Winds of Change: James Webb Space Telescope Reveals Elusive Details in Young Star Systems
Planet-forming disks, maelstroms of gas and dust swirling around your stars, are nurseries that give rise to planetary systems, including our solar system. U of A astronomers have discovered new details of gas flows that sculpt those disks and shape them over time.
By Daniel Stolte, University Communications - October 4, 2024
Every second, more than 3,000 stars are born in the visible universe. Many are surrounded by what astronomers call a protoplanetary disk – a swirling "pancake" of hot gas and dust from which planets form. The exact processes that give rise to stars and planetary systems, however, are still poorly understood.
A team of astronomers led by University of Arizona researchers has used NASA's James Webb Space Telescope to obtain some of the most detailed insights into the forces that shape protoplanetary disks. The observations offer glimpses into what our solar system may have looked like 4.6 billion years ago.
Specifically, the team was able to trace so-called disk winds in unprecedented detail. These winds are streams of gas blowing from the planet-forming disk out into space. Powered largely by magnetic fields, these winds can travel tens of miles in just one second. The researchers' findings, published in Nature Astronomy, help astronomers better understand how young planetary systems form and evolve.
According to the paper's lead author, Ilaria Pascucci, a professor at the U of A Lunar and Planetary Laboratory, one of the most important processes at work in a protoplanetary disk is the star eating matter from its surrounding disk, which is known as accretion.
"How a star accretes mass has a big influence on how the surrounding disk evolves over time, including the way planets form later on," Pascucci said. "The specific ways in which this happens have not been understood, but we think that winds driven by magnetic fields across most of the disk surface could play a very important role."
Young stars grow by pulling in gas from the disk that's swirling around them, but in order for that to happen, gas must first shed some of its inertia. Otherwise, the gas would consistently orbit the star and never fall onto it. Astrophysicists call this process "losing angular momentum," but how exactly that happens has proved elusive.
To better understand how angular momentum works in a protoplanetary disk, it helps to picture a figure skater on the ice: Tucking her arms alongside her body will make her spin faster, while stretching them out will slow down her rotation. Because her mass doesn't change, the angular momentum remains the same.
For accretion to occur, gas across the disk has to shed angular momentum, but astrophysicists have a hard time agreeing on how exactly this happens. In recent years, disk winds have emerged as important players funneling away some gas from the disk surface – and with it, angular momentum – which allows the leftover gas to move inward and ultimately fall onto the star.
Because there are other processes at work that shape protoplanetary disks, it is critical to be able to distinguish between the different phenomena, according to the paper's second author, Tracy Beck at NASA's Space Telescope Science Institute.
While material at the inner edge of the disk is pushed out by the star's magnetic field in what is known as X-wind, the outer parts of the disk are eroded by intense starlight, resulting in so-called thermal winds, which blow at much slower velocities.
"To distinguish between the magnetic field-driven wind, the thermal wind and X-wind, we really needed the high sensitivity and resolution of JWST (the James Webb Space Telescope)," Beck said.
Unlike the narrowly focused X-wind, the winds observed in the present study originate from a broader region that would include the inner, rocky planets of our solar system – roughly between Earth and Mars. These winds also extend farther above the disk than thermal winds, reaching distances hundreds of times the distance between Earth and the sun.
"Our observations strongly suggest that we have obtained the first images of the winds that can remove angular momentum and solve the longstanding problem of how stars and planetary systems form," Pascucci said.
For their study, the researchers selected four protoplanetary disk systems, all of which appear edge-on when viewed from Earth.
"Their orientation allowed the dust and gas in the disk to act as a mask, blocking some of the bright central star's light, which otherwise would have overwhelmed the winds," said Naman Bajaj, a graduate student at the Lunar and Planetary Laboratory who contributed to the study.
By tuning JWST's detectors to distinct molecules in certain states of transition, the team was able to trace various layers of the winds. The observations revealed an intricate, three-dimensional structure of a central jet, nested inside a cone-shaped envelope of winds originating at progressively larger disk distances, similar to the layered structure of an onion. An important new finding, according to the researchers, was the consistent detection of a pronounced central hole inside the cones, formed by molecular winds in each of the four disks.
Next, Pascucci's team hopes to expand these observations to more protoplanetary disks, to get a better sense of how common the observed disk wind structures are in the universe and how they evolve over time.
"We believe they could be common, but with four objects, it's a bit difficult to say," Pascucci said. "We want to get a larger sample with James Webb, and then also see if we can detect changes in these winds as stars assemble and planets form."
UA News - Winds of Change: James Webb Space Telescope Reveals Elusive Details in Young Star Systems
OSIRIS-REx, 1 Year Later: Asteroid Sample Continues to Provide Clues About Early Solar System and Origins of Life on Earth
It's been a year since NASA's OSIRIS-REx spacecraft successfully delivered the largest-ever asteroid sample to Earth on Sept. 24, 2023.OSIRIS-REx, 1 Year Later: Asteroid Sample Continues to Provide Clues About Early Solar System and Origins of Life on Earth
It's been a year since NASA's OSIRIS-REx spacecraft successfully delivered the largest-ever asteroid sample to Earth on Sept. 24, 2023.
Since then, intriguing clues about the early solar system and potential origins of life on Earth have emerged from study of the sample, under the leadership of OSIRIS-REx principal investigator Dante Lauretta, a Regents Professor of planetary sciences at the University of Arizona.
The successful delivery of 4.3 ounces (122 grams) of material from near-Earth asteroid Bennu marked a pivotal moment in space exploration. The mission collected more than twice the initial requirement of 2 ounces, or 60 grams, of the asteroid's surface material. Initial examinations of the material revealed crucial information about the asteroid's composition. Researchers identified significant quantities of carbon-based compounds and hydrated minerals in the sample, supporting hypotheses about the potential role of asteroids in bringing essential components for life to early Earth.
Scientists also discovered in the sample the presence of magnesium sodium phosphate, a specific phosphate mineral that did not get captured during remote sensing of the asteroid. This suggests that Bennu's origins may be more complex than initially thought. It also hints that the asteroid could have been born from a larger, water-rich celestial body.
"A year after OSIRIS-REx returned its sample to Earth, I am amazed by the discoveries we've made," Lauretta said. "Finding organic compounds and signs of a watery past on Bennu brings us closer to understanding the origins of our solar system and the chemistry that may have sparked life on Earth. It's a powerful reminder of how deeply we are connected to the universe."
While the majority of the asteroid material remains under careful curation at NASA's specialized facilities, portions have been allocated to key research institutions, including the U of A. Select museums across the U.S. now display fragments of the extraterrestrial material, as part of an initiative to encourage more public engagement with this scientific achievement. The U of A's Alfie Norville Gem & Mineral Museum is one of three places in the U.S. to showcase a piece of Bennu.
Museum sample Tucked inside a clear container protected by a metal casing, this pebble collected from asteroid Bennu by the OSIRIS-REx spacecraft is on display at the University of Arizona's Alfie Norville Gem & Mineral Museum. By Chris Richards/University Communications
"The journey of OSIRIS-REx has surpassed our greatest expectations, thanks in large part to the dedication and insight of the students who have been at the heart of this mission," Lauretta said. "As a university-led project, we've been able to involve students directly in groundbreaking discoveries. These findings not only expand our scientific knowledge but also showcase the unique role a university can play in advancing space exploration, fostering a hands-on learning environment that prepares the next generation to lead the future of planetary science."
The OSIRIS-REx mission scope has expanded beyond its initial objectives. The spacecraft, now redesignated as OSIRIS-APEX, has embarked on a new mission to study near-Earth asteroid Apophis. This extended mission is led by Dani Mendoza DellaGiustina, an assistant professor at the university's Lunar and Planetary Laboratory. The OSIRIS-APEX mission aims to observe Apophis during the asteroid's close approach to Earth in 2029, which could provide unprecedented data on the interactions between near-Earth objects and Earth's gravitational field.
The study of Apophis holds particular significance for planetary defense strategies. As an asteroid representative of potentially hazardous near-Earth objects, Apophis could provide critical data for developing future planetary protection measures.
Following the Bennu sample return last year, the U of A also established the interdisciplinary Arizona Astrobiology Center to connect experts from multiple fields to collaborate on investigations into life's origins on Earth and its potential existence on other worlds. The center will also explore the relevance of discoveries about life's origins to different cultures and traditions around the world. The center recently received a $1 million gift from Eugene Jhong, a retired Google software developer turned philanthropist, to support its work.
UA News - OSIRIS-REx, 1 Year Later: Asteroid Sample Continues to Provide Clues About Early Solar System and Origins of Life on Earth
Ali Bramson Receives Ronald Greeley Early Career Award
Dr. Ali Bramson, 2018 LPL Alum, receives 2024 Ronald Greeley Early Career Award in Planetary Sciences from the American Geophysical Union.
The Art of Planetary Science 2025
The Art of Planetary Science is an annual art exhibition run by the University of Arizona's Lunar and Planetary Laboratory. This year's theme - "50 Years of Discovery and Mystery on Mars".
The Art of Planetary Science is an annual art exhibition run by the University of Arizona's Lunar and Planetary Laboratory to celebrate the beauty and elegance of space science.
We encourage people to submit visual, audio, and/or written art in up to three categories:
This year's theme, "50 Years of Discovery and Mystery on Mars," invites artists to reflect on the exploration of Mars starting with the Viking 1 lander and/or how this knowledge has expanded our understanding of other worlds.
Bennu Holds the Solar System's 'Original Ingredients,' Might have Been Part of a Wet World
OSIRIS-REx sample scientists took a deep dive into the rocks and dust returned from asteroid Bennu. They found that the sample is rich in carbon, nitrogen and organic compounds - essential components for life as we know it.
By Mikayla Mace Kelley, University Communications - June 26, 2024
A deep dive into the sample of rocks and dust returned from near-Earth asteroid Bennu by NASA's University of Arizona-led OSIRIS-REx mission has revealed some long-awaited surprises.
Bennu contains the original ingredients that formed our solar system, the OSIRIS-REx Sample Analysis Team found. The asteroid's dust is rich in carbon and nitrogen, as well as organic compounds, all of which are essential components for life as we know it. The sample also contains magnesium sodium phosphate, which was as a surprise to the research team, because it wasn't seen in the remote sensing data collected by the spacecraft at Bennu. Its presence in the sample hints that the asteroid could have splintered off from a long-gone, tiny, primitive ocean world.
Launched on Sept. 8, 2016, the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer spacecraft, dubbed OSIRIS-REx, began its journey to near-Earth asteroid Bennu to collect a sample of rocks and dust from the surface. OSIRIS-REx was the first U.S. mission to collect a sample from an asteroid. The spacecraft delivered the sample, weighing 4.3 ounces, or 121.6 grams, to Earth on Sept. 24, 2023.
"Finally having the opportunity to delve into the OSIRIS-REx sample from Bennu after all these years is incredibly exciting," said Dante Lauretta, principal investigator for OSIRIS-REx and Regents Professor of planetary sciences in the University of Arizona Lunar and Planetary Laboratory. "This breakthrough not only answers longstanding questions about the early solar system but also opens new avenues of inquiry into the formation of Earth as a habitable planet. The insights outlined in our overview paper have sparked further curiosity, driving our eagerness to explore deeper."
Lauretta is co-lead author of a paper published in Meteoritics & Planetary Science that details the nature of the asteroid sample. The paper also serves as an introduction to the Bennu sample catalog, an online resource where information about the sample is made publicly available and where scientists can request sample material for their own research.
"The publication of the first paper led by Dr. Lauretta and Dr. Connolly describing the Bennu sample is an exciting milepost for the mission and for the Lunar and Planetary Laboratory," said Mark Marley, director of the UArizona Lunar and Planetary Laboratory and head of the Department of Planetary Sciences. "Our faculty, scientists and students will continue to study the sample for years and decades to come. For now, we can only imagine the stories of the origins of our planet and the life upon it still to be told by the Bennu grains already in our laboratories."
A 'watery past' for Bennu?
Analysis of the Bennu sample unveiled intriguing insights into the asteroid's composition. Dominated by clay minerals, particularly serpentine, the sample mirrors the type of rock found at mid-ocean ridges on Earth, where material from the mantle, the layer beneath Earth's crust, encounters water.
This interaction between ocean water and materials from the Earth's mantle results in clay formation and gives rise to a variety of minerals including carbonates, iron oxides and iron sulfides. But the most unexpected discovery in the Bennu sample is the presence of water-soluble phosphates, Lauretta said. These compounds are components of biochemistry for all known life on Earth today.
A similar phosphate was found in the asteroid Ryugu sample delivered by the Japan Aerospace Exploration Agency's Hayabusa2 mission in 2020. But the magnesium sodium phosphate detected in the Bennu sample stands out for the lack of inclusions, which are like little bubbles of other minerals trapped within the rock, and the size of its grains, unprecedented in any meteorite sample, Lauretta said.
The finding of magnesium sodium phosphates in the Bennu sample raises questions about the geochemical processes that brought these elements together, and provides valuable clues about Bennu's historic conditions.
"The presence and state of phosphates, along with other elements and compounds on Bennu, suggest a watery past for the asteroid," Lauretta said. "Bennu potentially could have once been part of a wetter world. Although, this hypothesis requires further investigation."
From a young solar system
Despite its possible history of interaction with water, Bennu remains a chemically primitive asteroid, with elemental proportions closely resembling those of the sun.
"The sample we returned is the largest reservoir of unaltered asteroid material on Earth right now," Lauretta said.
The asteroid's composition offers a glimpse into the early days of our solar system, over 4.5 billion years ago. The rocks have retained their original state, having neither melted nor resolidified since their creation, affirming their pristine nature and ancient origins.
Hints at life's building blocks
The team has also confirmed the asteroid is rich in carbon and nitrogen. These elements are crucial in understanding the environments from which Bennu's materials originated and the chemical processes that transformed simple elements into complex molecules, potentially laying the groundwork for life on Earth.
"These findings underscore the importance of collecting and studying material from asteroids like Bennu – especially low-density material that would typically burn up upon entering Earth's atmosphere," said Lauretta. "This material holds the key to unraveling the intricate processes of solar system formation and the prebiotic chemistry that could have contributed to life emerging on Earth."
What's next
Dozens more labs in the United States and around the world will receive portions of the Bennu sample from NASA's Johnson Space Center in Houston in the coming months, and many more scientific papers describing the Bennu sample are expected in the next few years from the OSIRIS-REx Sample Analysis Team.
"The Bennu samples are tantalizingly beautiful extraterrestrial rocks," said the paper's co-lead author, Harold Connolly, the mission sample scientist who leads the Sample Analysis Team, professor at Rowan University in Glassboro, New Jersey, and a visiting research scientist at UArizona. "Each week, analysis by the OSIRIS-REx Sample Analysis Team provides new and sometimes surprising findings that are helping place important constraints on the origin and evolution of Earthlike planets."
UA News - Bennu Holds the Solar System's 'Original Ingredients,' Might have Been Part of a Wet World
Space Sciences, Water Resources, Geosciences Excel in Latest US News Global Ranking
The University of Arizona earned its best scores in the space science category, placing No. 8 overall, No. 6 in the U.S. and No. 2 among public universities.
By Nick Prevenas, University Communications - June 26, 2024
From space sciences to water resources, the University of Arizona is again recognized as one of the world's top research institutions.
UArizona ranked No. 115 out of 2,250 higher education institutions across more than 100 countries in the 2024-2025 Best Global Universities ranking, released Tuesday by U.S. News & World Report. The university ranked No. 44 among universities in the U.S. and No. 23 among public U.S. universities.
The ranking placed UArizona among the top 10% of all ranked universities across the globe.
UArizona earned its best scores in the space science category, placing No. 8 overall, No. 6 in the U.S. and No. 2 among public universities. The university earned top marks in this category for its research reputation, along with the number of citations and publications by UArizona researchers.
UArizona also retained its stellar rankings in water resources (No. 2 in the U.S., No. 29 globally) and geosciences (No. 10 in the U.S., No. 25 globally).
UArizona also earned top-100 global placements for its programs in meteorology and atmospheric sciences (No. 47), environment/ecology (No. 59), arts and humanities (tied for No. 78) and plant/animal sciences (No. 78).
"I am continually in awe of the brilliant scientists and scholars who teach and conduct research at the University of Arizona," said University of Arizona President Robert C. Robbins. "Their groundbreaking discoveries across a wide variety of disciplines help foster an environment of bold thinking that is necessary to address and solve the world’s biggest challenges. I am very proud to see the University of Arizona recognized as one of the world's top research institutions."
U.S. News & World Report's Best Global Universities ranks colleges and universities in 51 subjects – up from 47 the last time this list was updated, in October 2022. The University of Arizona earned a spot on 38 of the subject ranking lists.
The university's overall research reputation was ranked No. 47 in the U.S. and No. 98 globally.
The 10th annual Best Global Universities rankings provide insight into how research institutions compare throughout the world. To produce the global rankings, which are based on data and metrics provided by the analytics company Clarivate, U.S. News & World Report uses a methodology that focuses on a university's global and regional reputation and academic research performance using indicators such as citations and publications.
U.S. News uses a separate methodology for the subject-specific rankings that is based on academic research performance in each subject. U.S. News uses various measures, including publications and citations as well as indicators for global and regional reputation in each specific subject area.
UA News - Space Sciences, Water Resources, Geosciences Excel in Latest US News Global Ranking
Studying Arctic Glaciers with Airborne Radar: UArizona Project Attracts $30M from NASA
The Snow4Flow mission will measure glaciers' ice and snow thickness and help scientists better predict how glacial melting contributes to sea level change.
By Daniel Stolte, University Communications - June 10, 2024
A University of Arizona-led project that uses advanced airborne radar mounted to low-flying aircraft to study arctic glaciers is one of six new missions that have received funding by NASA.
Dubbed Snow4Flow, the mission is led by Jack Holt, a professor in the 
UArizona Lunar and Planetary Laboratory and the Department of Geosciences. It is one of only two missions, selected from 42 proposals, to be funded at $30 million. Four other projects will each receive $15 million.
The funding, announced April 19, comes from NASA's Earth Venture program, which focuses on missions that use instruments mounted on aircraft to make measurements that cannot be made from space.
Snow4Flow's goal is to get a better handle on the snowfall feeding into glaciers and how fast those glaciers move. In combination with climate models, this will allow researchers to make more accurate predictions about how glaciers shrink and grow, and how much they contribute to sea level change, Holt said.
"Those glaciers are retreating fast, and they're making a large contribution to sea level rise, but we don't know exactly how much and how that's going to change in the future," he said. "Right now, we can't accurately measure how much snow feeds into the glacier systems, and without knowing their ice thickness, you don't know the volume of ice flowing out from the glacier. Those are things that you can't measure with satellites from space."
Snow4Flow is designed to address a critical need of climate scientists in their efforts to develop accurate projections of sea level rise from the melting of land glaciers. Across four major study regions representing many hundreds of glaciers in the Northern Hemisphere – Alaska/Yukon, southeastern Greenland, the Canadian Arctic Archipelago and Svalbard archipelago in Norway – the Snow4Flow team will use microwave and long-wavelength radar sounders mounted to low-flying aircraft to measure snow accumulation and glacial ice thickness. The resulting data will inform models of glacier dynamics and their contributions to sea level rise.
One of Alaska's most iconic glaciers, the Malaspina Glacier spills out from the St. Elias Mountains onto the coastal plain as a "pancake of ice". Around the world, glaciers are threatened by a warming climate, and scientists need as much data as possible to refine climate prediction models. This photo was taken during a previous NASA-funded mission tasked with measuring annual changes in the thickness of glaciers, sea ice and ice sheets. - Brandon Tober/University of Arizona
While Holt's team will focus on studying glaciers in the Northern Hemisphere, the group expects the data collected over the course of the five-year project will be applicable to glaciers in other parts of the world. The measurements can be used to calibrate observations from different satellite missions, allowing scientists to monitor glaciers from space and improve models that predict how glaciers across the globe will behave and respond to climate change.
Snow4Flow centers around two instruments: one with low-frequency radar that generates the very long wavelengths needed to penetrate thick ice sheets, and another that operates at shorter wavelengths and is optimized to probe blankets of snow.
"We will mount them to small aircraft – fixed-wing, helicopters or both – which will fly low over glaciers that pass through mountain valleys," Holt said. "During those flights, we will collect data that essentially produce cross sections of the snow and glacier ice thickness."
"At the same time, these missions improve our ability to use satellites by calibrating algorithms that attempt to use spaceborne data for such purposes," he said.
The Snow4Flow team will use microwave and long-wavelength radar sounders mounted to low-flying aircraft to measure snow accumulation and glacial ice thickness. - Russell Mitchell
Rather than having science and instrument teams defined at the time of the proposal, the projects selected for the NASA funding will be open to other scientists who are interested in applying to join the effort. Holt expects to have a final team assembled by fall 2025 and to begin flight operations in spring 2026. The mission will take place over three years, capturing winter snowfall before snowmelt begins in the summer months.
Holt attributes Snow4Flow's success in attracting federal funding to a strategic cluster hire at the university that included Ali Behrangi in the Department of Hydrology and Atmospheric Sciences and Chris Harig in the Department of Geosciences, through the university's Earth Dynamics Observatory. In cluster hires, multiple scholars are recruited into one or more departments based on shared research interests. Behrangi studies snowfall in high-latitude, high-altitude regions and Harig studies ice mass loss using gravity measurements from space satellites.
"The University of Arizona's continued success in attracting this level of research funding is a direct consequence of our efforts to focus our recruitment in key areas in which we offer unparalleled expertise and strength," said University of Arizona President Robert C. Robbins. "Snow4Flow is a perfect example of such an opportunity, in which our researchers will get to assemble a dream team capable of developing solutions to some of the most pressing challenges of our time."
The university's Earth Dynamics Observatory, or EDO, combines UArizona strengths in space exploration, instrumentation and Earth sciences to learn more about our planet. Collecting information about Earth from space provides new information about how Earth systems work, how they are changing and how humans might anticipate and respond to changes.
Behrangi, a professor of hydrology and atmospheric sciences, said the observatory played a crucial role in the success of the Snow4Flow proposal "by encouraging innovative thinking, allowing the team to break free from conventional ideas and envision a broader, more impactful mission instead of settling for smaller, less ambitious proposals."
"These large federal programs are increasingly interdisciplinary, where they need teams assembled from many disciplines to come together and answer the big science questions of the day," said Harig, an assistant professor of geophysics. "Jack (Holt) was able to use our expertise within EDO to refine the project idea over the last few years and be very well positioned when the solicitation finally came out."
UA News - Studying Arctic Glaciers with Airborne Radar: UArizona Project Attracts $30M from NASA
Webb Telescope Finds Plethora of Carbon Molecules Around Young Star
An international team of astronomers, including University of Arizona scientists, has used NASA's James Webb Space Telescope to study the disk of gas and dust around a young, very low-mass star.
By ESA/Webb, STScI/NASA and University Communications - June 6, 2024
An international team of astronomers, including scientists from the University of Arizona, has used NASA's James Webb Space Telescope to study the disk of gas and dust around a young, very low-mass star. The results reveal the largest number of carbon-containing molecules seen to date in such a disk. The findings have implications for the potential composition of any planets that might form around this star.
Rocky planets are more likely than gas giants to form around low-mass stars, making them the most common planets around the most common stars in our galaxy. Little is known about the chemistry of such worlds, which may be similar to or very different from Earth. By studying the disks from which such planets form, astronomers hope to better understand the planet formation process and the compositions of the resulting planets.
The scientists' findings, published today in the journal Science, build on a 2009 study led by Ilaria Pascucci, a UArizona professor of lunar and planetary sciences, who is also a co-author of the new study. In their previous work, Pascucci's team used the Spitzer Space Telescope to identify that the gas composition of disks around very-low mass stars differs from that around solar-type stars or stars that have higher mass. Spitzer detected acetylene and hydrogen cyanide, which are simpler molecules that have a smaller number of carbons.
"The James Webb spectrum is fantastic. With higher resolution and sensitivity than Spitzer, it enabled detection of many carbon-bearing molecules – even complex ones like benzene," Pascucci said.
The study's findings demonstrate that the gas composition is very hydrocarbon rich and expands scientists' knowledge of the chemical complexity of disks around very low-mass stars, Pascucci said. These exoplanets could build an early atmosphere that is hydrocarbon rich – very different from the early atmosphere that Earth built.
Planet-forming disks around very low-mass stars are difficult to study because they are smaller and fainter than disks around high-mass stars. A program called the MIRI Mid-INfrared Disk Survey, or MINDS, aims to use Webb's unique capabilities to build a bridge between the chemical inventory of disks and the properties of exoplanets.
"Webb has better sensitivity and spectral resolution than previous infrared space telescopes," said lead study author Aditya Arabhavi, a Ph.D. student at the University of Groningen in the Netherlands. "These observations are not possible from Earth, because the emissions from the disk are blocked by our atmosphere."
In the new study, researchers explored the region around a very low-mass star known as ISO-ChaI-147, a 1 to 2 million-year-old star that weighs just 0.11 times as much as the sun. The spectrum revealed by Webb's Mid-Infrared Instrument, or MIRI, shows the richest hydrocarbon chemistry seen to date in a protoplanetary disk – a total of 13 different carbon-bearing molecules. The team’s findings include the first detection of ethane outside of our solar system, as well as ethylene, propyne and the methyl radical CH3.
"These molecules have already been detected in our solar system, like in comets such as 67P/Churyumov–Gerasimenko and C/2014 Q2 (Lovejoy)," Arabhavi said. "Webb allowed us to understand that these hydrocarbon molecules are not just diverse but also abundant. It is amazing that we can now see the dance of these molecules in the planetary cradles. It is a very different planet-forming environment than we usually think of."
The team indicates that the results have significant implications for the chemistry of the inner disk and the planets that might form there. Since Webb revealed the gas in the disk is so rich in carbon, there is likely little carbon left in the solid materials from which planets would form. As a result, the planets that might form there may ultimately be carbon-poor like Earth.
"This is profoundly different from the composition we see in disks around solar-type stars, where oxygen-bearing molecules like water and carbon dioxide dominate," said team member Inga Kamp, professor at the University of Groningen. "This object establishes that these are a unique class of objects."
"It's incredible that we can detect and quantify the amount of molecules that we know well on Earth, such as benzene, in an object that is more than 600 light-years away," said team member Agnés Perrin, research director at the Centre National de la Recherche Scientifique in France.
Next, the science team intends to expand their study to a larger sample of such disks around very low-mass stars to develop their understanding of how common or exotic such carbon-rich terrestrial planet-forming regions are.
"The expansion of our study will also allow us to better understand how these molecules can form," said team member and principal investigator of the MINDS program Thomas Henning, director of the Planet and Star Formation department at the Max-Planck-Institute for Astronomy in Germany. "Several features in the Webb data are also still unidentified, so more spectroscopy is required to fully interpret our observations."
UA News - Webb Telescope Finds Plethora of Carbon Molecules Around Young Star
Near-Earth Asteroid Was Blasted From a Crater on the Moon, Study Finds
For the first time, scientists have traced an asteroid to its exact place of origin – a particular crater on the moon.
By Daniel Stolte, University Communications - April 25, 2024
For the first time, scientists have traced an asteroid to its exact place of origin – a particular crater on the moon. Unlike most near-Earth asteroids, which are thought to hail from the main asteroid belt between the orbits of Mars and Jupiter, asteroid 2016 HO3, also known as Kamo'oalewa, was likely blasted from the Giordano Bruno crater on the moon's far side and has been hurtling through space for several million years, according to a study published in the journal Nature Astronomy.
Selected as the target of China’s Tianwen-2 mission, Kamo'oalewa has been in space for several million years as one of a few of Earth’s co-orbital asteroids, meaning it travels around the sun on a similar orbit as Earth. Measuring between 150 and 190 feet in diameter, the asteroid is about half the size of the "London Eye" Ferris wheel.
According to lead study author Yifei Jiao, a visting scholar at the University of Arizona Lunar and Planetary Laboratory who is also a doctoral student at Tsinghua University in Beijing, the report is the first account of a potentially hazardous near-Earth asteroid that has been linked to a specific crater on the moon.
Previous research pointing to Kamo'oalewa likely originating from the moon included its reflectance spectrum, which is more compatible with lunar materials rather than the general population of near-Earth asteroids, and its low orbital velocity relative to Earth, suggesting it originated close to the Earth-moon system. However, scientists had not succeeded in pinpointing its likely point of origin until now.
To shed light on the mystery, the research team used impact and dynamical modeling. The team included colleagues from Tsinghua University, UArizona, Beihang University in Beijing, the University of British Columbia and the Observatoire de la Côte d’Azur in France.
According to the simulations, it would have required an impactor of at least 1 kilometer (0.6 mile) in diameter to launch a large fragment like Kamo'oalewa beyond the moon's gravitational pull. According to the group's model, the impact would have dug up Kamo'oalewa from deep beneath the moon's surface, leaving behind an impact crater larger than 10 to 20 kilometers (6-12 miles) in diameter. Additionally, the crater would have to be younger than the average lifetime for near-Earth objects, which spans about 10 million to 100 million years, a very short and recent period in the history of the solar system.
While the lunar surface is riddled with thousands of craters from impacts spanning the moon's 4.5 billion year-history, only Giordano Bruno with its 14-mile diameter and estimated 4 million years of age fits the bill in terms of size and age, making it the most probable source of Kamo'oalewa's origin. The team also showed that this scenario is feasible from an impact dynamics perspective.
The discovery comes on the heels of two previous studies led by the UArizona Lunar and Planetary Laboratory: In 2021, a team obtained the first evidence suggesting that Kamo'oalewa was different from typical near-Earth asteroids and likely a fragment of the moon. Another team then concluded that there were indeed orbital pathways, albeit rare, for lunar crater fragments to reach an unusual orbit like Kamo'oalewa's.
"This was a surprise, and many were skeptical that it could come from the moon," said co-author and Lunar and Planetary Laboratory professor Erik Asphaug. "For 50 years we have been studying rocks collected by astronauts on the surface of the moon, as well as hundreds of small lunar meteorites that were ejected randomly by asteroid impacts from all over the moon that ended up on Earth. Kamo'oalewa is kind of a missing link that connects the two."
According to co-author and UArizona planetary sciences professor Renu Malhotra, the findings open up a source of near-Earth asteroids that has not been seriously studied until now, and they have revealed previously unknown orbital pathways for the transport of rocks from and between planetary bodies.
"Testing the new model of Kamo'oalewa's origin from a specific, young lunar crater paves the way for obtaining ground-truth knowledge of the damage that asteroid impacts can cause to planetary bodies," Malhotra said. In other words, it provides scientists with a natural laboratory to test ideas around asteroid impacts and get a better idea of what the consequences of such an event might be, should humankind ever experience one.
For a strip mall-size rock to be blasted out of the moon at several miles per second and sent into orbit required very specific circumstances, Malhotra explained.
"You’d think the impact event would pulverize and distribute the ejecta far and wide," Asphaug said. "But there it is. So, we turned the problem around and asked ourselves, 'How can we make this happen?'"
According to Asphaug, the model provides more than just an explanation for the origin story of one particular asteroid. How massive rocks can be ejected from the surface of a planet and survive intact can be informative for fundamental questions, such as the origin of life in the universe. One such theory, known as panspermia, suggests that life – or its ingredients – could have been brought to planetary bodies from other sources across space, in the form of "organic hitchhikers" coming along for the ride, Asphaug explained.
"While Kamo'oalewa comes from a lifeless planet, it demonstrates how rocks ejected from Mars could carry life – at least in principle," he said.
The Giordano Bruno impact event likely would have produced tens of hundreds of 10-meter-size ejecta fragments into space, according to Jiao.
"While most of that debris would have impacted the Earth as lunar meteorites over the course of less than a million years," he said, "a few lucky objects can survive in heliocentric orbits as near-Earth asteroids, yet to be discovered or identified."
The upcoming Tianwen-2 mission aims to return samples from Kamo'oalewa, potentially confirming its lunar origin and enriching our understanding of lunar impact dynamics and space weathering effects. Additionally, NASA's NEO Surveyor mission is anticipated to identify more members of this lunar-derived near-Earth population.
"Fans of crime drama know the importance of arriving at the scene while all the evidence is fresh," Asphaug said, pointing out the importance of sample return missions such as the UArizona-led OSIRIS-REx mission. "They open up the unsolved cases surrounding the origins of meteorites in our collections, which are thought to have come from hundreds of other primitive asteroids."
Because Kamo'oalewa is not a surface rock but was ejected from much deeper than any mission had ever sampled, Asphaug has high hopes for the Kamo'oalewa sample Tianwen-2 is expected to bring to Earth: "It will be different in important ways from any of the specimens we have so far – one of those connecting pieces that help you solve the puzzle."
UA News - Near-Earth Asteroid Was Blasted From a Crater on the Moon, Study Finds
Two UArizona Astrobiology Researchers Named AAAS Fellows
Lunar and Planetary Laboratory Regents Professor Dante Lauretta and Professor Dániel Apai named AAAS Fellows.
By Niranjana Rajalakshmi, University Communications - April 18, 2024
Two University of Arizona faculty members have been elected 2023 Fellows of the American Association for the Advancement of Science, the world's largest general scientific society, which includes more than 250 affiliated societies and academies of science, serving 10 million individuals.
The newest class of AAAS Fellows, announced Thursday, includes 502 scientists, engineers and innovators, including two UArizona researchers who were recognized for their contributions to astrobiology: Dante Lauretta, Regents Professor of Planetary Sciences in the College of Science and director of the Arizona Astrobiology Center, and Daniel Apai, professor of astronomy in the College of Science .
"I could not be more proud to have two of our star faculty members in astronomy and planetary sciences receive this prestigious recognition," said University of Arizona President Robert C. Robbins. "The University of Arizona has long been a powerhouse in space exploration, and the work of talented faculty like Dante Lauretta and Daniel Apai further cement the university's unrivaled legacy in astronomy, planetary sciences and astrobiology."
The annual Fellows Forum will be held in Washington, D.C., on Sept. 21 in conjunction with the 150th anniversary celebration of the AAAS Fellows program.
"As we celebrate the150th anniversary of the AAAS Fellows, AAAS is proud to recognize the newly elected individuals," said Sudip Parikh, AAAS chief executive officer and executive publisher of the Science family of journals. "This year's class embodies scientific excellence, fosters trust in science throughout the communities they serve, and leads the next generation of scientists while advancing scientific achievements."
Dante Lauretta
Lauretta, Regents Professor at the UArizona Lunar and Planetary Laboratory, has been recognized as a AAAS Fellow for "distinguished contributions to the field of astrobiology, particularly for leadership and advancements through the OSIRIS-REx mission."
Dante Lauretta
"It's quite an honor and I'm super excited – AAAS is a very prestigious organization at the forefront of science and science policy in the United States," Lauretta said.
Lauretta was the principal investigator of OSIRIS-REx, NASA's first U.S. mission to collect a sample from an asteroid. After its launch on Sept. 8, 2016, the OSIRIS-REx spacecraft traveled to the asteroid Bennu, collected a sample from the surface and returned the sample to Earth on Sept. 24, 2023. The sample will help scientists understand more about planet formation and the origin of life on Earth.
"We are getting into the detailed organic chemistry of the samples and really starting to test some of the fundamental ideas surrounding the origin of life," Lauretta said.
Lauretta did his undergraduate work at UArizona, where we earned a bachelor's degree in physics and mathematics from the College of Science and a bachelor's degree in Oriental studies with an emphasis in Japanese from the College of Humanities. He earned his doctorate in Earth and planetary sciences from Washington University in 1997 and worked as a postdoctoral research associate and associate research scientist at Arizona State University prior to joining the University of Arizona as an assistant professor in 2001.
Lauretta is also the director of the university's Arizona Astrobiology Center, which launched in October. The center focuses on astrobiological research on the origins, evolution and distribution of life in the universe. More than 40 faculty members across 13 disciplines from four colleges conduct research at the center.
"A lot of our research involves undergraduate and graduate students," Lauretta said. " We have some of the greatest laboratory instruments in the world for analyzing materials and we are looking forward to new students coming on board to continue this great work."
Daniel Apai
Apai, a professor in the Department of Astronomy and Steward Observatory and the Lunar and Planetary Laboratory and interim associate dean for research in the College of Science, is being honored for his "distinguished contributions to the field of astrobiology and astrophysics, particularly for advancements in understanding of habitable exoplanets and planetary systems."
Daniel Apai
Apai's research is centered around planet formation, planetary atmospheres, exoplanet discovery and characterization. He is the principal investigator of Alien Earths, a NASA-funded astrobiology project that explores the potential of nearby planetary systems for supporting life.
Alien Earths is a multidisciplinary project with 40 members and is one of the largest astrobiology research projects that NASA is funding, Apai said.
"We are integrating knowledge from several disciplines like astronomy, atmospheric sciences, chemistry, material sciences and cosmochemistry," he said. "We made very exciting discoveries."
Apai earned a doctorate in astrophysics from the University of Heidelberg in 2004 and joined the UArizona faculty in 2011.
Apai also leads another project, the Nautilus Space Telescope, in collaboration with colleagues at the UArizona Wyant College of Optical Sciences. Nautilus is a novel space telescope concept that involves the launch of a large fleet of identical telescopes made up of ultra-lightweight optics. The project's goal is to characterize 1,000 potentially Earthlike exoplanets to search for signatures of life.
"We are very close to completing a milestone; we are working on bringing this completely new type of telescope up to Mount Lemmon (north of Tucson) to test it on the sky," Apai said.