New gravity map suggests Mars has a porous crust

New gravity map suggests Mars has a porous crust
  1. New gravity map suggests Mars has a porous crust
    (NASA/Goddard Space Flight Center) NASA scientists have found evidence that Mars' crust is not as dense as previously thought, a clue that could help researchers better understand the Red Planet's interior structure and…

IMAGE: A new map of the thickness of Mars' crust shows less variation between thicker regions (red) and thinner regions (blue), compared to earlier mapping. This view is centered on Valles... view more 

Credit: NASA/Goddard/UMBC/MIT/E. Mazarico

NASA scientists have found evidence that Mars' crust is not as dense as previously thought, a clue that could help researchers better understand the Red Planet's interior structure and evolution.

A lower density likely means that at least part of Mars' crust is relatively porous. At this point, however, the team cannot rule out the possibility of a different mineral composition or perhaps a thinner crust.

"The crust is the end-result of everything that happened during a planet's history, so a lower density could have important implications about Mars' formation and evolution," said Sander Goossens of NASA's Goddard Space Flight Center in Greenbelt, Maryland. Goossens is the lead author of a Geophysical Research Letters paper describing the work.

The researchers mapped the density of the Martian crust, estimating the average density is 2,582 kilograms per meter cubed (about 161 pounds per cubic foot). That's comparable to the average density of the lunar crust. Typically, Mars' crust has been considered at least as dense as Earth's oceanic crust, which is about 2,900 kilograms per meter cubed (about 181 pounds per cubic foot).

The new value is derived from Mars' gravity field, a global model that can be extracted from satellite tracking data using sophisticated mathematical tools. The gravity field for Earth is extremely detailed, because the data sets have very high resolution. Recent studies of the Moon by NASA's Gravity Recovery and Interior Laboratory, or GRAIL, mission also yielded a precise gravity map.

The data sets for Mars don't have as much resolution, so it's more difficult to pin down the density of the crust from current gravity maps. As a result, previous estimates relied more heavily on studies of the composition of Mars' soil and rocks.

"As this story comes together, we're coming to the conclusion that it's not enough just to know the composition of the rocks," said Goddard planetary geologist Greg Neumann, a co-author on the paper. "We also need to know how the rocks have been reworked over time."

Goossens and colleagues started with the same data used for an existing gravity model but put a new twist on it by coming up with a different constraint and applying it to obtain the new solution. A constraint compensates for the fact that even the best data sets can't capture every last detail. Instead of taking the standard approach, known to those in the field as the Kaula constraint, the team created a constraint that considers the accurate measurements of Mars' elevation changes, or topography.

"With this approach, we were able to squeeze…

  1. New Study Says a Fast Radio Burst Happens Every Second in the Universe

    Universe Today - News
    09.22 / 01:36
    A new study by a team of researchers from the CfA argues that a Fast Radio Burst happens with every passing second in the observable Universe The post New Study Says a Fast Radio Burst Happens Every Second in the Universe appeared first on Universe…
  2. Indian lunar orbiter hit by heat rise

    CNNMoney - Space
    09.22 / 00:42
    Scientists have switched off several on-board instruments to halt rising temperatures inside India's first unmanned lunar…
  3. Inspiration for 'Contact' still listening

    CNNMoney - Space
    09.22 / 00:42
    From a remote valley in Northern California, Jill Tarter is listening to the…
  4. Shuttle lands at California air base

    CNNMoney - Space
    09.22 / 00:42
    NASA officials Sunday waved off the first opportunity for space shuttle Endeavour to return to Earth, citing poor weather…
  5. Mars Science Lab launch delayed two years

    CNNMoney - Space
    09.22 / 00:42
    NASA's launch of the Mars Science Laboratory -- hampered by technical difficulties and cost overruns -- has been delayed until the fall of 2011, NASA officials said at a news conference Thursday in…
  6. BepiColombo Mission To Fly Into 'Pizza-Oven-Like' Furnace Orbit Of Mercury - Astronomy
    09.22 / 00:12
    Scientists have unveiled the BepiColombo spacecraft that will travel to…
  7. Saturn’s Moon Titan Has Placid Lakes Just Right For Future Missions To Land Smoothly - Astronomy
    09.22 / 00:12
    Titan is a treasure-trove of calm, placid lakes with tiny…
  8. New release of the Meteosat Image Processing Facility -Space
    09.21 / 22:49
    A new release of the Meteosat Image Processing Facility (IMPF) is planned to be deployed on 6 December…
  9. OSI SAF netCDF Global Sea Ice Concentration product soon on EUMETCast -Space
    09.21 / 22:49
    The OSI SAF Level 3 Global Sea Ice Concentration product in netCDF format will be available on EUMETCast from 5…
  10. OSI SAF radiative fluxes products in netCDF4 soon on EUMETCast -Space
    09.21 / 22:49
    OSI SAF radiative fluxes products in netCDF4 format will be available on EUMETCast from 5…
  11. NASA-Produced Damage Maps May Aid Mexico Quake Response -Space
    09.21 / 22:49
    A new NASA-produced map of areas likely damaged by the Sept. 19 magnitude 7.1 Raboso earthquake near Mexico City may help responders and groups supporting response…
  12. Live coverage: Atlas 5 countdown and launch journal -Space
    09.21 / 22:49
    A United Launch Alliance Atlas 5 rocket will fly from Vandenberg Air Force Base in California on Thursday night to place a classified surveillance satellite into space for the U.S. National Reconnaissance…
  13. Six firm launch contracts booked with Arianespace -Space
    09.21 / 22:49
    Arianespace has received its first two confirmed launch contracts for Europe's new Ariane 6 rocket, and the company recently announced four more launch bookings to loft communications and weather satellites into orbit aboard Ariane 5 and Soyuz boosters from French…
  14. Hubble Spots Unusual Binary Asteroid in Main Belt - Space
    09.21 / 22:44
    Astronomers using the NASA/ESA Hubble Space Telescope have spotted an unusual object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. The active asteroid 300163 (also known as 2006 VW139) was discovered by Spacewatch in November 2006. Then the…
  15. Study: Easter Island May Have Had Population of 17,500 in Its Heyday - Space
    09.21 / 22:44
    A new study published in the journal Frontiers in Ecology and Evolution examines the relationship between agricultural potential and population on Easter Island before the arrival of European explorers. Easter Island, also known as Rapa Nui, is located in the easternmost corner of the Polynesian Triangle and is one of the most isolated locations on…
  16. ALMA Captures Smoky Bubble around Carbon Star U Antliae - Space
    09.21 / 22:44
    New observations from the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed a remarkably thin spherical shell around U Antliae, a star located in the southern constellation of Antlia, about 900 light-years away from Earth. U Antliae (also known as HD 91793 and HR 4153) is a so-called carbon star — an evolved, cool and luminous…
  17. Jellyfish Have Sleep-Like State, Biologists Discover - Space
    09.21 / 22:44
    Cassiopea jellyfish, a genus of true jellyfish found throughout the tropics in shallow ocean waters and mudflats, exhibit reversible behavioral quiescence during the night, according to a team of biologists at Caltech. Reported in the journal Current Biology, this finding is the first example of a sleep-like state in an organism with a diffuse nerve…
  18. Scientists Find New Evidence for Surface Water Ice at Mercury’s North Pole - Space
    09.21 / 22:44
    A new study led by Brown University planetary researchers adds three new large members to the list of water ice-filled craters near Mercury’s north pole and shows evidence that smaller-scale deposits scattered around the north pole; those deposits may be small, but they could add up to a lot more previously unaccounted-for ice. The idea […
  19. NASA Measures Hurricane Maria's Torrential Rainfall, Sees Eye Re-open -
    09.21 / 21:19
    The Global Precipitation Measurement mission or GPM core satellite, a joint mission between NASA and the Japan Aerospace Exploration Agency can measure rainfall from…
  20. Earth and Space Science Open preprint server to be powered by AGU and Atypon - Astronomy
    09.21 / 21:11
    (American Geophysical Union) The American Geophysical Union (AGU) and Atypon announced today a joint initiative to develop Earth and Space Science Open Archive (ESSOAr), a community server for the open dissemination of Earth and space science preprints and rich conference…