Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Miranda: An Icy Moon Deformed by Tidal Heating

19.09.2014

Miranda, a small, icy moon of Uranus, is one of the most visually striking and enigmatic bodies in the solar system.

Despite its relatively small size, Miranda appears to have experienced an episode of intense resurfacing that resulted in the formation of at least three remarkable and unique surface features -- polygonal-shaped regions called coronae.


Mosaic of southern hemisphere of Miranda, the innermost regular satellite of Uranus, with radius of 236 km. Projection is orthographic, centered on the south pole. Visible from left to right are Elsinore, Inverness, and Arden coronae. Image credit: NASA/Jet Propulsion Laboratory/Ted Stryk. See related article by Hammond and Barr.

These coronae are visible in Miranda’s southern hemisphere, and each one is at least 200 km across. Arden corona, the largest, has ridges and troughs with up to 2 km of relief. Elsinore corona has an outer belt that is approx. 80 km wide, relatively smooth, and elevated above the surrounding terrain by approx. 100 m. Inverness corona has a trapezoidal shape with a large, bright chevron at its center. The northern hemisphere of Miranda was never imaged by the Voyager 2 spacecraft, so it is unknown whether additional coronae exist.

Using numerical models, Noah Hammond and Amy Barr show that convection in Miranda's ice mantle likely formed the coronae. During convection, warm buoyant ice rose toward the surface, driving concentric surface extension beneath the locations of the coronae, causing the formation of extensional tectonic faults. This style of resurfacing is similar to plate tectonics on Earth, in that convection is a primary driving force for surface deformation.

Hammond and Barr write that the internal energy that powered convection probably came from tidal heating. Tidal heating would have occurred when Miranda was in an eccentric orbit -- moving closer to and further from Uranus. This caused the tidal forces from Uranus to vary, periodically stretching and squeezing Miranda and generating heat in its ice shell. Hammond and Barr find that convection powered by tidal heating explains the locations of the coronae, the deformation patterns within the coronae, and the estimated heat flow during corona formation.

FEATURED ARTICLE
Global resurfacing of Uranus’s moon Miranda by convection
Noah P. Hammond and Amy C. Barr, Dept. of Geological Sciences, Brown University, 324 Brook Street, Providence, Rhode Island 02912, USA. Published online ahead of print on 15 Sept. 2014; http://dx.doi.org/10.1130/G36124.1.

Other recently posted GEOLOGY articles (see below) cover such topics as
1. The 2004-2008 Mount St. Helens eruptions;
2. The largest landslides on Earth; and
3. The East African Rift Valley.

GEOLOGY articles published online ahead of print can be accessed online at http://geology.gsapubs.org/content/early/recent. All abstracts are open-access at http://geology.gsapubs.org/; representatives of the media may obtain complimentary articles by contacting Kea Giles.

Contact:
Kea Giles
Managing Editor,
GSA Communications
+1-303-357-1057
kgiles@geosociety.org

Kea Giles | Eurek Alert!
Further information:
http://www.geosociety.org/news/pr/2014/14-62.htm

More articles from Earth Sciences:

nachricht In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>