NASA’s Curiosity rover will skip drilling into a possible 4th rock target and instead resume the trek to Mount Sharp after finding it was unfortunately a slippery rock at the edge of a Martian valley of slippery sands and was therefore too risky to proceed with deep drilling and interior sampling for chemical analysis.
After pounding into the “Bonanza King” rock outcrop on Wednesday, Aug. 20, to evaluate its potential as Curiosity’s 4th drill target on Mars and seeing that it moved on impact, the team decided it was not even safe enough to continue with the preliminary ‘mini-drill’ operation that day.
“We have decided that the rocks under consideration for drilling, based on the tests we did, are not good candidates for drilling,” said Curiosity Project Manager Jim Erickson of NASA’s Jet Propulsion Laboratory, Pasadena, California, in a statement.
“Instead of drilling here, we will resume driving toward Mount Sharp.”
Bonanza King was an enticing target because the outcrop possessed thin, white, cross-cutting mineral veins which could indicate that liquid water flowed here in the distant past. Water is a prerequisite for life as we know it.
Loose, unstable rocks pose a prospective hazard to the 1 ton robots hardware and health if they become dislodged during impact by the percussive drill located at the end of the robotic arm.
It’s worth recalling that whirling rocks during the nailbiting Red Planet touchdown two years ago on Aug. 6, 2012, inside Gale Crater are suspected to have slightly damaged Curiosity’s REMS meteorological instrument station.
Each drill target must pass a series of tests. And the prior three at more extensive outcrops all met those criteria. By comparison, imagery showed Bonanza King was clearly part of a much smaller outcrop. See our Bonanza King photo mosaics herein.
“One step in the procedure, called “start hole,” uses the hammering action of the percussive drill to create a small indentation in the rock. During this part of the test, the rock moved slightly, the rover sensed that instability in the target, and protective software properly halted the procedure,” according to a NASA statement.
This pale, flat Martian rock thus failed to pass the team’s safety criteria for drilling when it budged.
Bonanza King sits in an bright outcrop on the low ramp at the northeastern end of a spot leading in and out of an area called “Hidden Valley” which lies between Curiosity’s August 2012 landing site in Gale Crater and her ultimate destinations on Mount Sharp which dominates the center of the crater.
Just days ago, the rover team commanded a quick exit from “Hidden Valley” to backtrack out of the dune filled valley because of fears the six wheeled robot could get stuck in slippery sands extending the length of a football field.
“Hidden Valley” looked like it could turn into “Death Valley.”
As Curiosity tested the outcrop, the rover team was simultaneously searching for an alternate safe path forward to the sedimentary layers of Mount Sharp because she arrived at Hidden Valley after recently driving over a field of sharp edged rocks in the “Zabriskie Plateau” that caused further rips and tears in the already damaged 20 inch diameter aluminum wheels.
It will take a route skirting the north side of the sandy-floored valley taking care to steer away from the pointiest rocks.
“After further analysis of the sand, Hidden Valley does not appear to be navigable with the desired degree of confidence,” Erickson said. “We will use a route avoiding the worst of the sharp rocks as we drive slightly to the north of Hidden Valley.”
To date, Curiosity’s odometer totals over 5.5 miles (9.0 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 179,000 images.
Curiosity still has about another 2 miles (3 kilometers) to go to reach the entry way at a gap in the treacherous sand dunes at the foothills of Mount Sharp sometime later this year.
Hidden Valley gives a foretaste of the rippely slippery sand dune challenges lurking ahead!
Mount Sharp is a layered mountain that dominates most of Gale Crater and towers 3.4 miles (5.5 kilometers) into the Martian sky and is taller than Mount Rainier.
“Getting to Mount Sharp is the next big step for Curiosity and we expect that in the Fall of this year,” Dr. Jim Green, NASA’s Director of Planetary Sciences at NASA Headquarters, Washington, DC, told me in an interview marking the 2nd anniversary since touchdown on Aug. 6.
“Drilling on the crater floor will provide needed geologic context before Curiosity climbs the mountain.”
The team may go back to its original plan to drill at the potential science destination known as “Pahrump Hills” which was changed due to the route change forced by the slippery sands in Hidden Valley.
Read an Italian language version of this story by my imaging partner Marco Di Lorenzo – here
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