APOD: Curiosity Rover Takes Selfie on Mars (2017 Nov 20)

[APOD Robot]

Curiosity Rover Takes Selfie on Mars

Explanation: Yes, but have you ever taken a selfie on Mars? The Curiosity rover on Mars has. This selfie was compiled from many smaller images -- which is why the mechanical arm holding the camera is not visible. (Although its shadow is!) Taken in mid-2015, the featured image shows not only the adventurous rover, but dark layered rocks, the light colored peak of Mount Sharp, and the rusting red sand that pervades Mars. If you look closely, you can even see that a small rock is stuck into one of Curiosity's aging wheels. Now nearing the end of 2017, Curiosity continues to explore the layers of sedimentary rocks it has discovered on Vera Rubin Ridge in order to better understand, generally, the ancient geologic history of Mars and, specifically, why these types of rocks exist there.

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[heehaw]

We've come a long way from Mariner 4 ! https://en.wikipedia.org/wiki/Mariner_4

[Indigo_Sunrise]

Very interesting image. As far as the "small rock... stuck into one of Curiosity's aging wheels", is it the right front wheel? The enlarged image shows what looks like several holes that've been punched in the wheel: one towards the upper portion where the tread sorta zig-zags, and the other on the bottom, where it looks as though the ground can be seen. And the wheel directly behind that front one looks like it has a hole in it as well. Or is one of those spots the rock?

And wouldn't it be awesome if Curiosity lasted as long as Cassini?

[rj rl]

I'm surprised all those holes aren't absolutely full of rocks after 5 years of work.

[neufer]

And wouldn't it be awesome if Curiosity lasted as long as Cassini?

• Why not MER-B:

<<Opportunity, also known as MER-B (Mars Exploration Rover – B) or MER-1, is a robotic rover active on Mars since 2004. Launched on July 7, 2003 as part of NASA's Mars Exploration Rover program, it landed in Meridiani Planum on January 25, 2004, three weeks after its twin Spirit (MER-A) touched down on the other side of the planet. With a planned 90 sol duration of activity (slightly more than 90 earth days), Spirit functioned until getting stuck in 2009 and ceased communications in 2010, while Opportunity remains active as of November 17, 2017, having already exceeded its operating plan by 13 years, 205 days (in Earth time). Opportunity has continued to move, gather scientific observations, and report back to Earth for over 50 times its designed lifespan. As of August 7, 2017, the rover had traveled 44.97 kilometers. This date was mission time of Sol 4793.>>

[Chris Peterson]

We've come a long way from Mariner 4 ! https://en.wikipedia.org/wiki/Mariner_4

Mariner 4 was closer in time to when Burroughs was writing his Barsoom novels than it is to now.

[neufer]

We've come a long way from Mariner 4 ! https://en.wikipedia.org/wiki/Mariner_4

Mariner 4 was closer in time to when Burroughs was writing his Barsoom novels than it is to now.

And closer in time to the Wright brothers for that matter.

Which all goes to show that both hot wars and cold ones
advance technology at an accelerated pace unmatched in times of peace.

[rstevenson]

I'm curious why this mid-2015 image was chosen for an APOD now. There is a more recent selfie, published in May 2017 -- otherwise similar but taken part way up Mount Sharp -- that I assume could have been used.

Rob

[geckzilla]

We've come a long way from Mariner 4 ! https://en.wikipedia.org/wiki/Mariner_4

Mariner 4 was closer in time to when Burroughs was writing his Barsoom novels than it is to now.

And closer in time to the Wright brothers for that matter.

Which all goes to show that both hot wars and cold ones
advance technology at an accelerated pace unmatched in times of peace.

Let us never underestimate the power of motivation.

[De58te]

Technically Burroughs' Princess of Mars was already written in 1912 when it was serialized in a magazine, but since you said the novels, you are correct since they were published from 1916 to around 1947. But it depends what you mean by Wright Brothers? Assuming the first airplane powered flight at Kitty Hawk between 1903 -1904 then Mariner 4 is still closer to us. 1904 - July, 1965 - 2017.

[neufer]

Technically Burroughs' Princess of Mars was already written in 1912 when it was serialized in a magazine, but since you said the novels, you are correct since they were published from 1916 to around 1947. But it depends what you mean by Wright Brothers? Assuming the first airplane powered flight at Kitty Hawk between 1903 -1904 then Mariner 4 is still closer to us. 1904 - July, 1965 - 2017.

Mariner 4 would have been pure fantasy for Burroughs.

Curiosity, however, is a simple extension of Mariner 4 technology.

No one who watched Apollo 11 would have believed that we would not have manned colonies on Mars by 2017.

[Joe Stieber]

As far as the "small rock... stuck into one of Curiosity's aging wheels", is it the right front wheel? ... And the wheel directly behind that front one looks like it has a hole in it as well. Or is one of those spots the rock?

On right-middle wheel (especially in the enlarged view), I see a small rock sticking up from the upper edge on the right. That same wheel seems to be the aim point in the "Curiosity's aging wheels" link.

[ta152h0]

Wheels on Mars. Ever consider an arachnid type of propulsion on Mars ?

[Steve Dutch]

Why go to Mars? Because the rovers are awesome pieces of engineering, but a human geologist, on foot, in a spacesuit, would have been to the top of Mount Sharp by now.

[neufer]

Why go to Mars?
Because the rovers are awesome pieces of engineering,
but a human geologist, on foot, in a spacesuit,
would have been to the top of Mount Sharp by now.

• The bear went over the mountain,
  The bear went over the mountain,
  The bear went over the mountain,
  To see what he could see.
  And all that he could see,
  And all that he could see,
  Was the other side of the mountain,
  The other side of the mountain,
  The other side of the mountain,
  Was all that he could see.

[Wye Knot]

Wheels on Mars. Ever consider an arachnid type of propulsion on Mars ?

Yes, et al.

Other rover designs that do not use wheeled approaches are possible. Mechanisms that utilize "walking" on robotic legs, hopping, rolling, etc. are possible. For example, Stanford University researchers have proposed "Hedgehog", a small cube-shaped rover that can controllably hop—or even spin out of a sandy sinkhole by corkscrewing upward to escape—for surface exploration of low gravity celestial bodies

https://en.wikipedia.org/wiki/Rover_(space_exploration)

[neufer]

---

Wheels on Mars.

Ever consider an arachnid type of propulsion on Mars ?

We've already had Martian rover wheels seize up forcing the rover to drive backwards.

If a rove arachnid leg went limp or got snagged under a rock
would you have the rover bite its own leg off

[JohnD]

Holes in the wheels? Yes. View the enlarged image (left click on it and the when the cursor shows a +).
I can count at least seven holes where daylight shows through, so as we can see less than half a circumference, there are likely to be at least twice as as many.
This has been noted before and was the object of some media concern earlier this year: http://www.sciencemag.org/news/2017/03/ ... ife-crisis But NASA insist that it will not impair Curiosity's working life.
The wheels were each machined out of billet aluminium, so could have been any shape or thickness, and the unraised parts of the 'tread' are "less than the thickness of a dime" (Doesn't help me but will I'm sure, most readers) The secret of success in many fields is "Just add lightness" (Colin Chapman of Lotus, but his cars were notorious for breaking). Let's hope Curiosity will get to the chequered flag.
John

[neufer]

The wheels were each machined out of billet aluminium, so could have been any shape or thickness, and the unraised parts of the 'tread' are "less than the thickness of a dime" (Doesn't help me but will I'm sure, most readers).

<<The dime is the smallest in diameter and is the thinnest of all U.S. coins currently minted for circulation, being 17.91 mm in diameter and 1.35 mm in thickness. The word dime comes from the French word dîme, meaning "tithe" or "tenth part", from the Latin decima [pars]. The Coinage Act of 1792 established the dime (spelled "disme" in the legislation), cent, and mill. as subdivisions of the dollar equal to  1⁄10,  1⁄100 and  1⁄1000 dollar respectively. The first known proposal for a decimal-based coinage system in the United States was made in 1783 by Thomas Jefferson, Benjamin Franklin, Alexander Hamilton, and David Rittenhouse. Hamilton, the nation's first Secretary of the Treasury, recommended the issuance of six such coins in 1791, in a report to Congress. Among the six was a silver coin, "which shall be, in weight and value, one tenth part of a silver unit or dollar".

From 1796 to 1837, dimes were composed of 89.24 percent silver and 10.76 percent copper, the value of which required the coins to be physically very small to prevent their intrinsic value being worth more than face value. Thus dimes are made small and thin. The silver percentage was increased to 90.0 percent with the introduction of the Seated Liberty dime; the use of a richer alloy was offset by reducing the diameter from 18.8 millimeters to its current figure of 17.9 millimeters. With the passage of the Coinage Act of 1965, the dime's silver content was removed. Dimes from 1965 to the present are composed of outer layers of 75 percent copper and 25 percent nickel, bonded to a pure copper core. As of 2011, the dime coin cost 5.65 cents to produce.>>

[JohnD]

Thank you, Art, ever the clarifier!
John

[Indigo_Sunrise]

As far as the "small rock... stuck into one of Curiosity's aging wheels", is it the right front wheel? ... And the wheel directly behind that front one looks like it has a hole in it as well. Or is one of those spots the rock?

On right-middle wheel (especially in the enlarged view), I see a small rock sticking up from the upper edge on the right. That same wheel seems to be the aim point in the "Curiosity's aging wheels" link.

D'oh!
Now that you've pointed it out, it's pretty obvious - thank you!

[geckzilla]

Why go to Mars? Because the rovers are awesome pieces of engineering, but a human geologist, on foot, in a spacesuit, would have been to the top of Mount Sharp by now.

But if the geologist's foot gets a hole in it, she dies.

[Chris Peterson]

Why go to Mars? Because the rovers are awesome pieces of engineering, but a human geologist, on foot, in a spacesuit, would have been to the top of Mount Sharp by now.

Maybe. But to what purpose? The rovers are better geologists than geologists. For the most part, a human geologist on Mars isn't much better than the lab they are able to bring with them... just like the rovers. And most of the time they'll be busy keeping the toilets working, not doing science. Just like all manned spaceflight.

For what a single manned mission to Mars costs we could send hundreds of rovers, each working endlessly on returning valuable science.

[neufer]

Why go to Mars? Because the rovers are awesome pieces of engineering, but a human geologist, on foot, in a spacesuit, would have been to the top of Mount Sharp by now.

But if the geologist's foot gets a hole in it, she dies.

(Is Mount Sharp really that sharp )

Actually, dying would be the least of the problems.

More likely: there would be some emergency that required a rescue mission costing tens of billions of dollars.