Phobos rising and Earth setting as captured together by Curiosity
Cool image time! The picture to the right, enhanced and reduced to post here, was taken by the high resolution camera on the Mars rover Curiosity on September 5, 2024.
What makes this picture unique are the two tiny spots near the upper right. For the first time, Curiosity’s camera was able to capture both the Earth and the Martian moon Phobos in the same picture, when they were also very close to each other in the sky. From the caption:
NASA’s Curiosity Mars rover used its Mast Camera, or Mastcam, to capture this view of Earth setting while Phobos, one of Mars’ two moons, is rising. It’s the first time an image of the two celestial bodies have been captured together from the surface of Mars.
The image is a composite of five short exposures and 12 long exposures all taken on Sept. 5, 2024, the 4,295th Martian day, or sol, of Curiosity’s mission. An inset in the image [found here] shows Phobos on the left and Earth on the right. From the rover’s perspective, the inset area would be about half the width of a thumb held at arm’s length.
The dark shape in the lower left is one of the buttes that surround Curiosity as it has been climbing up Mount Sharp and traversing inside the Gediz Vallis slot canyon.
The inset provides a close-up of the two objects, but the resolution is poor. To me, it is much more interesting to look at the picture to the right, that shows what these two objects actually looked like in the sky of Mars.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Cool image time! The picture to the right, enhanced and reduced to post here, was taken by the high resolution camera on the Mars rover Curiosity on September 5, 2024.
What makes this picture unique are the two tiny spots near the upper right. For the first time, Curiosity’s camera was able to capture both the Earth and the Martian moon Phobos in the same picture, when they were also very close to each other in the sky. From the caption:
NASA’s Curiosity Mars rover used its Mast Camera, or Mastcam, to capture this view of Earth setting while Phobos, one of Mars’ two moons, is rising. It’s the first time an image of the two celestial bodies have been captured together from the surface of Mars.
The image is a composite of five short exposures and 12 long exposures all taken on Sept. 5, 2024, the 4,295th Martian day, or sol, of Curiosity’s mission. An inset in the image [found here] shows Phobos on the left and Earth on the right. From the rover’s perspective, the inset area would be about half the width of a thumb held at arm’s length.
The dark shape in the lower left is one of the buttes that surround Curiosity as it has been climbing up Mount Sharp and traversing inside the Gediz Vallis slot canyon.
The inset provides a close-up of the two objects, but the resolution is poor. To me, it is much more interesting to look at the picture to the right, that shows what these two objects actually looked like in the sky of Mars.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Fabulous!
I wonder if the Earth’s crescent is visible naked-eye?
Here’s what ChatGPT said:
“From Mars, Earth would appear as a crescent when it is between the Sun and Mars, similar to how we see the Moon’s phases. The largest angular size of Earth from Mars would be about 0.5 degrees, which is roughly the same as the Moon’s angular size as seen from Earth. However, the crescent shape would be most pronounced when Earth is in a waxing or waning phase, displaying a bright crescent against the darkness of space.”
I find this hard to believe.
So using some trig I come out with 0.01 deg which is much less than the 0.5 degrees for the Moon. So it would be right at the limit of the human eye.
pawn: The crescent in the picture is Phobos, not Earth. On Mars Earth will always appear like Venus, at dawn and sunset alternatively, and always as a crescent. In all cases however you will need a telescope or binocularos to see that crescent.
“… and always as a crescent.”
Not always. Like Venus, when it is near superior conjunction, i.e. about to go behind the Sun on the far side of its orbit, it will appear gibbous (like a not-quite-full Moon).
P.S. I think I got superior/inferior conjunction right here, but I never have been able to keep them straight. The other one is when [Venus/Earth] goes between the Sun and [Earth/Mars], when it is a crescent.
Call Me Ishmael: You are of course correct. I was a bit sloppy in my comment. I should have said “never full.”
I’ve heard/read the phrase “gibbous moon” but never bothered finding out what it meant. Ignorance is so easily cured, these days: ” a gibbous moon is one that is between half full and full.”