Abe Lincoln Has Mars Dust In His Beard

After 14 months on Mars, Curiosity 1909 Lincoln cent is covered in a fine patina Martian dust and bits of soil. Photo taken on Oct. 2, 2013. Click to enlarge. Credit: NASA/ JPL-Caltech

When the Curiosity rover landed on Mars more than a year ago it brought with it an earthly artifact more than a century old – a 1909 Lincoln penny. For good luck? Maybe, but JPL engineers affixed the penny to the roving robot as a calibration target for its mobile, closeup camera named MAHLI (Mars Hand Lens Imager). While Abe’s looking a little dusty, his weathered face tells the story of 14 months on another planet.

The calibration target used by MAHLI to correct color casts in photos. The penny serves as a size reference. Credit: NASA/ JPL-Caltech

For MAHLI’s closeup pictures to accurately portray colors and brightness of the Martian landscape it needs a reference. The colored patches allow MAHLI to “white balance” or neutralize color casts common in digital images. The penny is a nod to the common practice by geologists of placing an object of known size in the frame to give the viewer a sense of scale.

Without something familiar in a picture as a reference, it’s hard to know the dimensions of things like soil grains and Mars pebbles.

Ken Edgett, principal investigator for MAHLI, bought the penny with his own money (coins in similar condition go for around $20 on eBay). Sure, mission planners could have used a standard ruler scale but opted instead for Edgett’s more poetic penny. NASA’s willingness to bend standard procedure to better connect with the public is a good thing.

The Mars penny all shiny before launch (left) and on Oct. 2. The coin is a 1909 VDB cent. The initials “VDB” of the coin’s designer, Victor David Brenner, are etched onto the reverse side. Credit: NASA/JPL-Caltech

But why a 1909 penny in particular? The Lincoln cent was first minted in 1909 to commemorate the centennial of President Lincoln’s birth. Curiosity was originally scheduled to launch in 2009, which happened to be the penny’s 100th anniversary. The connections across 200 years of time have an irresistible appeal to our romantic side.

Location of the calibration target and penny on the Curiosity rover. Credit: NASA

Delays pushed Curiosity’s launch date to 2011, but Lincoln kept his seat and now looks out across new territory every day.

The penny’s shine has disappeared beneath a fine coating of dust and bits of soil. I imagine NASA scientists wringing crucial data about the Martian atmosphere, winds and soil particle size as they study of the deposition of material on the coin’s face now and in the years ahead. Lincoln’s legacy reaches even to the Red Planet.

9 Responses

  1. Ej

    They picked a 1909 vbs bcs it’s the rarest wheat penny I’m assuming. There worth 100s of dollars. Regular 1909 a without the vbs are only worth a few cents

  2. Common Scents

    Bob is right, the 09 plain cent is not rare, however, if this penny ever made it back to Earth, I can assure you, it’s value would “skyrocket.” Get it? Skyrocket? But seriously, it would be something most any collector, coins or otherwise, would want. I would, just for what it’s seen and where it’s been.

  3. robin k.

    hi bob. i’m posting here, because i am asking about something i saw in the sky on the night of 10/5. maybe you can tell me what i was seeing from my description? i was in an area with no city lights, in upstate new york, at about 11:00 p.m. the sky was very dark and overcast, except for a wide band of light brown/ orange-brown across the horizon. i’m wondering what that band of color was … if it helps, it was fairly humid at the time. thank you! robin in n.y.

    1. astrobob

      It sounds to me like the glow of city lights (sodium vapor lights in particular since they’re orange) in humid or hazy air.

  4. Giorgio Rizzarelli

    Good to know that Curiosity is posting (raw) pics on the rover site, despite the human updating of the site is blocked by the gov shutdown (the rover is “essential personnel” LOL she can even autodrive). Good idea looking there Bob, it suggested me to watch more raw pics, which I didn’t since quite a while, there are some excelllent already in raw form and it’s fun to elaborate some by ourselves. Excellent news that new missions Maven and Ladee are proceeding despite the shutdown.

    1. astrobob

      Yes, lots of good news despite the shutdown. Lots of interesting things to find in the raw images. I also keep checking there in case NASA posts additional ISON photos taken by Curiosity.

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