The infamous Happy Face crater on Mars near the south pole is smiling even brighter over the last decade. The grinning visage was first discovered in 2011 by NASA's Mars Reconnaissance Orbiter using its powerful High-Resolution Imaging Science Experiment camera (HiRISE).

According to Universe Today, a new image captured in 2020 has proven that it has changed over the past ten years due to thermal erosion. As the carbon dioxide evaporates and exposes more soil, the 'nose' of the Happy Face crater has also grown into one large depression from two small dots, while the 'smile' has also grown significantly.

Thermal Erosion Reveals More of the Martian Soil

Planetary scientist Ross Beyer of the Sagan Center at the SETI Institute said that almost a decade of thermal erosion had made the Happy Face crater smile larger. Also, it looked like it has gotten a nose job with the two depressions merging to form only one depression.

He added that measuring these changes on the Happy Face crater through the Martian year could help them understand the annual deposition and removal of polar frost. Monitoring these regions for long periods can give insight into the longer-term climate trends on Mars.

Thermal erosion has revealed more of the surface of the crater, which makes the smile appear larger. Also, some blobby features have changed shape still because of thermal erosion from the Sun, which causes sublimation, or the phenomenon when a solid turns into a gas without passing the liquid state, which causes more erosion.

According to MailOnline, the evaporated frost may have settled anywhere on the planet but carbon dioxide ice was created near the poles, which only shift throughout the year as the climate on the planet changes. The elevations that the different ice densities on the surface represent the distinct features seen above.

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Seeing Inanimate Objects on Mars

The Happy Face crater is not the only inanimate object that is seen on Mars. Last year in December, astronomers from the European Space Agency's Mars Express satellite have captured a photo of what looks like an angel that has wings and a halo near the south pole of Mars.

According to a previous report of Science Times, seeing human faces of familiar images on objects or landscapes is called pareidolia. For instance, this angel landscape on Mars is visible because of the nearby dune fields' pattern and composition. Additionally, the hand of the angel that looks like it is reaching to the left is a large sublimation pit.

The angel pattern was spotted between Ultimata Lingula and Ultima Chasma.

But over the years, astronomers have also spotted other images, like a rabbit, dragon, and a bat signal. In 2020, the Mars Reconnaissance Orbiter uncovered an impact crater that looked like Ed Asner, according to CNet's report.

The first that astronomers spotted a face on the Red Planet was in 1976, taken by Viking 1 Orbiter. Analysis has shown that the land formation is a chance alignment of mineral dunes.


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Check out more news and information on Mars in Science Times.