OT - Global Dust Storm that Ended Opportunity Helped Teach us howMars Lost its Water

On Saturday, May 4, 2019 at 8:44:54 AM UTC-7, a425couple wrote:
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The Global Dust Storm that Ended Opportunity Helped Teach us how Mars
Lost its Water

The enduring, and maybe endearing, mystery around Mars is what happened
to its water? We can say with near-certainty now, thanks to the squad of
Mars rovers and orbiters, that Mars was once much wetter. In fact that
planet may have had an ocean that covered a third of the surface. But
what happened to it all?

As it turns out, the global dust storms that envelop Mars, and in
particular the most recent one that felled the Opportunity rover, may
offer an explanation.

“The global dust storm may give us an explanation.�

Geronimo Villaneuva, Martian water expert, NASA’s Goddard Space flight
Center
Dust storms on Mars are common. They tend to be seasonal, taking place
during the spring and summer in the southern hemisphere. They last a
couple days and cover areas as large as the US. But then there are the
planet-encircling, or global, dust storms.

In mid-July 2018 the NASA/ESA Hubble Space Telescope observed Mars, only
13 days before the planet made its closest approach to Earth in 2018.
While previous images showed detailed surface features of the planet,
this new image is dominated by a gigantic sandstorm enshrouding the
entire planet. Global dust storms — lasting for weeks or months — tend
to happen during the spring and summer in the southern hemisphere, when
Mars is closest to the Sun and heating is at a maximum, leading to
greater generation of winds. Image Credit: NASA/ESA/Hubble STscI
The global dust storms are more unpredictable than their smaller,
seasonal counterparts. They appear every few years and can cover the
entire planet. And they can stick around for months on end. During the
last one, which lasted from June 2018 to September 2018, six orbiting
spacecraft and two surface rovers observed the storm, though
unfortunately Opportunity didn’t survive it.

Images of a drill site from NASA's Curiosity rover. The image on the
left was taken during normal Mars daytime, prior to the 2018 global dust
storm. The image on the right was captured when the global dust storm
was in full effect. Image Credit:
NASA/JPL-Caltech/MSSS

The question is, what causes these massive storms? How are they a part
of the Martian climate and atmosphere? Did they and do they contribute
to water loss? NASA scientists are trying to answer those questions.

First of all, a quick answer to an often-asked question: Why did
Opportunity perish in the global dust storm while Curiosity survived it?
Opportunity was solar powered, and the dust blotted out the Sun. There
may have been other causes, because no rover lasts forever, but the lack
of solar energy certainly played a part. But Curiosity is a
nuclear-powered machine, and it doesn’t care about the Sun.

A panorama image of the Opportunity rover, showing the solar panels. The
rover’s science operations were shut down because of the growing global
dust storm. By NASA/JPL-Caltech/Cornell –
http://marsrovers.jpl.nasa.gov/galle...20060104a.html
/ http://photojournal.jpl.nasa.gov/catalog/PIA03270, Public Domain,
https://commons.wikimedia.org/w/index.php?curid=514339
Back to the global dust storms.

We’ve witnessed several global dust storms on Mars. In 1971, the Mariner
9 spacecraft arrived at Mars and found it shrouded in dust. Since then,
we’ve seen storms in 1977, 1982, 1994, 2001, 2007 and 2018. There were
actually two separate global storms in 1977, adding to the mystery of
their cause.

Scott Guzewich is a NASA atmospheric scientists at the Goddard Space
Flight Center. He’s leading NASA’s investigation into Martian dust
storms. In a press release, Guzewich said, “We still don’t know what
drives the variability, but the 2018 storm gives another data point.�
And science is all about accumulating data points.

This image from the HiRise camera on the MRO shows a crater on Mars. On
the left is the crater before the global Martian dust storm, and on the
right is the same crater during the storm. Image: NASA/JPL/University of
Arizona
The dust storms may offer a clue to the case of Mars’ disappearing water.

Geronimo Villaneuva is a NASA scientist at the Goddard Space Flight
Center who has spent his career studying Martian water. Together with
colleagues at the European Space Agency and at the Roscosmos Russian
space agency, they think they may have it, at least partially, figured
out. “The global dust storm may give us an explanation,� Villaneuva said
in a press release.

It may come down to a combination of dust, the lofting of H2O into the
upper atmosphere, and the Sun’s radiation.

“When you bring water to higher parts of the atmosphere, it gets blown
away so much easier.�

Geronimo Villaneuva, NASA’s Goddard Space Flight Center
Global dust storms on Mars don’t only lift dust high into the
atmosphere. They also carry water. Typically, water is carried as high
as 20 km (12 miles) into the atmosphere. But Villaneuva and his
colleagues used the ExoMars Trace Gas Orbiter to detect water as high as
80km (50 miles) in the atmosphere during these global dust storms. At 80
km altitude, the Martian atmosphere is extremely thin, and the water is
exposed to solar radiation. That radiation can split apart the H2O
molecule, and the solar wind can blow the hydrogen and oxygen into space.

“When you bring water to higher parts of the atmosphere, it gets blown
away so much easier,� says Villanueva,

On Earth, lofted moisture condenses and falls to Earth as rain. But on
Mars, this may have never been the case. It’s possible that Mars slowly
lost its water over a long period of time through this mechanism.

Villaneuva and his colleagues presented their findings in a paper
published on April 10th, 2019 in the journal Nature.

Reality is dust would only make the bottom sand as are our ocean bottoms.No real evidence Mars had oceans.Mars atmosphere is only 1% as dense as Earth's,and has no moisture that is known. I see it as dry as our moon. Io is best for H20 Bert