Spectacular 'Sideways Glance' of Mt. Sharp in Gale Crater

By Nancy Atkinson - August 17, 2012 at 8:11 PM UTC | Planetary Science
mt-sharp-oblique.jpg

Yep, you really want to

click on this link

to see the full color version of this great oblique view of Mt. Sharp (a.k.a. Aeolis Mons) in Gale Crater, taken by the HiRISE camera on the Mars Reconnaissance Orbiter. Or you can

click here

to see the full "raw" strip from the spacecraft.

"The viewing angle is 45 degrees, like looking out an airplane window," wrote HiRISE Principal Investigator Alfred McEwen on the HiRISE website. McEwen noted that this color version doesn't show the Curiosity rover or the hardware left over from the landing on Mars, but it does provide a great view of Gale Crater's central mound.

So how "true" is the color in this image?

"It may be close, but not true," Christian Schaller from the HiRISE team told Universe Today. Schaller pointed out

the description

(pdf) of color in HiRISE images from the HiRISE team:

It isn't natural color, as seen by normal human eyes, because the IR, RED, and BG channels are displayed in red, green, and blue colors. For the Extras products, each color band is individually stretched to maximize contrast, so the colors are enhanced differently for each image based on the color and brightness of each scene. Scenes with dark shadows and bright sunlit slopes or with both bright and dark materials are stretched less, so the colors are less enhanced than is the case over bland scenes.

Jim Bell, the lead scientist for the Pancam color imaging system on the Mars Exploration Rovers, said he likes to use the term "approximate true color" because the MER panoramic camera images are estimates of what humans would see if they were on Mars. Other colleagues, Bell said, use "natural color."

"We actually try to avoid the term 'true color' because nobody really knows precisely what the 'truth' is on Mars," Bell told Universe Today in 2007 for an

article about the art of extraterrestrial photography

. In fact, Bell pointed out, on Mars, as well as Earth, color changes all the time: whether it's cloudy or clear, the Sun is high or low, or if there are variations in how much dust is in the atmosphere. "Colors change from moment to moment. It's a dynamic thing. We try not to draw the line that hard by saying 'this is the truth!'"

For more great shots from HiRISE,

check out their website.

Source:

HiRISE

Nancy Atkinson

Nancy Atkinson

Nancy Atkinson is a space journalist and author with a passion for telling the stories of people involved in space exploration and astronomy. She is currently retired from daily writing, but worked at Universe Today for 20 years as a writer and editor. She also contributed articles to The Planetary Society, Ad Astra (National Space Society), New Scientist and many other online outlets.

Her 2019 book, "Eight Years to the Moon: The History of the Apollo Missions,” shares the untold stories of engineers and scientists who worked behind the scenes to make the Apollo program so successful, despite the daunting odds against it. Her first book “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” (2016) tells the stories of 37 scientists and engineers that work on several current NASA robotic missions to explore the solar system and beyond.

Nancy is also a NASA/JPL Solar System Ambassador, and through this program, she has the opportunity to share her passion of space and astronomy with children and adults through presentations and programs. Nancy's personal website is nancyatkinson.com