Mars rover news - Page 12

01101001 · #**331** (**permalink**) 25-October-2006, 08:11 PM

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Originally Posted by NASA

The overall panorama consists of 1,449 Pancam images [...]

yaohua2000 · #**332** (**permalink**) 25-October-2006, 10:19 PM

1000th sunrise at 2006-10-27 06:46 UTC;
1000th sunset at 2006-10-26 17:43 UTC.

ToSeek · #**333** (**permalink**) 31-October-2006, 07:07 PM

Mars Exploration Rovers Update:
New Milestones Set as Spirit Celebrates 1000 Sols, Opportunity Digs Victoria with a Little Help from a Friend

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The Mars Exploration Rovers managed to log another couple of significant milestones this month even as they worked in place, on autopilot, for the last two weeks during superior conjunction, the period that occurs every 2 years when Earth and Mars orbit into positions on opposite sides of the Sun, obscured from each other. With the conjunction now over, the rovers are slated to be back in command operation by tomorrow, All Hallow's Eve or, more popularly, Halloween.

mickal555 · #**334** (**permalink**) 05-November-2006, 10:20 PM

Wow- will they ever die!

Omicron Persei 8 · #**335** (**permalink**) 05-November-2006, 11:07 PM

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Originally Posted by mickal555

Wow- will they ever die!

Let's hope not!

Blob · #**336** (**permalink**) 14-November-2006, 01:23 AM

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OPPORTUNITY UPDATE: Opportunity on the Move after Solar Conjunction - sol 968-995, November 13, 2006:

Opportunity is healthy and has driven away from the "Cape Verde" promontory for further exploration around the rim of "Victoria Crater." Over the course of the next week, the rover will make its way clockwise around Victoria Crater to the next promontory, "Cape St. Mary." Opportunity will then image the northeast-facing cliff of Cape Verde to characterize lateral changes in layers of the crater wall. Along the way, Opportunity will be using the panoramic camera to scout a safe place to drive into the crater.
During the drive on Sol 992, rover planners performed the first step of the in-flight checkout of one of the rover's new technologies: visual target tracking (VTT). This first checkout included picking a target to track, driving, and testing the rover's knowledge of how its position changed relative to the target. The rover performed this activity as planned. The next step will be to execute a drive to a VTT target.
During the solar conjunction period from sol 970 to sol 984 (Oct. 16 to 30), Opportunity used its panoramic camera to image Victoria Crater from the Cape Verde promontory, collected 3.5 hours of Moessbauer spectrometer data each sol on the hole that the rock abrasion tool drilled at target "Cha," and performed its standard sol-to-sol atmospheric and remote sensing observations. Opportunity collected more than 50 hours of Moessbauer data on Cha.

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SPIRIT UPDATE: Spirit's 'Arm' Busy Checking New Targets - sol 1013-1016, November 13, 2006:

After Spirit's successful 0.71-metre bump on sol 1010, the team has new targets in the robotic arm's work volume for the first time in 204 sols. There is some interesting light and dark material within arm's reach and this week the team planned a robotic arm campaign including a microscopic imager mosaic, four hours of alpha particle X-ray spectrometer integration and 43 hours of Moessbauer spectrometer integration. Spirit is receiving a little over 320 Watt-hours now and is able to occasionally use the Moessbauer or alpha particle X-ray spectrometer overnight.

Squink · #**337** (**permalink**) 01-December-2006, 04:04 AM

Blueberry conglomerates at Gusev?
Sol 1031 microscopic images:
here and here

JonClarke · #**338** (**permalink**) 02-December-2006, 07:56 AM

No blueberries reported at Gusev, and the grains are 1 mm across or less. But it is certainly a cemented layer of coarse well rounded sand, as the navcam picture shows.

here

It's not clear whether it is an eroded indurated surface crust or a stratigraphic unit like a bed. I would incline to the second. It is certainly very interesting and a bit on the coarse side for an aeolian deposit. Maybe a lag or, if it is a bed in the bedrock, a waterlaid unit. Another possibility is that they could be small accretionary lapelli. this would be in keeping with the volcanic nature of some of the rocks seen in the area, like Home Plate.

Jon

01101001 · #**339** (**permalink**) 04-December-2006, 03:51 AM

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Originally Posted by Squink

Blueberry conglomerates at Gusev?

The December 3 Squyres Mission Update mentions this rock (and similar rounded grains studied earlier):

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The rock we've been looking at for the past couple of weeks is one called King George Island, and it's got some of the best-rounded grains we've ever seen in a martian rock. It's tempting to get very excited about grains that are that big and that round, until you remember that we know that the martian wind can transport and round off even bigger grains. Those of you with good memories will recall that we saw some really well rounded coarse granules in wind ripples out on the Gusev plains early in the mission. (One of them was named Serpent; there were several others.) So while we're not ready to jump to any big conclusions, King George Island sure is a cool-looking rock.

Squink · #**340** (**permalink**) 04-December-2006, 05:56 PM

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Squyres:
It's tempting to get very excited about grains...

Yes, yes it is. The gleam off some of them is very hematite like. Presumably they've done mini-tess, and will eventually let us know.

Nicolas · #**341** (**permalink**) 04-December-2006, 06:33 PM

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Squyres:
It's tempting to get very excited about grains...

The question is though, would you get excited enough about grain to keep quiet when your old enemy is telling a big bold lie about going to the moon?

01101001 · #**342** (**permalink**) 15-December-2006, 07:34 AM

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, E12S12, doi:10.1029/2006JE002771, 2006

Overview of the Opportunity Mars Exploration Rover Mission to Meridiani Planum: Eagle Crater to Purgatory Ripple

S. W. Squyres, et al

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Abstract
The Mars Exploration Rover Opportunity touched down at Meridiani Planum in January 2004 and since then has been conducting observations with the Athena science payload. The rover has traversed more than 5 km, carrying out the first outcrop-scale investigation of sedimentary rocks on Mars. The rocks of Meridiani Planum are sandstones formed by eolian and aqueous reworking of sand grains that are composed of mixed fine-grained siliciclastics and sulfates. The siliciclastic fraction was produced by chemical alteration of a precursor basalt. The sulfates are dominantly Mg-sulfates and also include Ca-sulfates and jarosite. The stratigraphic section observed to date is dominated by eolian bedforms, with subaqueous current ripples exposed near the top of the section. After deposition, interaction with groundwater produced a range of diagenetic features, notably the hematite-rich concretions known as “blueberries.” The bedrock at Meridiani is highly friable and has undergone substantial erosion by wind-transported basaltic sand. This sand, along with concretions and concretion fragments eroded from the rock, makes up a soil cover that thinly and discontinuously buries the bedrock. The soil surface exhibits both ancient and active wind ripples that record past and present wind directions. Loose rocks on the soil surface are rare and include both impact ejecta and meteorites. While Opportunity's results show that liquid water was once present at Meridiani Planum below and occasionally at the surface, the environmental conditions recorded were dominantly arid, acidic, and oxidizing and would have posed some significant challenges to the origin of life.

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, E12S10, doi:10.1029/2006JE002754, 2006

Erosion rates at the Mars Exploration Rover landing sites and long-term climate change on Mars

M. P. Golombek, et al

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Abstract
Erosion rates derived from the Gusev cratered plains and the erosion of weak sulfates by saltating sand at Meridiani Planum are so slow that they argue that the present dry and desiccating environment has persisted since the Early Hesperian. In contrast, sedimentary rocks at Meridiani formed in the presence of groundwater and occasional surface water, and many Columbia Hills rocks at Gusev underwent aqueous alteration during the Late Noachian, approximately coeval with a wide variety of geomorphic indicators that indicate a wetter and likely warmer environment. Two-toned rocks, elevated ventifacts, and perched and undercut rocks indicate localized deflation of the Gusev plains and deposition of an equivalent amount of sediment into craters to form hollows, suggesting average erosion rates of ∼0.03 nm/yr. Erosion of Hesperian craters, modification of Late Amazonian craters, and the concentration of hematite concretions in the soils of Meridiani yield slightly higher average erosion rates of 1–10 nm/yr in the Amazonian. These erosion rates are 2–5 orders of magnitude lower than the slowest continental denudation rates on Earth, indicating that liquid water was not an active erosional agent. Erosion rates for Meridiani just before deposition of the sulfate-rich sediments and other eroded Noachian areas are comparable with slow denudation rates on Earth that are dominated by liquid water. Available data suggest the climate change at the landing sites from wet and likely warm to dry and desiccating occurred sometime between the Late Noachian and the beginning of the Late Hesperian (3.7–3.5 Ga).

Other papers from AGU JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, 2006 Special Section:
Results From the Mars Exploration Rover Opportunity Mission
Results From the Mars Exploration Rover Spirit Mission

Cugel · #**343** (**permalink**) 15-December-2006, 09:37 AM

an erosion rate of ∼0.03 nm/yr ???
what is that unit?
nautical miles per year?
nanometers?

Laguna2 · #**344** (**permalink**) 15-December-2006, 10:06 AM

Quote:

Originally Posted by Cugel

an erosion rate of ∼0.03 nm/yr ???
what is that unit?
nautical miles per year?
nanometers?

I would guess nanometers

Cugel · #**345** (**permalink**) 15-December-2006, 03:17 PM

If it is nanometer it means an average erosion rate of 3 cm per billion years.
(there are 1,000,000,000 nanometers in a meter, give or take a few...)
Wow.
I think it is a (double) typo, and they actually mean mm/yr.

01101001 · #**346** (**permalink**) 15-December-2006, 03:45 PM

Quote:

Originally Posted by Cugel

If it is nanometer it means an average erosion rate of 3 cm per billion years. (there are 1,000,000,000 nanometers in a meter, give or take a few...) Wow. I think it is a (double) typo, and they actually mean mm/yr.

I think Golembek meant what appeared there.

His earlier Pathfinder estimates were just slightly higher in CLIMATE CHANGE ON MARS INFERRED FROM EROSION RATES AT THE MARS PATHFINDERLANDING SITE (PDF):

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These observations and calculations severely
limit the erosion or deflation of materials at the Pathfinder
and Viking 1 landing sites to <1 nm/yr and more likely
<0.1 nm/yr or mm/Ma or m/Ga in the past 1.8-3.5 Ga at
the Pathfinder site and suggests that a cold and dry
environment, similar to today's, has prevailed since that
time.

Romanus · #**347** (**permalink**) 15-December-2006, 04:14 PM

3 cm per billion years?

That's the Moon, for all intents and purposes...

01101001 · #**348** (**permalink**) 15-December-2006, 05:16 PM

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Originally Posted by Romanus

3 cm per billion years?

Just another confirmatory brush with the number Golombek has arrived at: Science Magazine, Letter and Response, Wind and Climate on Mars (PDF)

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The direct evidence outlined in my [1999, Pathfinder and Viking] Perspective is that remarkably little has occurred at the site since it was deposited by catastrophic floods, and thus the long-term rate of change is remarkably slow (of order 0.01 nm/year).