Latest findings about the planet Mercury suggests that its magnetic field is nearly four billion years old. Scientists used data gathered by the Messenger spacecraft to come to this unusual conclusion.
For those who don’t know: Messenger stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging. The spacecraft was launched for collecting data from Mercury more than ten years back, to be more precise, in August 2004.
It took another seven years to reach the planet. During the next four years, the observatory studied the planet to gather essential facts and figures about it. Here, it must be mentioned that the Messenger’s planned mission life was just of 12 months; this means, it took three more years to complete its mission on Mercury.
During this study, it was found that like our planet, Mercury also possesses a magnetic field. However, its magnetic field is much weaker compared to the one that surrounds the planet Earth. According to astronomers, this particular electromagnetic feature stems from movements of liquid iron within Mercury’s core; this is probably because something similar happens with our home planet.
Mercury was created around the same time when the sun and the remaining entities of our solar system were created, which makes it a planet of nearly 4.4 billion years. Data offered by Messenger suggests that the planet’s magnetic field was first formed around 3.7 to 3.9 billion years back.
This feature of Messenger was detected by a magnetometer in the long-standing observatory. The magnetometer succeeded in identifying this feature when the spacecraft started to get closer to Mercury’s surface at the end of the last calendar year and the beginning of this year. This is because the magnetic power of the rocks on Mercury’s crust was not strong enough to be recorded from a higher orbit.
Catherine Johnson of the University of British Columbia and one of the authors of the study informed that the history of a planet’s magnetic field is always recorded by magnetized rocks. She added that it was already known that 3.7 to 3.9 billion years back, Mercury was tectonically and volcanically active and with these new findings it can be said that around the same time the planet also got its magnetic field. The entire study can be read in the journal Science.
For those who are wondering why these findings by the researchers are so special: neither Mars nor Venus possesses any magnetic field around them. Past researches, however, suggest that the Red Planet used to have a magnetic field around it more than three billion years back.