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Posts by ivy

October 8th, 2016: International Observe the Moon Night

Posted on Sep 9, 2016 in Featured, News

October 8th, 2016: International Observe the Moon Night

Please join us on the evening of Saturday 08 October, 2016 from 7 to 9 PM to participate and celebrate the 2016 edition of International Observe the Moon Night! We will have telescopes set up on the roof (9th floor) of UCLA’s Mathematical Sciences Building. It’s FREE, open to the public, and you’ll be able to observe the Moon (weather permitting). Please visit http://planets.ucla.edu/outreach/iotmn2016/ for more information and...

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October 28th, 2016: Bi-stability of Earth and what life may have to do with it

Posted on Sep 5, 2016 in Seminars

We consider a model of the evolution of the Earth including the water cycle and continental growth along with mantle convection and thermal evolution. The water cycle and continental growth and erosion are strongly non-linear feedback cycles that are coupled through the subduction of water carrying sediments and oceanic crust. Mantle viscosity is taken temperature and water concentration dependent. We plot our results in a series of phase planes spanned by mantle water concentration and continental coverage. The system starts with one fixed point in the phase plane and evolves to three fixed...

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December 2nd, 2016: Comet formation theories in the light of the Rosetta mission

Posted on Sep 5, 2016 in Seminars

Measurements from the Rosetta spacecraft at comet 67P show a low density, bilobate body containing volatile gases in addition to water. I will discuss implications of the Rosetta data for comet formation models.

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November 4th, 2016: Early Formation of the Moon 4.52 billion years ago

Posted on Sep 5, 2016 in Seminars

New isotopic measurements of lunar zircons require formation of the Moon within the first ~60 million years of solar system history. This age places the Moon-forming giant impact 100 million years earlier than many recent estimates.

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October 21st, 2016: Debris Disks and Distant Perturbers: The Transient State of the HD 106906 Disk

Posted on Sep 5, 2016 in Seminars

The HD 106906 system harbors an asymmetric disk and a very distant (>650 au) planetary-mass companion. We use collisional and dynamical simulations to investigate the interactions between the disk and the companion, and to use the disk’s observed morphology to place constraint’s on the companion’s orbit.

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October 14th, 2016: Solar System formation and evolution: hints on the origin of the diversity of planetary systems

Posted on Sep 5, 2016 in Seminars

I will present an outline of the major steps in the formation of the Solar System and its evolution towards the current structure. First, the generation of a global dichotomy, with multiple small (~Mars-mass) planetary embryos in the inner part and multi-­Earth-­mass giant planet cores in the outer part. Second, the onset of a dynamical barrier against the drift of icy particles into the inner system, due to the formation of proto-­Jupiter, which allowed the inner solar system to remain ice-­depleted despite the disk cooled during its evolution. Third, the inward migration of Jupiter,...

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October 7th, 2016: Large wind ripples on Mars: A record of atmospheric evolution

Posted on Sep 5, 2016 in Seminars

Large wind ripples on Mars are unlike any wind-blown sedimentary structures found in Earth’s sandy deserts. We propose that they form from the effect of wind drag on sand particles, such that preserved ripple stratification may shed light onto the early evolution of the martian atmosphere.

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September 30th, 2016: Origins of Gas Giant Compositions: The Role of Disk Location and Dynamics

Posted on Sep 5, 2016 in Seminars

The composition of planets is determined by and tightly linked to the composition of the protoplanetary disk in which they form. In the first part of my talk, I will discuss giant planet formation through core accretion. In the second part, I will explore how the composition and evolution of protoplanetary disks may affect the formation and chemical composition of giant planets.

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The Asteroid-Meteorite Connection Workshop at UCLA

Posted on Apr 8, 2016 in News

The iPLEX-hosted Asteroid-Meteorite Connection Workshop occurred on 21 and 22 April 2016 and featured an international cast of scientists researching asteroids, meteorites and comets using several methods with the hope of achieving a more complete understanding of the formation and evolution of planetesimals in the early Solar System and extrasolar systems.  Details regarding the final program of the workshop are available here:...

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UCLA Researcher Alan Rubin featured in New York Times article

Posted on Mar 11, 2016 in News

Dr. Alan Rubin, a researcher at UCLA and meteorite identification expert, was interviewed for a recent article by the New York Times. The article and Alan discuss the discovery of several meteorites in Florida and the history of the parent asteroid they likely came from. To read the full article, click here:...

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UCLA Professor emeritus narrows space between astronomy, environmentalism

Posted on Mar 2, 2016 in News

UCLA Astronomy Professor Emeritus Ben Zuckerman was recently featured in the Daily Bruin for his passion for environmentalism, conservation, and sustainability. Read more about Ben’s lifelong work here: http://dailybruin.com/2016/03/01/professor-emeritus-narrows-space-between-astronomy-environmentalism/

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Professor Ed Young named Fellow of two geochemical associations

Posted on Feb 10, 2016 in News

Professor Ed Young named Fellow of two geochemical associations

Congratulations to Department of Earth, Planetary, and Space Sciences Professor Ed Young who has been named a Fellow of the Geochemical Society and of the European Association of Geochemistry.  The award is “bestowed upon outstanding scientists who have, over some years, made a major contribution to the field of geochemistry”.  Ed will be honored at the Goldschmidt meeting in Yokohama this...

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March 11th, 2016: From “Honey Planets” to a Geodynamic Origin of Life

Posted on Feb 9, 2016 in Seminars

I present some novel insights based on first principles, parameterized 1D thermal history, and 3D spherical mantle convection evolution models, which raise doubt concerning many crucial assumptions commonly used in planetary geodynamics and allow for a new view on the thermal and tectonic evolution of rocky planets in our solar system and beyond. The new approach leads to massive rocky planets (Earth and bigger) remaining hotter for longer and plate tectonics being ideally initiated early on in the first 0.1-1Gyr driven by core cooling and boosted by a dry mantle and a late delivery of...

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Planets on Parade

Posted on Feb 9, 2016 in News

Planets on Parade

Late January and early February have provided spectacular views of the planets in the early morning sky. It is the first time that the bright planets that can be seen with the naked eye have been simultaneously visible since 2005. In their outward order from the sun, the five bright planets are Mercury, Venus, Mars, Jupiter and Saturn. They are visible because they are large and relatively close compared with other celestial objects like stars. Their surfaces and disks reflect sunlight and shine steadily, compared to the distant twinkling light that emanates from stars. Many of the planets...

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February 12th, 2016: When Photons Keep Secrets: New Observables for High Contrast Imaging Exoplanet Science

Posted on Feb 9, 2016 in Seminars

Detecting polarized light from self-luminous exoplanets has the potential to provide key information about rotation, surface gravity, cloud grain size, and cloud coverage. While field brown dwarfs with detected polarized emission are common, no exoplanet or substellar companion has yet been detected in polarized light. With the advent of high contrast imaging spectro-polarimeters such as GPI and SPHERE, such a detection may now be possible with careful treatment of instrumental polarization. I will discuss the role of polarimetry in brown dwarf and exoplanet science, test observations with...

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Bidding Farewell to UCLA Professor Mike Jura

Posted on Feb 2, 2016 in News

Bidding Farewell to UCLA Professor Mike Jura

It is with sadness that we report the passing of UCLA professor and distinguished astronomer, Michael Jura. A facet to the Department of Physics and Astronomy and an active member of iPLEX, Mike always encouraged the interdisciplinary blending of planetary science and astronomy. He made major contributions to the fields of theoretical and observational astronomy and was influential in the development of infrared astronomy and the Infrared Laboratory at UCLA, which now has instruments in many terrestrial and space telescopes. His presence will be missed in both the fields of astronomy and...

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February 5th, 2016: Spin-orbit coupling and the production of misaligned hot Jupiters via Lidov-Kozai oscillations

Posted on Feb 1, 2016 in Seminars

Many hot Jupiter systems exhibit significant misalignment between the orbital axis of the planet and the spin axis of its host star. While this misalignment could be primordial in nature, a large fraction of hot Jupiters are found in systems with distant stellar companions, and thus could have undergone Lidov-Kozai (LK) oscillations and acquired their misalignment dynamically. Here we present a study of the effect of spin-orbit coupling during LK oscillations, and the resulting spin-orbit misalignment angle distributions. We show that spin-orbit coupling induces complex, often chaotic,...

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February 19th, 2016: Continuing the Search for Planets in “Holey Debris Disks”

Posted on Jan 29, 2016 in Seminars

I will present the results from a survey of stars with “holey debris disks”, two-belt debris disks, in the southern hemisphere. I will briefly summarize the image processing techniques used to directly image these targets. We demonstrate that these disks with holes are good targets for directly detecting planets with the discovery of a planet around two of our targets, HD 95086 and HD 106906, at L’-band. The detected planets likely shepherd the outer cool debris belt. The relatively dust-free gap in these disks implies the presence of one or more closer-in planets. I will discuss our...

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UCLA scientists study the Moon-forming impact using oxygen isotopes

Posted on Jan 29, 2016 in News

UCLA scientists study the Moon-forming impact using oxygen isotopes

UCLA scientists Ed Young, Issaku Kohl, Paul Warren, and their collaborators are featured in Science today (January 29, 2016) with their paper “Oxygen isotopic evidence for vigorous mixing during the Moon-forming giant impact.” Using their new Panorama high-resolution mass spectrometer, which is housed at UCLA, the team has performed ultra-high precision oxygen isotope analyses of lunar samples. The compositions match those of Earth’s mantle rocks to within a few parts-per-million (in the Δ17O parameter), demonstrating that the Earth and Moon formed from the exact same reservoir of...

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January 22nd, 2016: The Strange and Fearsome Geology of Phobos

Posted on Jan 15, 2016 in Seminars

Phobos, the inner, asteroid-like satellite of Mars, is only 20 km diameter yet exhibits a perplexing geology. Orbiting well inside the corotation radius, and also inside the Roche limit, it will spiral into Mars in a few ten million years, and experiences increasing tidal deformation. Several features stand out: the crater Stickney, almost 10 km diameter, and complex networks of striations and pitted grooves. This talk will emphasize our recent work, that shows that the patterned striations are formed by the distortion of a weak elastic shell overlying an even weaker deformable interior...

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