From NASA JPL: NASA Mars Rover Views Eclipse of the Sun by Phobos
PASADENA, Calif. – Images taken with a telephoto-lens camera on NASA’s Mars rover Curiosity catch the larger of Mars’ two moons, Phobos, passing directly in front of the sun — the sharpest images of a solar eclipse ever taken at Mars.
Phobos does not fully cover the sun, as seen from the surface of Mars, so the solar eclipse is what’s called a ring, or annular, type.
This set of three images shows views three seconds apart as the larger of Mars’ two moons, Phobos, passed directly in front of the sun as seen by NASA’s Mars rover Curiosity. Curiosity photographed this annular, or ring, eclipse with the telephoto-lens camera of the rover’s Mast Camera pair (right Mastcam) on Aug. 17, 2013, the 369th Martian day, or sol, of Curiosity’s work on Mars. Image credit: NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ. › Full image and caption
A set of three frames from Curiosity’s Mast Camera (Mastcam), taken three seconds apart as Phobos eclipsed the sun, is at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17356 .
The images are the first full-resolution frames downlinked to Earth from an Aug. 17, 2013, series. The series may later provide a movie of the eclipse. Curiosity paused during its drive that day to record the sky-watching images.
“This event occurred near noon at Curiosity’s location, which put Phobos at its closest point to the rover, appearing larger against the sun than it would at other times of day,” said Mark Lemmon of Texas A&M University, College Station, a co-investigator for use of Curiosity’s Mastcam. “This is the closest to a total eclipse of the sun that you can have from Mars.”
Observations of the Martian moons, Phobos and Deimos, by Curiosity and by the older, still-active Mars rover Opportunity are helping researchers get more precise knowledge of the moons’ orbits. During the Aug. 17 observation, the position of Phobos crossing the sun was a mile or two (two or three kilometers) closer to the center of the sun’s position than researchers anticipated.
Lemmon said, “This one is by far the most detailed image of any Martian lunar transit ever taken, and it is especially useful because it is annular. It was even closer to the sun’s center than predicted, so we learned something.”
NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, manages the Mars Science Laboratory Project for NASA’s Science Mission Directorate, Washington. JPL designed and built the project’s Curiosity rover.
Malin Space Science Systems, San Diego, built and operates the Mastcam instrument and two other instruments on Curiosity.
More information about Curiosity is online at http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at http://www.facebook.com/marscuriosity and on Twitter at http://www.twitter.com/marscuriosity .
During the Aug. 17 observation, the position of Phobos crossing the sun was a mile or two (two or three kilometers) closer to the center of the sun’s position than researchers anticipated.
If planetary geometry isn’t as settled a science as they thought, what chance does climatology have?
its not an eclipse…more like a transit…nice technical tour de force though
Cool!
Now tell us what it really is.
Interesting. Phobos is only about 20 miles wide at its biggest as opposed to 2000 for our Moon, so the whole concept is far different for Mars than Earth. And whoever knew to calculate the upcoming eclipse/transit really knew their stuff; the eclipse track on the surface of Mars must have been about the same as a two-lane road.
“During the Aug. 17 observation, the position of Phobos crossing the sun was a mile or two (two or three kilometers) closer to the center of the sun’s position than researchers anticipated.”
I take it that Phobos in its orbit was a mile or two north or south of the position that had been calculated for it. If Phobos is about 20 miles wide at its biggest, then the diameter of an object that would have exactly covered the view of the sun would have been about 30 miles. Hence from a location where the top edge of Phobos just touched the sun’s top edge to where the bottom edges coincided would have been about 15 miles. So the track of the ‘annular’ eclipse would also have been about 15 miles wide.
Slightly off this topic, there can be not only an annular eclipse of the sun by the moon as seen on earth, there can also be an annular eclipse of the sun by the earth as seen on the moon. I leave that to contributors to try to figure that out.
Phobos was covering a lot more of the Sun than I expected. Lessee, the Sun’s size is smaller than from Earth, but the big item is Phobos orbits at only 9,300 km above Mars, so that explains most of what’s happening. http://solarsystem.nasa.gov/planets/compchart.cfm
Deimos is smaller and farther away, but ultimately more fun, see my old The Great Escape of The Martian Festival summary of events held there.
Bloke down the pub says: August 30, 2013 at 6:11 am “During the Aug. 17 observation, the position of Phobos crossing the sun was a mile or two (two or three kilometers) closer to the center of the sun’s position than researchers anticipated. If planetary geometry isn’t as settled a science as they thought, what chance does climatology have?”
That’s about three parts in 2 x 10^8?
Dudley Horscroft says:
August 30, 2013 at 6:52 am
Trick question, I’m sure, but I assume the answer involves seeing the very distant sunrise and sunset while the Sun is below the horizon….
I especially love working with kids who are also on the Autism Spectrum Disorder scale. I have very fond memories of two boys, both on the high intelligence part of the multilayer spectrum but who had lots of difficulties with social and sensory issues. But, put them in front of a science task and they sang like nightingales. One of their favorite research and writing topics was to choose a moon in our solar system to study. One boy chose Phobos, and the other chose Saturn’s very interesting moon Enceladus (among a plethora of interesting moons).
I have discovered something very important about the excitement of new learning in these children. They don’t have preconceived or “pet theories”. All things are studied with equal open eyes, logic is used as the key to separate myth from fact from opinion and everything is given equal intelligent treatment. I remember the unemotional response to learning about the early history of belief of human-like development on Phobos. These boys see regular and irregular shapes in everyday life ALL THE TIME and do not ascribe human origins to them as their first thought. So learning about the “object” on Phobos and the initial media response to it was readily dealt with in Autism style. Without nasty ridicule, or derision, it was discussed and dealt with using that wonderfully dry intelligent conversation that often describes kids on the spectrum. It comes off rudely if you are not on the spectrum because myth and opinion are swiftly and logically dealt with so well that people often have difficulty responding to it, but to me the pure logic of their reasoning is ear candy.
So if you have a pet theory not well founded in observation and fact, and happen to come upon a grown up version of these two boys, be prepared to have your pet theory dryly, quickly, and completely cut to shreds.
Maybe Anthony enrolled his daughter to document this one too?
I’d put “eclipse” in quotations. I understand that Anthony is alluding to a moon moving in front of the sun and for the sake of the HEADLINE liberties can be taken.
Transit is the appropriate term of art I believe.
Pamela – what a wonderful description of the thinking power of these marvellous kids! Tell them that out there, there is one albeit ageing professor who is full of admiration for what they do.
Pamela Gray: IOW, the Sheldon Cooper treatment.
@Dudley Horsecroft:
The angular diameter of the sun as seen from the moon is 31.6′ – 32.7′.
The angular diameter of the earth as seen from the moon is 54.0′-72.2′.
No annular eclipse of the sun by earth as seen from the moon.
It’s actually close-up pictures of the eyes of the Tumblr “FUUUUUUUUUUU” guy.
See here; 😉
http://www.fuuuucomics.com/2009/12/there-is-one-k-fuuuu/
@Pamela Gray: You have just described in essence almost every discussion I (a chemist) have with my brother Jim (the mathematician) and/or my brother Bill (the physicist).
Pamela,
Almost missed a photo of the 1994 annular solar eclipse while the elementary school kids watched it through my telescope. Happened to be in a location where I was about 30 miles north of dead center so took the rig to the local Catholic school. Many of the kids loved it. No longer live in that area and often wonder how many of those now grown up kids might now be into astronomy. Interesting that some were wowed by it with tons of questions and others had very little to no interest.
Pamela Gray said:
August 30, 2013 at 7:28 am
I especially love working with kids who are also on the Autism Spectrum Disorder scale.
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Lovely post – TY! 🙂
NASA. One side dazzling us with stuff like this, the other making a mockery of our intelligence.
Ahh, the annular, diamond ring.
On Earth it represents the Sun-god (Ra, Helios, Sol) caught in flagrante delicto with the Moon-goddess (Isis, Selene, Lunar). And their love was sealed with a diamond ring.
http://minaday.com/movies/wp-content/uploads/2011/05/diamond-ring-eclipse2.png
The old cosmic religions were much more interesting. Who needed a soap opera?
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Pamela,
I have a son who is on the spectrum. I often describe his thinking as “unconditional.”
As a scientist myself, I can appreciate this clear view of the world. I am glad to hear that you appreciate this perspective, too.
Amazing photograph, very impressed that this could have been predicted as it looks like Phobos crosses the suns disc in under ten seconds!
I hope to one day live to see man set foot on the planet, but these photographs are awesome in themselves!
So brilliant hued the wonderous Sun
Of diamonds brighter there are none
Atmosphere.
Wow, the images sure leave no doubt that Phobos is irregularly
shaped (as is true for most smaller moons). I have heard that
there is a certain limiting diameter; celestial objects greater than
that diameter are at least roughly spherical; below, they can be
very irregular. I wonder if someone’s name is attached to it,
as in the Roche limit or Chandrasekhar’s limit?