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Headshot of Bill Nye - Updated

Curiosity's Marsdial is on Mars!

Posted by Bill Nye

14-08-2012 16:24 CDT

Topics: Marsdials and Earthdials, pretty pictures, amateur image processing, Mars, Curiosity (Mars Science Laboratory)

Following the successful landing of the Curiosity rover, it is gratifying indeed to see the third MarsDial© photometric calibration (cal) target on the planet Mars. It is something near and dear to me personally, and it's good for all of us, because it helps us do good science.

As I'm sure you're aware, geologists love rocks, and they especially love the rocks on Mars. The first thing they all want to know about a rock is what's it made of. For that, it's good to just take a look at the color of the rock surface. When everything is being done on the alien landscape of another world, it's easy enough to electronically get the color wrong, or not quite right. To that end, artists, photographers, and a few scientists have noticed that by looking at the color of a shadow on a neutral white or gray background, you can infer the color contributed to the scene by the sky.

Curiosity Marsdial on Mars!

NASA / JPL / MSSS / Gordan Ugarkovic

Curiosity Marsdial on Mars!
Four Mastcam images of the calibration target -- the Marsdial -- were taken on Curiosity's sol 3 (August 9, 2012) over a period of about 8 minutes. In that time, the shadow of the gnomon moved slightly, marking time on Mars with a sundial.

On Earth, shadows take on a sky blue tinge (what I like to call "cerulescence"). On Mars, it's a salmon color (what I like to call "arangidescence"). And so, the MarsDials bear a small metal post that casts a shadow onto some white and gray rings of known value or grayness. In the coming weeks, we will electronically create some sundial-style hour lines on Curiosity's MarsDial. Along with good geology, we'll do some timekeeping with the Sun's apparent motion across an alien sky. Stay tuned for our upcoming parallel EarthDial project. We want people everywhere to do some sundialing to help know and appreciate our place in space.

See other posts from August 2012


Or read more blog entries about: Marsdials and Earthdials, pretty pictures, amateur image processing, Mars, Curiosity (Mars Science Laboratory)


dee34rt: 08/15/2012 03:05 CDT

Кажется, он показывает зубы.

RJHorn: 08/15/2012 11:32 CDT

Hi Bill, I'm a long time member and this was my 2nd conference attending in Pasadena. What fun and excitement for everybody! The roller-coaster ride on Sunday evening was intense until touch-down!! What a relief.... I'm so proud of NASA / JPL and the other countries that were involved. I'm also proud of the "Planetary Society" and have been since 1981 when Carl Sagan inspired me to join. I also see a new energy and direction since you took leadership. You're an inspiration to us all and getting the younger generation to take part in this adventure is awesome! We're heading into the future and I feel the momentum ~ Thank-you Bill Nye for your spirit, your humor and dedication to our cause! Sincerely, Ron Horn / Tucson, Arizona

Gkell1: 08/22/2012 09:55 CDT

Hi,it would be great to demonstrate the historical and technical development of Sundials/Earthdials in order to put the dial on Mars to good use and a proper explanation has yet to appear. Setting aside the great astronomical clocks of the Neolithic period,clocks which marked the solstices and equinoxes and even the lunar month,the first reference to annual and daily timekeeping was in relation to water,lots and lots of it as the Nile flooded every year on a particular day.The Egyptians noticed that they could not rely on a system of consecutive 365 days as the Nile flooded for 3 years on the same day but after another 365 days nothing happened until the next day,a day we now call the leap day of February 29th.It was then that the Egyptians looked for a celestial reference which mirrored this event and they found it in the brilliant star Sirius as it emerged from behind the glare of the Sun after a lengthy absence. It took another 1500 years before sundials entered the picture as the 24 hour AM/PM cycle emerged in tandem with the Lat/Long system.Of course there were many advancement between the calendar system and the average 24 hour day but the discovery that the Earth turns once a day and orbits the central Sun was crucial for turning days and years into their respective causes of rotations and orbital circuits of the Sun. To make sense of the motion of a shadow across a dial,whether it is that of the moving Earth or Mars, is complicated yet it is vital for explaining how sundials connect the raw dynamics of Earth and Mars into their respective timekeeping systems. We,therefore,have a chance to create a system for Mars from scratch and although it may appear simple at first,the development of a calendar system and the correspondence of Martian days with Martian years is as tricky as it is for the Earth.Despite appearances,this facet of the Curiousity mission is many times more important than any other and for many reasons and it focuses attention back on the development of timekeeping on Earth in tandem with the discovery of planetary dynamics and terrestrial effects of a moving Earth and on into such human achievements as the solving of the Longitude problem.

lk: 09/07/2012 12:18 CDT

Hello Bill! I've been a fanfor decades, thanks for the great work! I also worked for Woody at UW for 6 years, right through the Spirit and Opportunity years and now I am thrilled to see the Mars Dial on a 3rd rover! Keep looking up!

Fllancer2012: 10/30/2012 06:58 CDT

Bill, how can you incorporate the tremendous scientific revelations into our American classrooms and curriculums to teach our American children about the joy of scientific discovery?

david gash: 11/30/2012 10:44 CST

so thats what i'ts for, thanks Bill

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