With all of the attention that Curiosity has been getting, we might almost forget sometimes that there is still another rover elsewhere on the planet, Opportunity, which is still going strong – in its ninth year now!
When the Opportunity rover first landed on Mars in 2004, one of the first discoveries it made was that the ground was covered by tiny, round spherules up to a few millimetres in diameter. Also found imbedded in rock outcrops, they were an unexpected and fascinating surprise. What were they?
After extensive analysis by the rover, it was concluded by the scientists involved that they were concretions – little bb-like iron-oxide spherules similar to those found on Earth, notably those in the Navajo Sanstone deposits in Utah. The Martian ones also contain the mineral hematite, explaining the hematite signature seen in this region from orbit by the Mars Reconnaissance Orbiter spacecraft.
See Examiner.com for the full article.
The Opportunity rover has moved on a bit from Kirkwood, the previous rock outcrop with the new type of spherules in it that the scientists have taken so much interest in. It is now examining another odd-looking feature, a rather flat exposure of rock just a little to the north. Nicknamed Whitewater Lake, it is much lighter in colour than the surrounding rocks and soil and has a surface texture not seen before, sort of like stucco or plaster of Paris. Could it also be water or clay related? Only further analysis will hopefully provide some answers.
Next to Whitewater Lake is another interesting rock, nicknamed Errington, which is split into at least three large pieces and appears to be covered with the same tiny spherules first seen a bit farther south on the Kirkwood rock outcrop.
Is there a connection between these very different types of rock outcrops? They look so different but are so close together. Are they related to the clay deposits in the area? We should know more soon… Thanks again to Stuart Atkinson for use of his excellent mosaic images.
Addendum: the day after this article was posted, an official report about these oddities was posted by NASA here. Interesting!
One of the most interesting discoveries made so far by the Opportunity rover on Mars has been the small round spherules or “blueberries” as they are commonly referred to, covering the ground at the rover’s landing site. Typically only a few millimetres across, some lie loose on the soil while others are imbedded in rock outcrops.
Analysis by Opportunity indicates that they are most likely a type of concretion, which are also found on Earth. These Martian concretions have been found to contain the mineral hematite, which explains its detection in this region from orbit, and one of the main reasons that the rover was sent to this location in Meridiani Planum in the first place. They are similar to the Moqui Marbles, iron-oxide concretions in the outcrops of Navajo Sanstone in Utah, which formed in groundwater.
Now, the rover (eight years later and still going!) has found what may be a different type of spherule. These ones generally resemble the previous ones, but are quite densely packed in an unusual rock outcrop that is on the eastern side of Cape York, the small island-like ledge on the rim of the huge Endeavour crater. With brittle-looking “fins” of material, the outcrop is an an area that from orbit has been identified as containing small clay deposits. There are also more substantial clay deposits farther south along Endeavour’s rim at the much larger Cape Tribulation, the next major destination of Opportunity.
See Universe Today for the full article.
Although the Curiosity rover has been in the limelight the past few weeks, and for good reason, elsewhere on Mars the Opportunity rover continues its studies of the region around the rim of the huge Endeavour crater. Yes, she’s still there!
The rover is now in an area where clays have been identified from orbit, a prime target of the rover, as clays indicate a past watery environment which was non-acidic (ph neutral). It isn’t known exactly what these deposits might look like on the ground, but the rover is now investigating an interesting-looking outcrop of darker rock right in one of the clay deposit areas. Does it contain some of the long-sought clays? We don’t know yet, but it is still a curious-looking outcrop even if it doesn’t. It’s a mix of thin “fin-like” pieces, similar to others seen before in other locations, and other blocky chunks. Appearance-wise, it resembles dry, eroding clays on Earth.
The images in this post are courtesy of Stuart Atkinson, who does excellent work of stitching together individual images sent by the rover into more complete mosaics. Click on the two panoramas for larger versions. The last image is a 3-D anaglyph, so if you have 3-D glasses or other software, you can view it in even more realistic detail.
The Opportunity rover continues to explore Cape York, on the edge of the huge Endeavour crater, and has now arrived at a curious feature that many interested people have been wanting to see close-up – Whim Creek.
Whim Creek, as it is nicknamed, is a wedge-shape “cut” in the northern edge of Cape York. Whether it is a tectonic, impact or fluvial feature, or something else, isn’t known yet. There should be more images over the next few days as well.
A beautiful new panorama taken by the rover Opportunity on Mars shows the rover’s winter resting place where it waited out the colder temperatures and less power before resuming driving again a few weeks ago. The parking spot, nicknamed Greeley Haven, is an outcrop on the edge of the massive Endeavour crater.
The 360 degree view, taken with the rover’s Pancam camera, shows Greeley Haven, Endeavour, rover tracks and portions of the rover itself.
See Examiner.com for the full article.
When Opportunity first found the interesting mineral “veins” recently, the question of course was what were they made of? Were they the same as similar-looking veins on Earth? It turns out they are indeed similar and are composed of calcium sulfate – gypsum, specifically.
What does this mean? Basically, it is further evidence, and in the opinion of scientists involved, the best evidence to date for past water on Mars that was less acidic (more neutral) than water in some other areas. Such locations would have been more favourable for life.
According to Steve Squyres, principal investigator, “This tells a slam-dunk story that water flowed through underground fractures in the rock. This stuff is a fairly pure chemical deposit that formed in place right where we see it. That can’t be said for other gypsum seen on Mars or for other water-related minerals Opportunity has found. It’s not uncommon on Earth, but on Mars, it’s the kind of thing that makes geologists jump out of their chairs.”
The vein deposit, nicknamed Homestake, probably formed from rising groundwater dissolving calcium out of volcanic rocks. Dune fields of wind-blown gypsum have been seen before on Mars, but this deposit is believed to have formed right where it is. This and other similar veins have been found in the debris apron surrounding Endeavour crater which Opportunity is still studying, and is the first time they have ever been seen by either rover.
See also this excellent update from The Planetary Society.
Just a quick update to the previous post about the Homestake rock vein being investigated by Opportunity on Mars. Another great image from Stuart Atkinson (colour composite of individual NASA images) showing Homestake in its entirety. Larger version here. Details about its composition are still pending, but hopefully soon…