Data from the recently crash-landed MESSENGER space probe suggests that Mercury’s magnetic field is close to four billion years old.
The probe had gone on a four-year mission to Mercury, orbiting the planet and gathering data that has since helped scientists understand more about the planet in our solar system closest to the Sun. In 2008 MESSENGER had flew by Mercury for the first time, about four years after it left Earth, and had been orbiting since 2011 before crashing into the planet due to a lack of fuel. Despite the fact that MESSENGER is no more, the new data published Thursday on the journal Science Express could prove interesting in the quest to learn of Mercury’s origins.
“The mission was originally planned to last one year; no one expected it to go for four,” said University of British Columbia planetary scientist Catherine Johnson, who leads a study analyzing this new data from MESSENGER. “The science from these recent observations is really interesting and what we’ve learned about the magnetic field is just the first part of it.”
Prior to the new findings, it was believed that Mercury’s magnetic field is similar to that of Earth, albeit much weaker. It’s also known that the planet is the only other one aside from Earth in the inner solar system to have such a magnetic field. But the age of this field had been a great unknown until the release of MESSENGER’s findings. These suggest that Mercury’s magnetic field is at least 3.7 to 3.9 billion years old, having formed less than a billion years after the planet formed 4.5 billion years ago.
“If we didn’t have these recent observations, we would never have known how Mercury’s magnetic field evolved over time,” Johnson added in a UBC press release. “It’s just been waiting to tell us its story.”