New research shows how there are no volcanic activity or water streams on Mercury. Nor explosive, or effusive movements have occurred on the planet lately. Scientists estimate that the last seismic activity dates back 3. 5 billion years ago.
Mercury is the smallest planet in our solar system. Although Mars and Earth are also small planets, this celestial body is even smallest. It is also placed closest to the sun.
Scientists at the North Carolina State University investigate the seismic activity of the smallest planet. They used data collected by a NASA spacecraft, which had been orbiting Mercury for four years, and it’s mission reached the end.
Specialists explain the two type of seismic activity which they could have expected on Mercury. One of them is explosive: we encounter this phenomenon on Earth as well. It is what happens when a volcano erupts: it throws lava, hot rocks, air and gas into the atmosphere. Effusive phenomena also happen on Earth, and stand for the process of lava slowly going downhill on the versants of the volcano. Volcanoes can’t be both effusive and explosive. Scientists found signs of none of that during their latest study.
Researcher Paul Byrne (North Carolina State) takes about the results of the research:
“These new results validate 40-year-old predictions about global cooling and contraction shutting off volcanism. Now that we can account for observations of the volcanic and tectonic properties of Mercury, we have a consistent story for its geological formation and evolution, as well as new insight into what happens when planetary bodies cool and contract.”
Geologist Paul Byrne also explains the differences between this planet and other ones which preserve volcanism, such as Earth:
“There is a huge geological difference between Mercury and Earth, Mars or Venus. Mercury has a much smaller mantle, where radioactive decay produces heat, than those other planets, and so it lost its heat much earlier. As a result, Mercury began to contract, and the crust essentially sealed off any conduits by which magma could reach the surface.”
The study showed researchers that previous predictions on the volcanism of the smallest planet in our solar system turned out to be true. The phenomena ceased on the planet 3,5 billion years ago, which makes Mercury a quiet planet. If it weren’t for its movement round the Sun, this celestial body could have been labeled as a “still” planet.
Image source: Wikipedia