For the first time, scientists have noticed that “megaripples” on Mars – huge waves of sand visible on the surface of Mars – are moving structures, not ancient relics trapped in a place far from the Red Planet’s distant past.
Megaripples, which also occur in deserts on Earth, are usually larger than smaller waves of sand and are made up of larger, finer grains of sand sitting at the top of their lobes, resting on the smaller grains buried at the bottom.
The grains of the most indifferent grains — along with the very thin and weak winds of the light atmosphere of Mars today — had scientists believed that these sedimentary structures must be static and immovable formations. Not so, new research suggests.
A study by planetary scientist Simone Silvestro of the INAF Capodimonte Astronomical Observatory in Italy reveals that Mars megaripal is an ever-flowing phenomenon ̵1; although you have to watch very, very carefully to catch them in action.
Comparing images taken with a HiRISE camera (high-resolution imaging experiment) over NASA’s MARS Reconnaissance Orbiter over several years, Silvestro’s team discovered that Martin’s megaripples were really moving, only very slow motion.
Since 2007 Until 2016 The megaripples of two Martian sites, the Nili Fossae and McLaughlin craters, tilted at an average speed of as much as 12 centimeters (4.7 inches) per year, with a maximum recorded speed of 19 centimeters (7.5 inches) per year.
At such a slow rate of displacement, it is not surprising that these changing sands were considered static – and previous comparisons examining the formation of a shorter, only two or three years of Mars, failed to detect a subtle level of migration. Now, thankfully, we have more probe data that we can rely on to take a closer look at what’s going on.
“We had the opportunity to see these megaripples moving because we now have more than 10 years of observations,” Silvestro explained to Inside Science.
However, it is not just the probe images that have been expanded. So our understanding of what is possible in the atmosphere of Mars, and in the past, researchers did not think that the winds of Mars in a thin atmosphere would be powerful enough to move megaripples – which are so large that they were up to 35 meters (115 feet) away. (although the average is about 5 meters or 16 feet).
It seems that the wind of Mars can move large propellers as long as it has some help. The researchers suggest that the larger sand dunes at the Nili Fossae and McLaughlin crater sites studied could help move megaripples, while the smaller-grained dunes provide a large flow of sand that can help displace the fine grains sitting above. megaripple crests.
In addition to this level of “shock creep” from neighboring island dunes, other Mars “megaripples” may not be able to move as fast or as fast as a fast squad.
While these megaripals may be slow, the fact that we can move them altogether not only means a significant increase in our knowledge of atmospheric conditions on Mars – it is also just some of the most impressive scientific work.
As told by planetary scientist Ralph Lorenz of Johns Hopkins University, who was not involved in the research Science: “Now we can measure processes on the surface of another planet that are only a few times faster than growing our hair.”
The conclusions are presented Journal of Geophysical Surveys: Planet.