NASA MESSENGER tells molten core is behind Mercury’s magnetic field

NASA’s MESSENGER spacecraft has done something that scientists and researchers have been trying to do for years. It managed to get close enough to Mercury, throughout the course of its mission, to detect and determine the details of Mercury’s magnetic field. One of the big mysteries that surrounded Mercury and its magnetic field was the fact that it shared a lot of similarities with Earth.

That’s to say that, while it was not the same strength as Earth, it had similar characteristics that made it similar in function and scope. That being said though, the magnetic field, as it turns out, is just one that operates on a smaller scale than Earth’s.

The research that MESSENGER was able to accomplish before the spacecraft crashed gave unique perspective in terms of telling scientists how the magnetic field on Mercury evolved throughout history. Catherine Johnson, the lead author of the study, pointed out that, “This means Mercury’s core has to be at least partially liquid.”


She went on to point out, “This was a surprise at first because Mercury is very small, so you would expect it to cool quickly after it formed and be completely solid. Scientists later realized if there was a little bit of nonmetallic stuff in Mercury’s core, that’d lower its freezing point and make it hard to be completely solid.”

The mission began in 2011 and ended when the MESSENGER spacecraft crashed at the end of April. Some of the important findings that came at the hands of MESSENGER included, understanding that magnetized rocks could give scientists a peak into the world of any planets magnetic history.

Meaning, due to the magnetized rocks – scientists would then be able to make determinations regarding the history and how that magnetic field evolved throughout the years. It also yielded an understanding that the crust of Mercury has a very low-density count of iron, which is important in terms of understanding that this is something that happened over an extended period of time.

Mercury now is better understood than it ever was before, and that is largely due to MESSENGER, and the work of the scientists that worked on this study. While MESSENGER might be a part of scientific history, the things that were learned from this mission will be studied for years and years to come. This gives scientists moving forward a wealth of knowledge, for executing further studies on Mercury as it pertains to the makeup of the planet.