• ucsantabarbara twitter avatar
    UCSB’s 2017 Argyropoulos Lecture, “The Real Greek Life,” examines representations of Greek history & culture. https://t.co/Z1yObPKoK5
    1 hour 40 min ago
  • UCSBgauchos twitter avatar
    Moreno de Alboran Advances to First ITA Southwest Regionals Singles Championship in Program History https://t.co/gFomRfFLBB
    12 hours 5 min ago
  • UCSBgauchos twitter avatar
    Gauchos Fall 1-0 at Cal State Fullerton https://t.co/PGG96WtNIF
    14 hours 41 min ago
  • ucsantabarbara twitter avatar
    A UCSB biologist examines the benefits & drawbacks of virtual & augmented reality in teaching environmental science. https://t.co/uB40WL1q0O
    15 hours 20 min ago
  • UCSBgauchos twitter avatar
    .@UCSB_Volleyball makes it three wins for the week after sweeping CSUN Saturday night! RECAP >>>… https://t.co/Y0rCoOnBi6
    1 day 12 hours ago
  • UCSBgauchos twitter avatar
    .@UCSBMensSoccer takes on UC Davis in a battle for first tonight at Harder Stadium! Tune in here:… https://t.co/Zn3WPNjEok
    1 day 15 hours ago
  • UCSBgauchos twitter avatar
    UCSB Beats PAC-12's UCLA By 14 Points https://t.co/HGdLRkF1op
    1 day 18 hours ago
  • UCSBLibrary twitter avatar
    RT @Marikhasmanyan: Reppin @UCSBLibrary with @ForestSways and @Stahlmatt at #ArchivesBazaar if you're in the area stop by for a chat and gr…
    1 day 22 hours ago
  • UCSBLibrary twitter avatar
    RT @ForestSways: Come visit @UCSBLibrary archives table at #ArchivesBazaar https://t.co/tYLQmkTjDh
    1 day 23 hours ago
  • ucsantabarbara twitter avatar
    CA Assemblymember visited #UCSB’s food pantry after adopting a $7.5 million budget to combat food insecurity. https://t.co/tlWK9TZVIL
    2 days 54 min ago
  • UCSBgauchos twitter avatar
    No. 10 UCSB Drops Road Match to No. 8 Long Beach State, 10-6 https://t.co/vGlvB1TN23
    2 days 9 hours ago
  • UCSBgauchos twitter avatar
    Da Silveira and Dubavets Stay Afloat and Advance to Round of 16 https://t.co/ZSxtqldlOq
    2 days 10 hours ago
  • UCSBgauchos twitter avatar
    .@UCSB_Volleyball gets revenge, knocks off LBSU in four behind 26K-17D double-double from Lindsey Ruddins. RECAP >>… https://t.co/MVhhyi4I4J
    2 days 12 hours ago
  • UCSBgauchos twitter avatar
    Moreno de Alboran Shines in Day Two of ITA Southwest Regionals https://t.co/R1amVJQr0B
    2 days 12 hours ago
  • ArtsandLectures twitter avatar
    RT @sbseasons: Rhiannon Giddens Comes to Campbell Hall! 10/26 https://t.co/FyWnr2pSH7 @Sbseasons #seasonsmagazine #sb @artsandlectures @Rh
    2 days 18 hours ago

Data from MESSENGER Spacecraft Reveals New Insights on Planet Mercury

Wednesday, March 21, 2012 - 17:00
Santa Barbara, CA

2677-2.jpg

Mercury, as taken from the spacecraft MESSENGER.

Mercury, as taken from the spacecraft MESSENGER.

imagetn.aspx_.jpg

Stanton Peale

Photo Credit: 

George Foulsham, UCSB Office of Public Affairs and Communications

Thanks to the MESSENGER spacecraft, and a mission that took more than 10 years to complete, scientists now have a good picture of the solar system's innermost planet.

On March 17, MESSENGER (MErcury Surface, Space Environment, GEochemistry, and Ranging) completed its one-year primary mission, orbiting Mercury, capturing nearly 100,000 images, and recording data that reveals new information about the planet's core, topography, and the mysterious radar bright material in the permanently shadowed areas near the poles. The findings are presented in two papers published online in Science Express.

"Mercury is the last unexplored planet," said UC Santa Barbara physics professor emeritus Stanton Peale, who devised the procedure used for detecting whether or not Mercury had a liquid core. The way Mercury was formed, he said, may show some constraints on the formation of the solar system.

For one thing, Mercury's core is larger than expected –– almost 85 percent of the planetary radius. The Earth's core, in contrast, is just over half of the planet's radius. Additionally, Mercury appears to have a more complex core than Earth's –– a solid iron sulfide layer that is now part of the mantle, which encases a liquid core, which may float on a solid inner core.

The scientists, led by MIT researchers David E. Smith and Maria T. Zuber, also found that Mercury's solid outer core and liquid inner core contain more iron than Earth, relative to the whole planet, which influences the way Mercury's magnetic field was generated. However, Peale noted that the surface is comprised of lighter elements.

"We didn't expect so much sulfur," he said, adding that there was almost no iron found on the surface of the planet. With no iron, the volcanic surface rocks are too light to have come from a mantle with the large average density derived for the internal structure. This led to the concept of a two-layer mantle –– with a light upper silicate layer, which could provide the low-density surface material –– over a dense iron sulfide layer.

In the larger picture, the presence of inordinately large amounts of sulfur on the surface indicates that Mercury's formation was not as orderly as some scientists had previously assumed, according to Peale. "Mercury is composed of material that had condensed over a wide range from the Sun," he said.

Other findings include a precise topographic model of the planet's northern hemisphere, which reveals a smaller spread in elevations compared to those of Mars or the Moon.

Additionally, radar-bright features at the poles located in areas of permanent shadow have been found to be consistent with a water-ice hypothesis; however the notion has yet to be tested further with MESSENGER's neutron spectrometer.

MESSENGER is already on the next phase of its investigations: an extended year-long mission that includes more comprehensive and more targeted measurements.

MESSENGER Mission to Mercury
Stanton J. Peale