Mars is the 7th largest planet in our solar system and has been robotically explored more than any other planet outside of Earth since the 1960s.
Mariner 9 images in 1971 revealed the first direct evidence of water on the Red Planet. Still, only the recent ESA ExoMars and Mars Express missions have seen water ice for the first time near the equator of Mars, a part where ice was thought to be absent.
More information: Nature Geoscience
Dr. Adomas Valantinas and his team recently shared news of evidence of water frost seen near the equator of Mars.
Image credit: European Space Agency
Image credit: European Space Agency
Image credit: European Space Agency
The water frost was detected above the Tharsis Montes region, atop the Olympus Mons volcano, which rises about 26 miles above the surface of Mars and is three times higher than Mount Everest, the tallest not only on Mars but in the entire solar system. The remarkable discovery was made first by ESA’s ExoMars Trace Gas Orbiter (TGO) and then by ESA’s TGO and Mars Express.
The new data suggests that the frost is only available for a few hours after sunrise before it melts in the sunlight. Because Mars has a much thinner atmosphere than Earth, surface temperatures on the Red Planet can reach as low as 70 degrees Fahrenheit and as low as -225 degrees Fahrenheit.
“We thought it was unlikely that frost would form around the equator of Mars because the mix of sunlight and thin atmosphere keeps daytime temperatures relatively high both on the surface and at the top of the mountain – unlike what we see on Earth, where you would they could expect to see frosty peaks,” said Dr Adomas Valantinas, who made the discovery as a PhD student at the University of Bern in Switzerland and is now a postdoctoral researcher at Brown University in the US.
The research team believes that perhaps the way air circulates over the volcanic mountains creates a very specific microclimate that allows these thin frost particles to transform into very thin layers about the width of a human hair. Although the frost is so thin, it covers an incredibly huge area: the amount of frost represents about 150,000 tons of water, which is the equivalent of about 60 Olympic swimming pools.
“Its existence is exciting and suggests that there are exceptional processes at play that allow ice to form,” added Valantinas. “What we’re seeing may be a remnant of an ancient climate cycle on modern Mars where there was precipitation and possibly snow on these volcanoes in the past.”
The frost was recorded by the CaSSIS TGO instrument over the Tharsis Montes region, atop the Olympus Mons volcano
Image credit: European Space Agency
Image credit: European Space Agency
Image credit: NASA
Image credit: Sémhur
While this new discovery is the first time that water ice has been seen near the equator of Mars, many of us are probably wondering why it wasn’t seen earlier.
“There are several reasons: firstly, we need an orbit that allows us to observe the site in the early hours of the morning. While ESA’s two Mars orbiters – Mars Express and TGO – have such orbits and can observe at any time of day, many of the other agencies are synchronized instead with the Sun and can only observe in the afternoon,” Valantinas explained.
“Secondly, the deposition of ice is associated with a cooler Martian period, making the window for observing it even narrower. In short, we need to know where and when to look for the fleeting frost. We happened to be looking for it near the equator for some additional research, but we didn’t expect to see it on the tops of Martian volcanoes!” he added.
The icing was recorded by TGO’s CaSSIS instrument and then confirmed by revisiting the area with TGO’s Nadir and Occultation for Mars Discovery (NOMAD) spectrometer and Mars Express’ High Resolution Stereo Camera (HRSC).
“This discovery was made possible by successful collaboration between both ESA Mars orbiters and additional modelling. “Understanding which phenomena are the same or different on Earth and Mars really tests and improves our understanding of fundamental processes that take place not just on our home planet but elsewhere in space,” said Colin Wilson, who is ESA’s Project Scientist for ExoMars TGO and Mars Express.
“Finding water on the surface of Mars is always exciting, both for its scientific interest and its implications for human and robotic exploration,” he added. Wilson also pointed out that this new discovery is truly extraordinary because it shows that despite the low atmospheric pressure on Mars, which creates an unusual situation (the planet’s mountaintops are not usually colder than its plains), it appears that moist air can still condense in the frost. – an Earth-like phenomenon.
Another study investigated lava tubes on the surface of Mars that could provide astronauts with protection from extreme conditions in the future
Image credit: NASA
Image credit: NASA
Image credit: NASA
Another discovery by a different probe recently re-examined a series of mysterious holes about 10 feet in diameter located on the sides of volcanoes in the Tharsis region of Mars.
Scientists believe these holes are “skylights,” or places where the ground above the lava tubes has caved in, creating a hole in the surface. If these lava tubes are similar to the ones we have on Earth, then according to Brandon Johnson, who is a geophysicist at Purdue University, they could provide astronauts with protection from extreme conditions such as solar radiation, micrometeorites, extreme temperature fluctuations, winds, etc. and regolith dust storms.
“There’s more than one. [pits] on Mars that we’ve seen,” said Johnson, who studies impact craters across the solar system. “But they’re really interesting because they’re places where astronauts could go and be safe from radiation.”
However, a more detailed investigation is definitely needed to better understand the conditions.
“On Earth, these lava tubes can be big enough to walk in, but they can also be small, or the cavities can be discrete or discontinuous,” said Ross Beyer, who is a planetary scientist at the SETI Institute.
“So these pits that we’re seeing could be opening into larger caves, or they could just be isolated pits.” There’s no way to know what’s in them until we examine them in more detail,” he explained.
Johnson mentioned that the best way to get more information about the conditions inside the lava tubes would be to physically enter them with a rover: “There are missions designed to basically have the robot ride a line and fall into one of these skylights and was able to examine what was in them.”
Since, hypothetically, the mysterious holes could offer shelter from the harsh surface of the planet, they could also be the best place to look for possible alien life.
Image credit: European Space Agency
Image credit: NASA
Image credit: NASA
The Tharsis region covers nearly 25% of the Red Planet’s surface, and each new study provides scientists with vital information for future exploration and the search for possible signs of life.
At the moment, the only information is from orbital cameras in space, but hopefully soon it will be possible to explore Mars physically. And then, who knows what the most Earth-like planet will surprise us with next.
People on the Internet shared their excitement about the new discoveries on Mars