With the proliferation of discoveries of planets orbiting other stars, the race is on to find habitable worlds akin to the Earth. At present, however, extrasolar planets less massive than Saturn cannot be reliably detected. Astrophysicist John Chambers models the dynamics of these newly found giant planetary systems to understand their formation history and to determine the best way to predict the existence and frequency of smaller Earth-like worlds.

As part of this research, Chambers explores the basic physical, chemical, and dynamical aspects that led to the formation of our own Solar System--an event that is still poorly understood. His ultimate goal is to determine if similar processes could be at work in the newly discovered planetary systems, which could then help predict smaller, extrasolar bodies that might harbor life.

It is generally believed that the Earth and other terrestrial planets formed by the accretion of many rocky planetesimals. Water and other life-giving materials are thought to have originally accreted in planetesimals located beyond 1 astronomical unit (AU) from the Sun in the early solar nebula (1 AU = distance from the Earth to the Sun). These small bodies were subsequently driven toward the inner solar system by the gravitational perturbations from Jupiter and Saturn. Chambers’s models consider both observed and hypothetical planetary systems. He and colleagues recently calculated that the evolution of the terrestrial planets and the asteroid belt was heavily dependent on the orbital characteristics of the giant planets. He further demonstrated that the amount of volatiles present was affected by the timing of giant-planet formation.

Based on evidence of the rate of impact cratering on the Moon, Chambers recently proposed a bold hypothesis about our early Solar System: five planets instead of four originally accreted inside the asteroid belt. He believes that the missing fifth planet was in an unstable orbit between Mars and the asteroid belt and was ejected by 600 million years of gravitational perturbations induced by the other planets. He proposes that the missing planet’s exodus disrupted asteroid fields, creating an increase in lunar impacts.

Chambers received his B.A. in physics from Oxford University and his Ph. D. in astronomy from Manchester University.

Explore Carnegie Science

Alycia Weinberger
November 22, 2021

Washington, DC—Carnegie’s Alycia Weinberger and collaborators from the University of Texas at Austin and the Korean Astronomy and Space Science Institute received last month a $1.2 million grant from the Heising-Simons Foundation to develop an instrument for the Magellan telescopes at Carnegie’s Las Campanas Observatory in Chile that will enable breakthroughs in our understanding of the planet formation process.

Called MagNIFIES, for Magellans' Near-Infrared Five-band Immersion grating Efficient Spectrograph, the completed instrument will have the largest simultaneous spectral coverage of any high-resolution spectrograph in the world. It was the brainchild of

Rendering of the Giant Magellan Telescope courtesy of the GMTO.
November 5, 2021

Washington, DC—The National Academies of Science, Engineering, and Medicine Thursday ranked the U.S. Extremely Large Telescope program as a top strategic priority, recommending federal support for the final construction stages of the Giant Magellan Telescope, which is being built at Carnegie’s Las Campanas Observatory in Chile.

The Academies’ highly anticipated report, Pathways to Discovery in Astronomy and Astrophysics for the 2020s, was the result of its survey of the astronomy and astrophysics community regarding strategic goals and initiatives for the next 10 years.  The recommendation detailed that building an extremely large telescope “is

September 1, 2021

Pasadena, CA—Astronomer Ana Bonaca, for whom the Milky Way galaxy is laboratory to explore the evolution of the universe, has joined the Carnegie Observatories as a Staff Scientist.

Bonaca arrived this month from Harvard University where she held a prestigious Institute for Theory and Computation Fellowship. Prior to that she completed her Ph.D. in astronomy from Yale University and a master’s degree in physics from the University of Zagreb.

Bonaca studies how the uneven pull of our galaxy’s gravity affects objects called globular clusters—spheres made up of a million stars bound together and orbiting a galactic core. The Milky Way is enveloped by a

June 29, 2021

Washington, DC—A team of Carnegie astronomers was awarded $1.4 million from the Heising-Simons Foundation to develop an ambitious and versatile infrared spectrograph for the Magellan telescopes at Carnegie’s Las Campanas Observatory in Chile that will enable breakthroughs in understanding cosmology, galaxy evolution, and exoplanet atmospheres.

Spearheaded by instrument lead Nicholas Konidaris and project scientists Andrew Newman and Gwen Rudie of the Carnegie Observatories, the project, called the Magellan Infrared Multiobject Spectrograph, or MIRMOS, will expand researchers’ view of the sky in the infrared wavelengths of the spectrum and significantly advance

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The fund supports a postdoctoral fellowship in astronomy that rotates between the Carnegie Science departments of Terrestrial Magnetism in Washington, D.C., and the Observatories in Pasadena California. 

The Earthbound Planet Search Program has discovered hundreds of planets orbiting nearby stars using telescopes at Lick Observatory, Keck Observatory, the Anglo-Australian Observatory, Carnegie's Las Campanas Observatory, and the ESO Paranal Observatory.  Our multi-national team has been collecting data for 30 years, using the Precision Doppler technique.  Highlights of this program include the detection of five of the first six exoplanets, the first eccentric planet, the first multiple planet system, the first sub-Saturn mass planet, the first sub-Neptune mass planet, the first terrestrial mass planet, and the first transit planet.Over the course of 30 years we have

The Giant Magellan Telescope will be one member of the next class of super giant earth-based telescopes that promises to revolutionize our view and understanding of the universe. It will be constructed in the Las Campanas Observatory in Chile. Commissioning of the telescope is scheduled to begin in 2021.

The GMT has a unique design that offers several advantages. It is a segmented mirror telescope that employs seven of today’s largest stiff monolith mirrors as segments. Six off-axis 8.4 meter or 27-foot segments surround a central on-axis segment, forming a single optical surface 24.5 meters, or 80 feet, in diameter with a total collecting area of 368 square meters. The GMT

Along with Alycia Weinberger and Ian Thompson, Alan Boss has been running the Carnegie Astrometric Planet Search (CAPS) program, which searches for extrasolar planets by the astrometric method, where the planet's presence is detected indirectly through the wobble of the host star around the center of mass of the system. With over eight years of CAPSCam data, they are beginning to see likely true astrometric wobbles beginning to appear. The CAPSCam planet search effort is on the verge of yielding a harvest of astrometrically discovered planets, as well as accurate parallactic distances to many young stars and M dwarfs. For more see  http://instrumentation.obs.carnegiescience.edu/

Ana Bonaca is Staff Member at Carnegie Observatories. Her specialty is stellar dynamics and her research aims to uncover the structure and evolution of our galaxy, the Milky Way, especially the dark matter halo that surrounds it. In her research, she uses space- and ground-based telescopes to measure the motions of stars, and constructs numerical experiments to discover how dark matter affected them.

She arrived in September 2021 from Harvard University where she held a prestigious Institute for Theory and Computation Fellowship. 

Bonaca studies how the uneven pull of our galaxy’s gravity affects objects called globular clusters—spheres made up of a million

Peter Gao's research interests include planetary atmospheres; exoplanet characterization; planet formation and evolution; atmosphere-surface-interior interactions; astrobiology; habitability; biosignatures; numerical modeling.

His arrival in September 2021 continued Carnegie's longstanding tradition excellence in exoplanet discovery and research, which is crucial as the field prepares for an onslaught of new data about exoplanetary atmospheres when the next generation of telescopes come online.

Gao has been a part of several exploratory teams that investigated sulfuric acid clouds on Venus, methane on Mars, and the atmospheric hazes of Pluto. He also

Anne Pommier's research is dedicated to understanding how terrestrial planets work, especially the role of silicate and metallic melts in planetary interiors, from the scale of volcanic magma reservoirs to core-scale and planetary-scale processes.

She joined Carnegie in July 2021 from U.C. San Diego’s Scripps Institution of Oceanography, where she investigated the evolution and structure of planetary interiors, including our own Earth and its Moon, as well as Mars, Mercury, and the moon Ganymede.

Pommier’s experimental petrology and mineral physics work are an excellent addition to Carnegie’s longstanding leadership in lab-based mimicry of the

Johanna Teske became the first new staff member to join Carnegie’s newly named Earth and Planets Laboratory (EPL) in Washington, D.C., on September 1, 2020. She has been a NASA Hubble Fellow at the Carnegie Observatories in Pasadena, CA, since 2018. From 2014 to 2017 she was the Carnegie Origins Postdoctoral Fellow—a joint position between Carnegie’s Department of Terrestrial Magnetism (now part of EPL) and the Carnegie Observatories.

Teske is interested in the diversity in exoplanet compositions and the origins of that diversity. She uses observations to estimate exoplanet interior and atmospheric compositions, and the chemical environments of their formation