Mar's ancient water was too acidic for supporting life.
Meanwhile, Opportunity's twin rover, Spirit, discovered
heightened concentrations of magnesium and iron
carbonates in a site called Comanche. This warm, less acidic
site could have supported life.
Not to be outdone by this rival rover,
Opportunity had a spectacular water discovery of its
own. Near the rim of the Endeavour Crater, veins of
gypsum were found inside some rocks. NASA
geologists theorized that these rocks were formed by
water flowing through cracks in the crater which, in
turn, deposited calcium. This was a startling
discovery that supported a belief that Mars might
have been — at one time — hospitable for life.
Finally, it was the Esperance target that
endeared Opportunity to all NASA scientist's hearts.
At the Endeavour Crater, Opportunity discovered clay
minerals formed in a neutral pH water. These
minerals would have been the basic beginning
building block needed for microbial life. Naturally,
the international press jumped on this story with
sensational headlines like: "Martians Really Did Exist!"
Yes, sort of, but certainly not the type of malevolent
Martians that invaded Earth in H. G. Wells' War of
the Worlds.
According to a team of scientists headed by
Opportunity Deputy Principal Investigator Ray
Arvidson (a professor at Washington University in St.
Louis, MO), the discoveries made by this rover are
helping to shape our knowledge of Mars. In fact,
Arvidson and his team claim that Opportunity's
"Esperance" target evidence is a landmark discovery.
"These rocks are older than any we examined earlier in
the mission, and they reveal more favorable conditions for
microbial life than any evidence previously examined by
investigations with Opportunity," said Arvidson. A complete
study of Opportunity's discovery was published as "Ancient
SERVO 03.2014 45
They Call Me Oppy
The vital stats for that rover that takes a licking and
keeps on ticking:
Launch from Earth: July 7, 2003
Launch Vehicle: Delta II H
Arrival on Mars: January 24, 2004 PST
Landing Site: Meridiani Planum
Odometer Reading: 24.07 miles
Number of Raw Images Returned: 187,000
Onboard sensors and tools: Panoramic camera,
miniature thermal emission spectrometer,
Moessbauer spectrometer, alpha particle X-ray
spectrometer, microscopic imager, rock abrasion
tool, navigation camera, hazard-avoidance cameras.
By comparison, the "other" NASA Mars rover, Spirit
landed in the Gusev Crater on January 3, 2004 and
ended operation in March 2010. A comic tribute to
Spirit painfully characterizes many NASA engineer’s
feelings about this "other" rover. You can read the
comic at http://xkcd.com/695/.
Before and after images of the same patch of
ground in front of NASA's Mars Exploration
rover Opportunity 13 days apart document
the arrival of a bright rock on to the scene.
The rover had completed a short drive just
before taking the second image, and one of
its wheels likely knocked the rock — dubbed
"Pinnacle Island" — to this position. The rock
is about the size of a doughnut. This Pinnacle
Island target may have been flipped upside
down when a wheel dislodged it, providing
an unusual circumstance for examining the
underside of a Martian rock. The site is on
Murray Ridge — a section of the rim of
Endeavour Crater where Opportunity is
working on north-facing slopes during its
sixth Martian winter.
