the surface because of their interaction with the planet's magnetic field, which provides a drag on the winds.
Read the full story from JPL News.
Every summer, Evan Kirby, assistant professor of astronomy at Caltech, recruits several high school students to join his research group. He assigns them independent astronomy projects, which he says allow the students to ask original questions that don't yet have answers. His students have gone on to excel in both non-science and science careers, including astronomy. One new goal of Kirby's is to get his graduate students involved in mentoring the high school students. He says that this kind of leadership experience is important for their future jobs.
For this initiative and other teaching and research proposals, Kirby has been named a 2018 Cottrell Scholar, an award that comes with a $100,000 grant and is designed to promote "outstanding teacher-scholars who are recognized by their scientific communities for the quality and innovation of their research programs and their academic leadership skills."
We sat down with Kirby to talk more about the award and his academic and teaching pursuits.
There are two parts to the Cottrell Award: research and teaching. Researchers submit their proposals and the winners receive unrestricted funds. For the research side of my proposal, I talked about looking at white dwarfs, the burnt-out cores of stars that exploded, and the elements created in those explosions. And, on the teaching side, I talked about using evidence-based learning to improve classroom teaching as well as wanting to get my graduate students involved in mentoring my summer high school students.
The proposal was called "Nucleosynthesis in Degenerate Objects," which is kind of a mouthful. Basically, it's related to what I study in general: the creation of the elements in the universe. For this particular proposal, I want to look at Type 1a supernovas, which are exploding white dwarfs, using a spectrograph on the W. M. Keck Observatory. Type 1a supernovas were the basis of the Nobel Prize-winning discovery of acceleration of the expansion of the universe.
Little is known about how white dwarfs explode. The traditional model is that they get to a certain mass, called the Chandrasekhar mass, then they explode, but there's more than one way to explode a white dwarf, including well below the Chandrasekhar mass. The mass at which the white dwarf explodes actually feeds directly into what elements it creates. So, by looking at the output of these blasts in galaxies that orbit our galaxy, called dwarf galaxies, I can look at the ratio of elements in those galaxies and learn something about how the white dwarfs exploded.
My ideas for the classroom reflect very much the talk that Carl Wieman, a physics professor from Stanford and Nobel Laureate, gave here a couple of weeks ago. In the last decade, he's been trying to introduce evidence-based teaching techniques into the classroom. These methods promote active learning, which is where the students are more involved in the classroom, rather than just passive. For example, you would want to break up lectures to make sure that the students' brains are working on solving problems. The idea is to get students thinking and talking to each other.
I would like to set up an online repository of classroom activities for the courses that I teach—which other professors can borrow from.
I first got involved in working with high school students while I was a graduate student at UC Santa Cruz. My advisor there, Puragra (Raja) Guha Thakurta, runs a large network of high school mentorship programs. I took a piece of that program with me when I started as a postdoc here at Caltech, and I still have some students from that area. Now, as a professor at Caltech, I recruit students from Pasadena High School with the help of the CTLO [Caltech's Center for Teaching, Learning, & Outreach] and their Summer Research Connection program. One of the things I look for in high school students is a fluency in computers. You cannot do research in astrophysics without some computer programming. For that reason, I specifically recruit students from Pasadena High School's App Academy, which has a heavy computer programming component.
I think we have a duty. We're not just here so we can learn things about the universe. We have a duty to share that knowledge with future generations, so that they can do even better than we did. If you don't teach the next generation of scientists the fundamentals, well, you're not going to have a next generation of scientists.
The search for extrasolar planets has uncovered a dizzying array of planetary systems. As part of that quest, researchers have found new planet types—lava worlds and super-Earths—as well as planets orbiting more than one star.
In his March 14 Watson Lecture, Andrew W. Howard, a professor of astronomy in the Division of Physics, Mathematics and Astronomy, will tour this diverse landscape with attention to planets similar to Earth in their size, mass, and temperature. He will consider recent discoveries that are providing tantalizing clues as to how our solar system formed and pointing the way to detailed characterizations of the atmospheres and compositions of Earth-like worlds using the next generation of instruments and telescopes. Howard will also describe the Keck Planet Finder (KPF), an instrument being developed by his group that will measure the properties of Earth-like planets and their larger cousins in exquisite detail.
Howard's research covers the formation and evolution of planets orbiting stars other than the sun, focusing on the diversity of small planets. He and his team discover and characterize these extrasolar planets using telescopes in Hawaii and California, and in space. Howard, who started at Caltech in 2016, received his bachelor's degree from MIT in 1998 and his PhD from Harvard University in 2006.
The lecture, held at 8 p.m. on Wednesday, March 14, at Beckman Auditorium, is a free event; no tickets or reservations are required.
Named for the late Caltech professor Earnest C. Watson, who founded the series in 1922, the Watson Lectures present Caltech and JPL researchers describing their work to the public. Many past Watson Lectures are available online at Caltech's YouTube site.
Neutron stars consist of the densest form of matter known: a neutron star the size of Los Angeles can weigh twice as much as our sun. Astrophysicists don't fully understand how matter behaves under these crushing densities, let alone what happens when two neutron stars smash into each other or when a massive star explodes, creating a neutron star.
One tool scientists use to model these powerful phenomena is the "equation of state." Loosely, the equation of state describes how matter behaves under different densities and temperatures. The temperatures and densities that occur during these extreme events can vary greatly, and strange behaviors can emerge; for example, protons and neutrons can arrange themselves into complex shapes known as nuclear "pasta."
But, until now, there were only about 20 equations of state readily available for simulations of astrophysical phenomena. Caltech postdoctoral scholar in theoretical astrophysics Andre da Silva Schneider decided to tackle this problem using computer codes. Over the past three years, he has been developing open-source software that allows astrophysicists to generate their own equations of state. In a new paper in the journal Physical Review C, he and his colleagues describe the code and demonstrate how it works by simulating supernovas of stars 15 and 40 times the mass of the sun.
The research has immediate applications for researchers studying neutron stars, including those analyzing data from the National Science Foundation's Laser Interferometer Gravitational-wave Observatory, or LIGO, which made the first detection of ripples in space and time, known as gravitational waves, from a neutron star collision, in 2017. That event was also witnessed by a cadre of telescopes around the world, which captured light waves from the same event.
"The equations of state help astrophysicists study the outcome of neutron star mergers—they indicate whether a neutron star is 'soft' or 'stiff,' which in turn determines whether a more massive neutron star or a black hole forms out of the collision," says da Silva Schneider. "The more observations we have from LIGO and other light-based telescopes, the more we can refine the equation of state—and update our software so that astrophysicists can generate new and more realistic equations for future studies."
More detailed information can be found in the Physical Review C study, titled "Open-source nuclear equation of state framework based on the liquid-drop model with Skyrme interaction." Other authors include Luke F. Roberts of Michigan State University and Christian D. Ott. The study was funded by Conselho Nacional de Desenvolvimento Cient
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