Mercury’s magnetic field is 4 billion years old, according to what the MESSENGER spacecraft learned as it evaluated the surface at close range.
Mercury’s magnetic field as been at the center of a lot of debate over the course of the last several years. Scientists have continued to do a lot of research on the magnetic fields of various planets because it’s one of the building blocks for these planets. It’s what holds their atmosphere together, it’s what keeps everything in line, and what ultimately drives the planets to spin and rotate the way they do.
Initially, the mission was only going to last a year. However, it wound up lasting 4 years, and in the process, some of the most impressive data that has ever been received regarding Mercury was uncovered through it. The research team found that the magnetic field of Mercury formed between 3.7 and 3.9 billion years ago. Catherine Johnson, who was a part of the team, pointed out, “The mission was originally planned to last one year; no one expected it to go for four. The science from these recent observations is interesting and what we’ve learned about the magnetic field is just the first part of it.”
She went on to point out, “Magnetized rocks record the history of the magnetic field of a planet, a key ingredient in understanding its evolution. We already know that around 3.7 to 3.9 billion years ago Mercury was volcanically and tectonically active. We now know that it had a magnetic field at around that time.”
Johnson closed by pointing out, “If we didn’t have these recent observations, we would never have known how Mercury’s magnetic field evolved over time. It’s just been waiting to tell us its story.” MESSENGER was active between 2011 and 2015, and it was one of the most informative missions that had taken place in the last decade. The information about Mercury that was obtained through this study have brought to light something that otherwise never would have been understood.
Before this, scientists only knew that Mercury had a magnetic field. They didn’t know how strong that field was, and the best indicator they had previously was that the magnetic field was very similar to Earth. However, that magnetic field was significantly weaker than what was had here on Earth at any point.
Ultimately, this is another layer of information that scientists will be able to take moving forward and analyze along with the information that researchers can in the future. MESSENGER’s work ended last week when the spacecraft crashed into the planet. This lays the groundwork for future work and studies on the planet, and will hopefully give scientists a better impression of what Mercury is compared to Earth beneath the surface.