t-dub
Vapor Sloth
ok, here is a weekender for you guys. 2 links, the first is the popular sci article and the second link (highly recommended) is the meat and potatoes from The Planetary Society blog. Can you say dielectric constant?
Sky & Telescope: http://www.skyandtelescope.com/comm...ence-for-Ancient-Martian-Ocean-139085114.html
Planetary Society Blog: http://www.planetary.org/blog/article/00003365/
Personally I believe Mars once fostered microscopic life and that evidence will eventually be found in fossils there. But an entire ocean . . . hmmm. Makes me rethink the possible, geologic time is deep, and what they are talking about happened a long time ago.
From the paper "Dielectric map of the Martian northern hemisphere and the nature of plain filling materials" http://www.agu.org/pubs/crossref/2012/2011GL050286.shtml
"A number of observations suggest that an extended ocean once covered a significant part of the Martian northern hemisphere. By probing the physical properties of the subsurface to unprecedented depth, the MARSIS/Mars Express provides new geophysical evidences for the former existence of a Late Hesperian ocean. The Vastitas Borealis formation, located inside a putative shoreline of the ancient ocean, has a low dielectric constant compared with that of typical volcanic materials. We show that the measured value is only consistent with low-density sedimentary deposits, massive deposits of ground-ice, or a combination of the two. In contrast, radar observations indicate a distribution of shallow ground ice in equilibrium with the atmosphere in the south polar region. We conclude that the northern plains are filled with remnants of a late Hesperian ocean, fed by water and sediments from the outflow channels about 3 Gy ago. "
Sky & Telescope: http://www.skyandtelescope.com/comm...ence-for-Ancient-Martian-Ocean-139085114.html
Planetary Society Blog: http://www.planetary.org/blog/article/00003365/
Personally I believe Mars once fostered microscopic life and that evidence will eventually be found in fossils there. But an entire ocean . . . hmmm. Makes me rethink the possible, geologic time is deep, and what they are talking about happened a long time ago.
From the paper "Dielectric map of the Martian northern hemisphere and the nature of plain filling materials" http://www.agu.org/pubs/crossref/2012/2011GL050286.shtml
"A number of observations suggest that an extended ocean once covered a significant part of the Martian northern hemisphere. By probing the physical properties of the subsurface to unprecedented depth, the MARSIS/Mars Express provides new geophysical evidences for the former existence of a Late Hesperian ocean. The Vastitas Borealis formation, located inside a putative shoreline of the ancient ocean, has a low dielectric constant compared with that of typical volcanic materials. We show that the measured value is only consistent with low-density sedimentary deposits, massive deposits of ground-ice, or a combination of the two. In contrast, radar observations indicate a distribution of shallow ground ice in equilibrium with the atmosphere in the south polar region. We conclude that the northern plains are filled with remnants of a late Hesperian ocean, fed by water and sediments from the outflow channels about 3 Gy ago. "
