This article, Tempting blue pools in vivid Mars photo aren't what they seem, originally appeared on CNET.com.

If they're not lakes, then just what are they? ESA/DLR/FU Berlin

Thus far, the search for water on Mars hasn't led to the discovery of any major sources of the stuff. Sure, we know that the planet probably used to have vast lakes and that mountains might show streaks of water down their sides, but so far, no South Pacific-like beaches. And, even though a recent picture from the European Space Agency shows what look like large blue pools on the Red Planet's surface, it turns out that -- alas -- the pools are just optical illusions.

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"At first glance, this image seems to show something amazing in this crater, and in one of its neighbors to the right," the ESA explains, but really the color is just "an optical illusion caused by the image processing."

What those blue patches really are, according to the agency, is "dark sediments that have built up over time."

Ah, well, so much for that beach vacation on Mars.

The image was snapped by the ESA's Mars Express orbiter, which has been zipping around and spying on the Red Planet since December 2003. The picture was taken by one of the orbiter's high-tech cameras on the craft's 1,3728th orbit around the planet, in November 2014, and was featured as an image on the agency's website on Monday.

In addition to providing a big, "Fooled ya, no water here!" moment, the image shows the impact of high winds on Mars. The winds, which can reach speeds of up to 62 miles per hour (100 kph), both distribute the sediment and exert a scrubbing effect on the many impact craters that pock the planet's surface. The large 70-kilometer-wide crater on the left still has steep sides that have yet to be ground down by the winds, but other craters in the image are more eroded.

So even if those blue blotches had been lakes, with winds like that, "beach days" wouldn't come around very often. Oh, and even if they did, you wouldn't be able to breathe while lying out on your beach blanket. Come to think of it, a trip to Mars doesn't sound that appealing after all.

Mars Express: 10 years of capturing the Red Planet in full color (pictures)

Mars Express, the first planetary explorer for the European Space Agency, is celebrating 10 years of taking images of the Red Planet. Using data obtained from the High-Resolution Stereo Camera (HRSC) onboard, the spacecraft has returned hundreds of images since the mission began.

The HRSC has been imaging the planet in color and 3D with a resolution of about 10 meters. Selected areas have been imaged in even greater detail, at a 2-meter resolution. One of the camera's greatest strengths is the pointing accuracy achieved by combining images at the two different resolutions, along with the perspective view of the 3D imaging created with the MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) which has revealed the topography of Mars in full color.

"As the 2-metre resolution image is nested in a 10-metre resolution swath, we will know precisely where we are looking. The 2-metre resolution channel will allow us to pick out great detail on the surface," says Gerhard Neukum, HRSC principal investigator from Freie Universität Berlin, Germany.

Here, Mars Express offers a close-up view of the mesa inside Hebes Chasma. Material has slumped down onto the floor of the valley below, and along the side of the mound fine horizontal layering is seen, likely a mix of wind-blown dust and ancient lake sediments, along with remnants of more ancient plateaus.

The region seen here around Magellan Crater on the southern highlands of Mars stretches 190 by 112 kilometers, and covers an area of about 21,280 square kilometers, about the size of Slovenia.

This long, unnamed depression is located just south of the much larger Huygens crater. About 78 km in length, it opens from just under 10 km wide at one end to 25 km wide at the other, and reaches a depth of 2 km. ESA scientists say they believe the surrounding blanketed material looks as if it may have been ejected from an impact.

In the distant past, the ESA says, large volumes of water must have rushed through the Ares Vallis. Streamlined islands have been eroded on the valley floor, indicating the direction taken by the water in this image captured on May 11, 2011.

Phlegra Montes, seen here, is a range of gently curving mountains and ridges on Mars extending from the Elysium volcanic province to the northern lowlands in this perspective view.

This is the western half of the 138-kilometer-wide Hooke Crater, in the region of Argyre, with wind-formed dunes and ice-covered plains coated with a thin dusting of frozen carbon dioxide.

This natural-color view of Nereidum Montes shows concentric crater fill in many of the craters in the lower part of the image, which the ESA says it believes is the result of glacial movement.

This natural-color view shows two craters, each around 50 kilometers in diameter in this image from the Thaumasia Planum region of Mars just south of Vallis Marineris.

With jagged fractures and fault lines, and channels likely caused by lava flows or water, this image shows part of the ridge and valley system of Sulci Gordii.

This mosaic, which features the spectacular Kasei Valles, is made up of 67 images taken with the High-Resolution Stereo Camera on ESA's Mars Express.

In the ancient cratered southern highlands of Mars, the ESA says, traces of a wet past are seen in the form of channels visible in the lower center of the image, fluidized debris around craters at the bottom right, and blocks of eroded sediments seen in the top left.

The image was taken by the High-Resolution Stereo Camera on Mars Express on January 15, 2013, with a ground resolution of approximately 22 meters per pixel.

The carved channel along the valley floor at Reull Vallis is believed to have been formed by flowing water or ice, which eons ago had cut through the highland terrain to form smooth plains, much like the glacial valleys of Earth.