1. By Sean C. Solomon (Director, Lamont-Doherty Earth Observatory) "MESSENGER at Mercury: The Surprising Innermost Planet"

    Abstract: Launched in 2004, MESSENGER flew by Mercury three times in 2008-2009 en route to becoming the first spacecraft to orbit the solar system’s innermost planet in March 2011. Orbital observations over the subsequent 18 months have provided the first global view of this nearby but heretofore little studied world. MESSENGER’s chemical remote sensing measurements of Mercury’s surface indicate that the planet’s bulk silicate fraction, low in Fe and high in Mg, differs from those of the other inner planets. Moreover, surface materials are richer in the moderately volatile constituents S and K than predicted by most current models for inner planet formation. Global image mosaics and targeted high-resolution images reveal that Mercury experienced globally extensive volcanism, with large expanses of plains emplaced as flood lavas and widespread examples of pyroclastic deposits likely emplaced during explosive eruptions of volatile-bearing magmas. Bright deposits within impact craters host fresh-appearing, rimless depressions or hollows, often with high-reflectance interiors and halos and likely formed through processes involving the geologically recent loss of volatiles. The large-scale deformational history of Mercury, although dominated by near-global contractional deformation as first seen by Mariner 10, is more complex than first appreciated, with numerous examples of extensional deformation that accompanied impact crater and basin modification. Mercury’s magnetic field is dominantly dipolar, but the field is axially symmetric and equatorially asymmetric, a geometry that poses challenges to dynamo models for field generation. The interaction between the solar wind and Mercury’s magnetosphere, among the most dynamic in the solar system, serves both to replenish the exosphere and space weather the planet’s surface. Plasma ions of planetary origin are seen throughout the sampled volume of Mercury’s magnetosphere, with maxima in heavy-ion fluxes in the planet’s magnetic-cusp regions. Bursts of energetic electrons, seen at most local times, point to an efficient acceleration mechanism operating within Mercury’s magnetosphere on a regular basis that produces electrons with energies up to hundreds of keV on timescales of seconds.

    Uploaded 39 Plays / / 0 Comments Watch in Couch Mode
  2. This lecture is part of the The Earth Science Colloquium video series. The Earth Science Colloquium Series is sponsored by the Lamont-Doherty Earth Observatory and the Columbia University Department of Earth and Environmental Sciences (DEES). This series provides a lively forum for discussing a wide variety of topics within the earth sciences and related fields. Colloquia are attended by the full range of scientific and technical staff at LDEO.

    Craig Manning
    University of California, Los Angeles

    # vimeo.com/38433693 Uploaded 112 Plays / / 0 Comments Watch in Couch Mode
  3. This lecture is part of the The Earth Science Colloquium video series. The Earth Science Colloquium Series is sponsored by the Lamont-Doherty Earth Observatory and the Columbia University Department of Earth and Environmental Sciences (DEES). This series provides a lively forum for discussing a wide variety of topics within the earth sciences and related fields. Colloquia are attended by the full range of scientific and technical staff at LDEO.

    Katherine Freeman
    Pennsylvania State University

    # vimeo.com/38433363 Uploaded 64 Plays / / 0 Comments Watch in Couch Mode
  4. This lecture is part of the The Earth Science Colloquium video series. The Earth Science Colloquium Series is sponsored by the Lamont-Doherty Earth Observatory and the Columbia University Department of Earth and Environmental Sciences (DEES). This series provides a lively forum for discussing a wide variety of topics within the earth sciences and related fields. Colloquia are attended by the full range of scientific and technical staff at LDEO.

    Chris Paola
    St. Anthony Falls Laboratory, University of Minnesota

    # vimeo.com/38432554 Uploaded 46 Plays / / 0 Comments Watch in Couch Mode
  5. This lecture is part of the The Earth Science Colloquium video series. The Earth Science Colloquium Series is sponsored by the Lamont-Doherty Earth Observatory and the Columbia University Department of Earth and Environmental Sciences (DEES). This series provides a lively forum for discussing a wide variety of topics within the earth sciences and related fields. Colloquia are attended by the full range of scientific and technical staff at LDEO.

    Kim Cobb
    Associate Professor
    Georgia Institute of Technology

    # vimeo.com/38432400 Uploaded 27 Plays / / 0 Comments Watch in Couch Mode

Earth Science Colloquium Series

Lamont Doherty Plus

The Earth Science Colloquium Series is sponsored by the Lamont-Doherty Earth Observatory and the Columbia University Department of Earth and Environmental Sciences (DEES). This series provides a lively forum for discussing a wide variety of topics within


+ More

The Earth Science Colloquium Series is sponsored by the Lamont-Doherty Earth Observatory and the Columbia University Department of Earth and Environmental Sciences (DEES). This series provides a lively forum for discussing a wide variety of topics within the earth sciences and related fields.

Browse This Channel

Shout Box

Channels are a simple, beautiful way to showcase and watch videos. Browse more Channels. Channels