[meteorite-list] IAU Approves New Names for Ten Major Fault Scarps on Mercury
Ron Baalke
baalke at zagami.jpl.nasa.gov
Fri Jun 7 13:54:15 EDT 2013
http://messenger.jhuapl.edu/news_room/details.php?id=240
MESSENGER Mission News
June 7, 2013
IAU Approves New Names for Ten Major Fault Scarps on Mercury
The International Astronomical Union (IAU) recently approved a proposal
from the MESSENGER Science Team to assign names to 10 rupes, the long
cliff-like escarpments that formed over major faults along which one
large block of crust on Mercury was thrust up and over another. The IAU
has been the arbiter of planetary and satellite nomenclature since its
inception in 1919. In keeping with the established naming theme for
rupes on Mercury, all of the newly designated features are named after
ships of discovery.
"We proposed the name Enterprise Rupes for the longest rupes on
Mercury, which is 820 kilometers (510 miles) long. The USS Enterprise
was launched in 1874 and conducted the first surveys of the Mississippi
and Amazon rivers," says Michelle Selvans of the Center for Earth and
Planetary Studies at the National Air and Space Museum. Selvans led the
effort to name this group of rupes.
"We also recommended some fun names, such as Calypso Rupes, for
Jacques Cousteau's ship," she says. And other names were proposed for
their personal connections, such as Palmer Rupes, named after an
icebreaker research vessel on which Selvans sailed to conduct marine
geophysics research offshore of Antarctica. The other names are
* Alvin Rupes, after DSV Alvin. Built in 1964 as one of the
world's first deep-ocean submersibles, Alvin has made more than
4,400 dives. It can reach nearly 63 percent of the global ocean floor.
* Belgica Rupes, after RV Belgica. Built in 1884, this steamship
was originally designed as a whaling ship. It was converted to a
research ship in 1896 and took part in the Belgian Antarctic
Expedition of 1897-1901, becoming the first ship to overwinter in
the Antarctic.
* Carnegie Rupes, after a yacht launched in 1909 as a research
vessel. The ship was built almost entirely from wood and other
non-magnetic materials to allow sensitive magnetic measurements to
be taken for the Carnegie Institution's Department of Terrestrial
Magnetism. During 20 years at sea the vessel traveled nearly
500,000 kilometers (300,000 miles) and carried out a series of
cruises until an onboard explosion in port destroyed the ship in 1929.
* Duyfken Rupes, after a small Dutch ship built in the late 16th
century. In 1606, the vessel sailed from the Indonesian island of
Banda in search of gold and trade opportunities on the island of
Nova Guinea. Under the command of Willem Janszoon, the ship and
her crew did not find gold, but they did discover the northern
coast of a huge continent: Australia.
* Eltanin Rupes, after the USNS Eltanin, launched in 1957 as a
noncommissioned Navy cargo ship. The vessel was built with a
double hull and officially classified as an Ice-Breaking Cargo
Ship. In 1962, the ship was refitted to perform research in the
southern oceans and reclassified an Oceanographic Research Vessel.
Magnetic field measurements made with the Eltanin were critical in
validating the hypothesis of sea-floor spreading.
* Nautilus Rupes, after the Exploration Vessel Nautilus. In
service since 1967, the ship has conducted underwater studies in
archeology in the Mediterranean and Caribbean seas. The vessel is
currently equipped with remotely operated vehicles and a
high-bandwidth satellite communication system for remote science
and education.
* Terror Rupes, after the HMS Terror. Built in the early 1800s as
a British Royal Navy bomb vessel, the ship was involved in the
bombardment of Fort McHenry, one of the last battles of the War of
1812. The bombardment provided the inspiration for Francis Scott
Key to write the American national anthem "Star Spangled Banner."
After being retrofitted for polar exploration, the ship
participated in Antarctic exploration.
Selvans says that Mercury's rupes are revealing a great deal about the
evolution of the planet. Each feature formed over a major fault system
that accommodated kilometers of horizontal shortening of Mercury's
crust. The accumulated contraction taken up by the faults that underlie
the rupes collectively records the cooling and contraction of Mercury's
interior over the past 4 billion years of planetary history.
In choosing those rupes to receive names, the team picked from among the
longest and most geologically interesting features that have been imaged
by MESSENGER. "These features are easy to identify in images taken at
dawn and dusk, when they throw shadows along their entire length,"
Selvans says. "A crisp shadow that is only about 1 kilometer wide but
hundreds of kilometers long really stands out in images."
Since 1976, the IAU has approved names for 27 rupes on Mercury. The
latest names are the first new designations for rupes in more than five
years.
"The MESSENGER team is grateful to the IAU for their approval of formal
names for rupes on Mercury," adds MESSENGER Principal Investigator Sean
Solomon of Columbia University's Lamont-Doherty Earth Observatory.
"MESSENGER observations have revealed that these deformational features
accommodated far more crustal contraction than indicated by earlier
estimates. The new names will permit the MESSENGER team to document this
finding in a clear and straightforward manner. Moreover, the names give
us the opportunity to recognize that the exploration of Earth's oceanic
regions continues in parallel with the exploration of Earth's sister
planets."
More information about the names of features on Mercury and the other
objects in the Solar System can be found at the U.S. Geological Survey's
Planetary Nomenclature Web site:
http://planetarynames.wr.usgs.gov/index.html.
------------------------------------------------------------------------
MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and
Ranging) is a NASA-sponsored scientific investigation of the planet
Mercury and the first space mission designed to orbit the planet
and entered orbit about Mercury on March 17, 2011 (March 18, 2011 UTC),
to begin a yearlong study of its target planet. MESSENGER's extended
mission began on March 18, 2012, and ended one year later. A possible
second extended mission is currently under evaluation by NASA. Dr. Sean
C. Solomon, the Director of Columbia University's Lamont-Doherty Earth
Observatory, leads the mission as Principal Investigator. The Johns
Hopkins University Applied Physics Laboratory built and operates the
MESSENGER spacecraft and manages this Discovery-class mission for NASA.
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