[meteorite-list] Re: Where on Earth Is Mars? Try sherghotty

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:16 2004
Message-ID: <20021120181906.34006.qmail_at_web11601.mail.yahoo.com>

Hi all -

Looks like I can do my part to save the government
some money and thus reduce the deficit.

Where on Earth is Mars? Nowhere, except in the
martian meteorites recovered here.

I can with certainty assert that Mt Etna is not like
the Martian volcanoes. As far as martian "volcanoes"
goes, it looks like shergotty (sherghotty) is martian
"lava": essentially CO2/mineral clathrate frozen by
pressure release. One could think of a volcanic mud
flow, BUT the working fluid is entirely DIFFERENT.

In other words, unlike Etna, there is no magma
involved in these martian "volcanoes" - and this may
be seen in the Observor and Surveyor imagery, where
the impact structures formed by impacts into most of
these martian volcanoes' "lava' fields clearly show
that the fields are not composed of lava.

Mars and Earth are very different planets. While the
laws of physics and chemistry hold on both planets,
"geological" and "marseological" process are very
different.

Mars is not Earth-like, it's Mars like, dammit. Maybe
someday NASA stop wasting our money in pandering to
the escapist obsessvie complusives who need an
Earth-like Mars, but in the meantime...

ep

--- NASA Jet Propulsion Laboratory <info_at_jpl.nasa.gov>
wrote:
> http://www.jpl.nasa.gov/earth/features/mars.cfm
>
> Where on Earth Is Mars?
> Jet Propulsion Laboratory
> Contact: Rosemary Sullivant (818) 393-7490
> November 18, 2002
>
> Among the thousands of visitors to Mt. Etna this
> year, one group came not
> just to look at one of most famous volcanoes on
> Earth. Dozens of scientists
> trekked up Etna together this fall to observe what
> Etna has in common with
> Mars.
>
> Researchers interested in what makes the red planet
> tick can't study the
> planet in person-at least not yet. To help them
> interpret what they see in
> Mars images and other remote sensing data--and to
> test their instruments and
> procedures--they turn to Earth.
>
> Though the two planets are very different, Earth
> offers many similarities,
> or analogs, to Mars. Some of these, such as
> Antarctica, are definitely off
> the beaten track. Others, however, such as Mt. Etna,
> are places where
> ordinary travelers might find themselves-- although
> perhaps unaware that
> what they're seeing is anything like our neighboring
> planet.
>
> "A site can be like Mars in a variety of ways," says
> JPL geologist Dr. Tom
> Farr, one of the participants in the "Exploring
> Mars' Surface and its Earth
> Analogues" workshop at Mt. Etna. "Since Mars is
> really cold, the first
> places you think of are Antarctica and the Arctic.
> These places provide a
> way to see some of the processes that probably take
> place on Mars- glaciers
> and permafrost. But a place can also be like Mars by
> having similar
> geological features, such as volcanoes, or processes
> like erosion and
> weathering."
>
> Volcanoes in Common
>
> The prominent volcanoes on Mars are large, old and
> apparently no longer
> active. "Though small by Mars' standards, Etna, like
> the majority of
> volcanoes on Earth, is basaltic," says Mars Odyssey
> Project Scientist Dr.
> Jeffrey Plaut, who was also in the Etna workshop.
> "We believe that Mars'
> volcanoes have the same composition."
>
> Etna also has an example of a volcanic process that
> scientists think may
> occur on Venus, the Moon, and possibly Mars, but
> until recently hadn't been
> seen before on Earth. "We see some long narrow
> channels on those planets
> that don't look like they were eroded by water,"
> says Farr. "We inferred
> that they were produced by lava, but until their
> discovery on Etna, we had
> never actually seen that happen."
>
> Not all of Earth's volcanoes match those on Mars.
> "Mt. St. Helens is not a
> good analog," says Plaut, "it's silica-rich and is a
> result of plate
> tectonics that do not seem to occur on Mars". For
> good examples of large
> shield volcanoes, the most common type on Mars,
> Plaut picks Mauna Loa and
> Kilauea. "The big island of Hawaii, which is the
> largest volcano on Earth,
> has been a tremendous Mars analog."
>
> On Mars, super-sized volcanoes sculpted the
> landscape by releasing huge
> amounts of lava. It's possible to see what that sort
> of event did on Earth
> along the Columbia River in Washington. "Some of the
> largest lava flows on
> Earth took place there," says Plaut. The area was
> repeatedly flooded by
> lava, which formed the great basaltic cliffs called
> the Columbia River
> Basalts. And in Idaho's Snake River Plain, "rift
> lava seeped over a large
> flat surface creating a volcanic plain that serves
> as a good terrestrial
> analog for extensive sheet lavas on Mars as well as
> Venus and the Moon,"
> says Farr.
>
> Mars in the Desert
>
> Earth's deserts have many examples of geological
> processes at play on Mars.
> "Processes in arid environments tend to create dunes
> and landforms eroded
> and etched by winds like those we see on Mars," says
> Plaut. "We also like
> the desert because there's not much vegetation and
> the geology is exposed at
> the surface as it is on Mars."
>
> Drier and cooler than most deserts, the Atacama in
> Chile is often considered
> a Mars analog. In the warm deserts of Tunisia at the
> edge of the Sahara and
> California's Mojave, wind-blown sand creates
> Mars-like dunes and landforms.
> Deserts in North Africa, China, Asia, and North
> America are home to
> wind-sculpted ridges known as yardangs, also common
> in the Martian
> landscape.
>
> On both planets, some of today's deserts were
> probably yesterday's lakes.
> The same process that created Utah's Bonneville Salt
> Flats may have shaped
> the dry lakebeds that dot the Martian landscape.
> "Mars seems to have had
> catastrophic floods," says Plaut. "not unlike those
> that took place in the
> Bonneville area in the ice age. As the glaciers
> retreated, the rapid
> draining of a large lake carved up the landscape
> creating distinctive
> landforms. There was a lot of water and a lot of
> energy."
>
> One of the most famous planetary analogies and
> laboratories is Death Valley.
> "It's like Mars in its tectonic, erosional and
> sedimentation processes,"
> says Plaut. "It looks like Mars, too. There's a spot
> called Mars Hill that
> reminds people very much of the Viking 2 Lander
> site."
>
> Impact Zone
>
> Many a meteor made its last stop on Mars and on
> Earth. Mars' surface is
> pockmarked with impact craters. Here on Earth, most
> are buried or have
> eroded away. The Haughton Crater on Devon Island in
> the Canadian Arctic is a
> well-known site for Mars-related studies. More
> accessible is the meteor
> crater in Winslow, Ariz. "It's fairly recent," says
> Plaut, "and
> well-preserved, like many we see on Mars."
>
> Geology may not be all that Mars and Earth have in
> common. In the search for
> life in extreme environments, like those which may
> exist on Mars,
> researchers are looking in places like Yellowstone
> and Hot Springs, Ark.
> "Because the Mars environment is so cold and dry,
> getting liquid water to
> the surface today may require hot spring activity,"
> says Plaut. "But people
> are studying all kind of ground water environments,
> hot or not, and caves as
> possible Mars analogs."
>
> As Mars exploration continues, new common ground
> between that planet and
> this one is likely to emerge. "Even as we learn more
> about Mars from the new
> missions," says Farr, "we'll go out and try to find
> places on Earth that are
> similar, continuing our search for better Mars
> analogs."
>
>
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Received on Wed 20 Nov 2002 01:19:06 PM PST