[meteorite-list] Mystery Rock 'Appears' in Front of Mars Rover Opportunity

[Ron Baalke]

http://news.discovery.com/space/mystery-rock-appears-in-front-of-mars-rover-140117.htm

Mystery Rock 'Appears' in Front of Mars Rover
by Ian O'Neill
Discovery News
January 17, 2014

[Images]
A comparison of two raw Pancam photographs from sols 3528 and 3540 of 
Opportunity's mission (a sol is a Martian day). Notice the "jelly doughnut"-sized 
rock in the center of the photograph to the right. Minor adjustments for 
brightness and contrast.
NASA/JPL-Caltech

After a decade of exploring the Martian surface, the scientists overseeing 
veteran rover Opportunity thought they'd seen it all. That was until a 
rock mysteriously "appeared" a few feet in front of the six  wheeled rover 
a few days ago.

News of the errant rock was announced by NASA Mars Exploration Rover lead 
scientist Steve Squyres of Cornell University at a special NASA Jet Propulsion 
Laboratory "10 years of roving Mars" event at the California Institute 
of Technology (Caltech), Pasadena, Calif., on Thursday night. The science 
star-studded public event was held in celebration of the decade since 
twin rovers Spirit and Opportunity landed on the red planet in January 
2004.

While chronicling the scientific discoveries made by both rovers over 
the years, Squyres discussed the recent finding of suspected gypsum near 
the rim of Endeavour Crater - a region of Meridiani Planum that Opportunity 
has been studying since 2011 - and the discovery of clays that likely 
formed in a pH-neutral wet environment in Mars past. While these discoveries 
have been nothing short of groundbreaking, Squyres shared the Mars rover's 
team's excitement for that one strange rock, exclaiming: "Mars keeps throwing 
new stuff at us!"

In a comparison of recent photographs captured by the rover's panoramic 
camera, or Pancam, on sol 3528 of the mission, only bare bedrock can be 
seen. But on sol 3540, a fist-sized rock had appeared (raw Pancam images 
can be found in the mission archive). MER scientists promptly nicknamed 
the object "Pinnacle Island."

"It's about the size of a jelly doughnut," Squyres told Discovery News. 
"It was a total surprise, we were like 'wait a second, that wasn't there 
before, it can't be right. Oh my god! It wasn't there before!' We were 
absolutely startled."

But the rover didn't roll over that area, so where did Pinnacle Island 
come from?

Only two options have so far been identified as the rock's source: 1) 
The rover either "flipped" the object as it maneuvered or, 2) it landed 
there, right in front of the rover, after a nearby meteorite impact event. 
The impact ejecta theory, however, is the least likely of the two.

"So my best guess for this rock...is that it's something that was nearby," 
said Squyres. "I must stress that I'm guessing now, but I think it happened 
when the rover did a turn in place a meter or two from where this rock 
now lies."

Opportunity's front right steering actuator has stopped working, so Squyres 
identified that as the possible culprit behind the whole mystery.

Each wheel on the rover has its own actuator. Should an actuator jam or 
otherwise fail, the robot's mobility can suffer. In the case of this wheel, 
it can no longer turn left or right. "So if you do a turn in place on 
bedrock," continued Squyres, "as you turn that wheel across the rock, 
it's gonna kinda 'chatter.'" This jittery motion across the bedrock may 
have propelled the rock out of place, "tiddlywinking" the object from 
its location and flipping it a few feet away from the rover.

Never missing a scientific opportunity, Opportunity scientists hope to 
study the bright rock. "It obligingly turned upside down, so we're seeing 
a side that hasn't seen the Martian atmosphere in billions of years and 
there it is for us to investigate. It's just a stroke of luck," he said.

"You think of Mars as being a very static place and I don't think there's 
a smoking hole nearby so it's not a bit of crater ejecta, I think it's 
something that we did...we flung it."

Although this is the leading theory behind the case of the random rock, 
Squyres pointed out that the investigation is still under way and it will 
be a few days before his team can definitively say where Pinnacle Island 
came from.

Opportunity has outlived its 3-month primary mission by ten years, notching 
up nearly 23 miles on the odometer so far. Sister rover Spirit succumbed 
to the Martian elements in 2009 when it became stuck in a sand trap in 
Gusev Crater. Spirit's mission was declared lost when it stopped transmitting 
in March 2010, likely drained of energy. Although Spirit had the rougher 
time on Mars and was the  first to die, it was also a huge success, aiding 
our understanding of of Mars' geological history and outliving its warranty 
by 5 years. But now it's just Opportunity and Mars' new arrival Curiosity 
that soldier on to reveal more than we ever dreamed about our neighboring 
red planet.

As the NASA Jet Propulsion Laboratory rover drivers, scientists and engineers 
recounted stories of their beloved robots on Thursday, it became very 
clear that they aren't just machines of discovery, they are family.

------------------------------------------

http://www.universetoday.com/108225/the-rock-that-appeared-out-of-nowhere-on-mars/ 

The Rock that Appeared Out of Nowhere on Mars
by Nancy Atkinson 
Universe Today
January 17, 2014

[Image]
Screenshot from Steve Squyres presentation celebrating 10 years of the 
Mars Exploration Rovers. A rock suddenly appeared where there was none 
12 sols earlier.

During last night's celebration at the Jet Propulsion Laboratory of ten 
years of the Mars Exploration Rovers, mission principal investigator Steve 
Squyres shared several stories about the exploration and discoveries made 
by the rovers Spirit and Opportunity since they landed on Mars in 2004. 
An intriguing recent mystery is a strange rock that suddenly appeared 
in photos from the Opportunity rover in a spot where photos taken just 
12 sols earlier there was no rock.

"One of the things I like to say is that Mars keeps throwing new things 
at us," Squyres deadpanned.

[Image]
A colorized version of the rock called Pinnacle Island. Credit: NASA/JPL, 
color by Stuart Atkinson.

Squyres described the rock as "white around the outside, in the middle 
there's low spot that is dark red. It looks like a jelly donut," he said. 
"And it appeared. It just plain appeared and we haven't driven over that 
spot."

They've named it "Pinnacle Island," and the team is contemplating a few 
ideas of why the rock mysteriously showed up.

"One theory is that we somehow flicked it with a wheel," Squyres said. 
"We had driven a meter or two away from here and somehow maybe one of 
the wheels managed spit it out of the ground. That's the more likely theory."

The other?

"The other theory is that there might be a smoking hole in the ground 
nearby and this may be crater ejecta. But that one is less likely," Squyres 
said.

Another idea suggested by others is that it may have tumbled down from 
a nearby rock outcrop.

[Image]
Image from Sol 3528 of the area showing no rock. Click to see original 
on the rover's raw image website. Credit: NASA/JPL.

[Image]
Image of same area on Sol 3540 where the "jelly donut" rock appears. Click 
to see original. Credit: NASA/JPL.

But as intriguing as the sudden appearance of the rock is what the team 
is finding out about it.

"We are as we speak situated with the rover, with its instruments, making 
measurements on this rock. We've taken pictures of both the donut part 
and the jelly part," Squyres said. "The jelly part is like nothing we've 
seen before on Mars. It's very high in sulfur and magnesium and it has 
twice as much manganese as anything we've seen before. I don't know what 
any of this means. We're completely confused, everybody on the team is 
arguing and fighting. We're having a wonderful time!"

But that's the beauty of this mission, Squyres said.

"I used to have this comforting notion that at some point, we could sit 
back and say 'we did it, we're finished, we've learned everything we could 
about this location.' But Mars is not like that. It keeps throwing new 
things at us."

"And what I've come to realize," Squyres concluded," - and it was true 
when we lost Spirit and it will be true when we lose Opportunity - there 
will always be something tantalizing just beyond our reach that we just 
won't get to. That's just the nature of exploration, and I feel so very 
fortunate to have been part of this mission."