Why did the planet Mercury shrink – and perhaps still shrink today?

On the surface of the planet Mercury, researchers make a discovery that indicates that the smallest planet in the solar system is shrinking.

Milton Keynes – Mercury is one of the least explored planets in our universe Solar System. This is due to its proximity to sunWhich makes exploring the planet technically very difficult. It is also difficult to observe Mercury intensively from Earth because the Sun intervenes here as well.

The first spacecraft to visit Mercury was in 1974 NASA– Mariner 10 probe. It sent back images of the planet that showed, among other things, kilometer-high cliffs extending across the terrain for hundreds of kilometres. The MESSENGER spacecraft, which orbited Mercury from 2011 to 2015, showed more of these steep slopes. However, what may seem unspectacular is important information for geologists. Experts can see from these steep walls that the planet Mercury is shrinking.

Mercury is the smallest planet, and has been shrinking for billions of years

Mercury is already the smallest planet in the solar system, and has been shrinking in size for billions of years. Despite its proximity to the Sun, the planet’s interior cools and the stone and metal that make up the planet shrinks somewhat — the steep walls arise because the planet’s material has less area to cover and slides over each other. The assumption is that most of the cliffs are about three billion years old.

The extent to which Mercury is still shrinking today has not been clear for a long time, but a research team has now discovered evidence that the process may not be complete even today. In the study, In the specialized magazine Natural earth sciences published The team explains that not all cliffs on Mercury are three billion years old. “Our team found clear signs that many cliffs continued to move in recent geological times, even if they were formed billions of years ago,” David Rothery, co-author of the study, wrote on the portal. Conversation.

The steep slopes and trenches on Mercury show that the planet may still be shrinking

On some of the steep slopes they discovered grabens, a geological term that describes a piece of land that dips between two parallel faults. “This usually happens when the Earth’s crust expands,” Rothery explains. “The expansion might be sudden on Mercury, where the crust as a whole is compressed, but humans [ein Co-Autor der Studie, Anm. d. Red.] He realized that these trenches form when a piece of the Earth’s crust bends as it is pushed over the adjacent terrain. Likewise, if you try to bend a piece of toast, it can break.

The trenches are less than one kilometer wide and less than 100 meters deep. According to the research team, such relatively small structures must be much younger than the structure on which they are located, otherwise they would have been obscured for a long time by meteorite impacts. “Based on the speed of destruction caused by meteorite impacts, we calculated that most of the faults are less than 300 million years old,” Rothery writes. This suggests that the final movement must also be “modern.”

The BepiColombo space probe will orbit the planet Mercury starting in 2026

Starting in the beginning of 2026, the European-Japanese space probe “BepiColombo” is scheduled to orbit the planet Mercury and then collect more information about the trenches on the planet. However, the spacecraft will not land, so it will not be possible to collect seismic data from the planet. However, the probe will likely allow small trenches to be examined in more detail and more conclusions drawn from new data. (unpaid bill)