H2O at the Phoenix landing site.

نویسندگان

  • P H Smith
  • L K Tamppari
  • R E Arvidson
  • D Bass
  • D Blaney
  • W V Boynton
  • A Carswell
  • D C Catling
  • B C Clark
  • T Duck
  • E Dejong
  • D Fisher
  • W Goetz
  • H P Gunnlaugsson
  • M H Hecht
  • V Hipkin
  • J Hoffman
  • S F Hviid
  • H U Keller
  • S P Kounaves
  • C F Lange
  • M T Lemmon
  • M B Madsen
  • W J Markiewicz
  • J Marshall
  • C P McKay
  • M T Mellon
  • D W Ming
  • R V Morris
  • W T Pike
  • N Renno
  • U Staufer
  • C Stoker
  • P Taylor
  • J A Whiteway
  • A P Zent
چکیده

The Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5 degrees and 148 degrees ). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H(2)O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO(3), aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water.

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Perchlorates—inorganic compounds carrying the perchlorate ion (ClO4)—were discovered at the north polar landing site of the Phoenix spacecraft and at the southern equatorial landing site of the Curiosity Rover within the Martian soil at levels of 0.4–0.6 wt%. This study explores in laboratory experiments the temperature-dependent decomposition mechanisms of hydrated perchlorates—namely magnesiu...

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عنوان ژورنال:
  • Science

دوره 325 5936  شماره 

صفحات  -

تاریخ انتشار 2009