The icy moon Enceladus is covered in a deep covering of snow.

 

The icy moon Enceladus is covered in a deep covering of snow

The fluffy stuff seems to indicate that the famed plume on the moon was once more active than it is now.

Enceladus, a moon of Saturn, is completely covered in a thick blanket of snow. According to the findings of recent study, the fluffy substance may reach a depth of 700 meters in certain locations.

Emily Martin, a planetary scientist, was quoted as saying, "It's like Buffalo, but worse," in reference to the well-known snowy city in the state of New York. According to the findings that Martin and his colleagues published in the journal Icarus on March 1st, the snow depth provides evidence that Enceladus' impressive plume may have been more active in the distant past.

Since the Cassini probe discovered them in 2005 (SN: 12/16/22) planetary scientists have been mesmerized by the geysers that can be found on Enceladus. These geysers are composed of water vapor as well as other components. It is likely that the spray originates from a salty ocean hidden under an ice shell.

(SN: 5/2/06) Some of the water contributes to the formation of one of Saturn's rings. However, the majority of it, according to Martin, falls back down onto the surface of the moon as snow. Finding out more about the characteristics of that snow, such as its depth, as well as how dense and compact it is, might help shed light on the past of Enceladus and pave the way for future exploration of this moon.

"If you're going to land a robot there, you need to understand what it's going to be landing into," says Martin, of the National Air and Space Museum in Washington, D.C. "If you're going to land a robot there, you need to understand what it's going to be landing into."

Martin and his colleagues turned their attention to Earth, more especially Iceland, in order to gauge the depth of the snow on Enceladus. Pit chains are lines of pockmarks in the ground that occur when loose material such as boulders, ice, or snow pours into a fissure below the surface of the island nation (SN: 10/23/18). These pit chains are one of the geological characteristics that can be seen on the island. The whole of the solar system, including Enceladus, has characteristics that are quite similar to one another.

Previous research brought to light the possibility of determining the depth of the holes by using geometry and the angle at which sunlight strikes the surface. Following this measurement, the depth of the substance that the pits are situated in may be determined. A short period of time spent doing research in Iceland in 2017 and 2018 was enough to persuade Martin and her colleagues that the same method would be successful on Enceladus.

Martin and his colleagues discovered, with the use of photos obtained from Cassini, that the depth of the snow changes over the surface of Enceladus. At its thickest point, it is 700 meters deep, although in most locations it is just a few hundred meters deep.

However, according to Martin, it is difficult to comprehend how all of that snow got there. If the spray from the plume had always been the same as it is now, it would take 4.5 billion years, which is the whole life of the solar system, to lay that much snow on the surface. Even so, the snow would have to be of a very light and airy consistency.

According to Martin, it is very improbable that the plume became active the instant the moon was born and remained unchanged throughout time. And even if it had, subsequent layers of snow would have compacted the previous ones, resulting in the layer as a whole being considerably less deep than it is right now because of the compacting effect.

Martin adds that it leads him to believe that we do not have 4.5 billion years to complete this task. Instead, it's possible that the plume used to be quite a little more active in the past. "We need to do it in a much shorter amount of time. It might be helpful if you turned up the volume on the plume.

According to Shannon MacKenzie, a planetary scientist who works at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, the method was ingenious. There is no way to determine how deep below the surface the snow extends since there are no rovers or astronauts on the ground to do so. Instead, the writers are using geology in a really astute manner in order to serve as their rovers and shovels.

MacKenzie was not engaged in the new work; however, she did lead a mission concept study for an orbiter and lander that may one day explore the planet Enceladus. When doing the investigation, one of the most important concerns that needed to be answered was the location of a safe landing zone for a lander. She thinks that the most important question throughout those conversations was, "What do we anticipate the surface to be?" The new article could be able to assist in "identifying the regions that are too fluffy to land in."