Curiosity Sees Blue Sunset on Red Planet

NASA's Curiosity Mars rover recorded this view of the sun setting at the close of the mission's 956th Martian day, or sol (April 15, 2015), from the rover's location in Gale Crater. Credit: NASA/JPL-Caltech/MSSS/Texas A&M Univ.

NASA’s Curiosity Mars rover recorded this view of the sun setting at the close of the mission’s 956th Martian day, or sol (April 15, 2015), from the rover’s location in Gale Crater. Credit: NASA/JPL-Caltech/MSSS/Texas A&M Univ.
See dramatic blue Martian sunset animation and matching daylight view below!

After nearly three years of laboring on the Red Planet, NASA’s Curiosity Mars Science Laboratory (MSL) rover has finally captured her first color sunset on Mars—in living blue color!

And it’s a whopper. It looks for all the world not like an alien world, but rather like a majestic sunset back here on Earth, from nearly anywhere where there are overlooks at hills and mountains on the Home Planet—except it’s blue hued rather than red.

The breathtaking color images were captured by Curiosity’s Mast mounted color camera in April, but only just recently transmitted back across the vast gulf of hundreds of millions of miles (kilometers) of interplanetary space.

“The sun dips to a Martian horizon in a blue-tinged sky in images sent home to Earth this week,” NASA officials said in a statement.

The one-ton robot’s Mast Camera (Mastcam) recorded the dramatic blue sunset during an evening of skywatching on April 15, 2015, or Sol 956, of her work investigating the Red Planet.

A still image is shown above. A four-image sequence combined into a GIF animation is shown below.

The quartet of sunset images for the animation were taken over a span of just 6 minutes, 51 seconds and are the rover’s first color images of a sunset from Curiosity.

The Mastcam images were taken by the robot’s wider angle left eye 34 mm color camera, built by Malin Space Science Systems, based in San Diego, Calif.

“Mastcam sees color very similarly to what human eyes see, although it is actually a little less sensitive to blue than people are,” according to the science team. They have been color calibrated and white-balanced to remove camera artifacts.

NASA's Curiosity Mars rover recorded this sequence of views of the sun setting at the close of the mission's 956th Martian day, or sol (April 15, 2015), from the rover's location in Gale Crater. Credits: NASA/JPL-Caltech/MSSS/Texas A&M Univ.

NASA’s Curiosity Mars rover recorded this sequence of views of the Sun setting at the close of the mission’s 956th Martian day, or sol (April 15, 2015), from the rover’s location in Gale Crater.
Credits: NASA/JPL-Caltech/MSSS/Texas A&M Univ.

Currently, Curiosity is investigating the very picturesque foothills of Mount Sharp, which towers 3.4 miles (5.5 kilometers) into the Martian sky and dominates the center of the Gale Crater landing site, where she safely touched down on Aug. 5, 2012.

Mount Sharp is comprised of sedimentary rock layers that record the history of ancient Martian environments and is the primary destination of the mission.

The rover is examining how environmental conditions changed over billions of years, and how their potential to support microbial life changed in Mars’ early history.

For a daylight view of this area showing Mount Sharp, see our photo mosaic herein created by the image processing team of Marco Di Lorenzo and Ken Kremer.

The sundown images were taken in between dust storms, although some dust remained suspended high in the very thin Martian atmosphere, which is less than 1 percent as thick as Earth’s.

What is the source of the colors?

“The colors come from the fact that the very fine dust is the right size so that blue light penetrates the atmosphere slightly more efficiently,” said Mark Lemmon of Texas A&M University, College Station, the Curiosity science-team member who planned the observations.

“When the blue light scatters off the dust, it stays closer to the direction of the sun than light of other colors does. The rest of the sky is yellow to orange, as yellow and red light scatter all over the sky instead of being absorbed or staying close to the sun.”

Here is the matching daylight view of the same Martian landscape:

NASA's Curiosity Mars rover recorded this matching daylight view from the same Martian landscape on the same sol as the sunset view taken at the close of the mission's 956th Martian day, or sol (April 15, 2015), from the rover's location in Gale Crater. Credit: NASA/JPL/MSSS/Ken Kremer/kenkremer.com/Marco Di Lorenzo

NASA’s Curiosity Mars rover recorded this matching daylight view from the same Martian landscape on the same sol as the sunset view taken at the close of the mission’s 956th Martian day, or sol (April 15, 2015), from the rover’s location in Gale Crater. Credit: NASA/JPL/MSSS/Ken Kremer/Marco Di Lorenzo

We all know from living on Earth that colors are much more dramatic during sunsets. The same is true on Mars.

“Martian sunsets make the blue near the sun’s part of the sky much more prominent, while normal daylight makes the rusty color of the dust more prominent.”

“Dust in the Martian atmosphere has fine particles that permit blue light to penetrate the atmosphere more efficiently than longer-wavelength colors. That causes the blue colors in the mixed light coming from the sun to stay closer to sun’s part of the sky, compared to the wider scattering of yellow and red colors. The effect is most pronounced near sunset, when light from the sun passes through a longer path in the atmosphere than it does at mid-day.”

NASA's Curiosity Mars rover rolling across Mars at the foothills of Mount Sharp, seen in the background, in this mosaic of images taken on April 11, 2015 (Sol 952).  Navcam camera raw images stitched and colorized. Credit:  NASA/JPL-Caltech/ Marco Di Lorenzo/Ken Kremer/kenkremer.com

NASA’s Curiosity Mars rover rolling across Mars at the foothills of Mount Sharp, seen in the background, in this mosaic of images taken on April 11, 2015 (Sol 952). Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/ Marco Di Lorenzo/Ken Kremer/kenkremer.com

Besides providing beautifully pleasant images, sunset observations are also useful scientifically because researchers say they can use the images to “assess the vertical distribution of dust in the atmosphere.”

Coincidentally, at virtually the same time, as she was snapping these gorgeous sunset imagery, Curiosity had just passed the 10 kilometers (6.214 miles) mark on Sol 957 (April 16) for total driving since her August 2012 touchdown.

Curiosity was making tracks and science observations while on the move and heading southward seeking science targets at the mountain foothills.

“We’ve not only been making tracks, but also making important observations to characterize rocks we’re passing, and some farther to the south at selected viewpoints,” said John Grant of the National Air and Space Museum, Washington, in a statement. Grant is a Curiosity science team member who has recently served as the team’s long-term planner.

For the past six months, Curiosity has been investigating an enticing area called the “Pahrump Hills” outcrop at the base of Mount Sharp, including most recently at a beautiful patch of water-altered mineral veins she discovered at the “Garden City” outcrop in late-March, on her epic trek now around the foothills of Mount Sharp, as reported here.

The six-wheeled rover is now investigating a hillside area and a valley at the mountain base called Mount Shields, to see how it all fits in to the context of Gale Crater.

She has taken some 239,900 images over 985 Sols of exploration.

NASA's Curiosity Mars rover rolling across Mars at the foothills of Mount Sharp, seen in the background, in this mosaic of images taken on April 11, 2015 (Sol 952).  Navcam camera raw images stitched and colorized. Credit:  NASA/JPL-Caltech/ Marco Di Lorenzo/Ken Kremer/kenkremer.com

NASA’s Curiosity Mars rover rolling across Mars at the foothills of Mount Sharp, seen in the background, in this mosaic of images taken on April 11, 2015 (Sol 952). Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/ Marco Di Lorenzo/Ken Kremer/kenkremer.com

Stay tuned here for continuing updates from Mars and throughout our Solar System!

Ken Kremer

 

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8 comments to Curiosity Sees Blue Sunset on Red Planet

  • Byron Hood

    Awesome work by Mark Lemmon and his team of Aggies, as well as the fine folks at JPL! My wife Karen and I attended the MSL launch in 2011 from CCAFS, and were present at JPL when CURIOSITY landed on Mars in 2012.

  • Jeff Wright

    Great stuff

  • Karol

    To think that of 100,000 generations that came before us in over four million years of human evolution, we are the extremely fortunate ones to see these sights. What awaits us . . . ?

  • Gary Church

    Yes, it is interesting and there is no denying the novelty. But when the novelty wears off it is an airless irradiated lifeless desert. Too much gravity to land on easily and not enough to keep a human being healthy. Too far away for any solar energy related industry. Anyone born their would dream of living on Earth but would be debilitated from birth and have to visit in a wheelchair.

    Radiation is the big problem for surface exploration and astronauts in the future will not want to waste any of their their lifetime exposure budget here. Anyone wanting to get outside a shielded spaceship and explore will have much better luck going to Navy dive school. Scuba divers and mini-sub pilots are the most likely future alien world explorers. Extended human exploration will be practical in the subsurface oceans of the gas giant moons but due to radiation there is only one place where surface exploration will a viable long term option- Titan.

    For those who dream of wandering the surface of an alien world there is only one place to do it without suffering harmful radiation exposure yet Titan is rarely mentioned in this context. In fact, all that is required is a heated coverall and oxygen mask. The over 100 pounds of a constricting pressurized space suit would not be needed. A set of artificial wings strapped to your arms would come in handy though as the gravity is low enough that human powered flight is easily accomplished. Mars has long been portrayed as being the place for surface explorers but the radiation actually makes the opposite true- and true of everywhere except Earth and Titan.

    Titan is the place people should dream of exploring- NOT Mars.

  • Gary Church

    The third place explorers might quench there wanderlust is in caves- the giant riles theorized to exist on the Moon might rival the 50 mile long record cave systems on Earth and due to the lower gravity be much larger. And other moons may have some similar “dry” systems. Unfortunately these underground sports arena size riles on our Moon are not going to be found near the most likely ice deposits at the poles according to one expert I have asked. Transporting the water and volatiles from the poles to any volcanically formed natural underground sanctuaries at higher latitudes is perhaps not that big a problem using robot trucks.

  • It is interesting how some dismiss Mars as a target for human exploration in part because its low surface gravity (~38% of the Earth) is allegedly insufficient to keep humans healthy yet embrace a human presence on Titan which, in addition to being much more difficult to reach than Mars, has only ~14% of Earth’s surface gravity (i.e. the surface gravity of Titan is only 36% of that of Mars). In terms of surface gravity, Titan is a less healthy place for humans than Mars! Of course the entire vision of exploiting resources beyond Earth orbit (bypassing Mars because of its association with the evil New Space Conspiracy (TM)!) is predicated on establishing a presence on the Moon which has a surface gravity less than half as great as Mars which allegedly has in sufficient surface gravity to keep humans healthy.

  • Gary Church

    I will try again.
    There is a difference between exploration and colonization.

    • You made no such explicit distinction in your comment above nor is it clear that a distinction would logically make any difference in your claims.