Mercury has a weak magnetic field exactly like Earth's, something scientists were shocked to find due to its small size.
For billions of years, Mercury may have once had a magnetic field that rivaled that of Earth’s, according to new research.
NASA’s recently crashed MESSENGER space probe, which was the first probe to orbit Mercury in 2011, sent data to NASA that shed more light on how the planet evolved over time, according to a Space.com report.
It’s the smallest planet and the closest one to the sun, and scientists didn’t know much about it until MESSENGER took a closer look a few years back — the only other visits from spacecraft was NASA’s Mariner 10 probe 40 years ago, and that was just a flyby. MESSENGER’s mission ended April 30 when it slammed into the surface of Mercury.
Mariner 10 was the first to find that Mercury had a magnetic field that was similar to the one on Earth, although 100 times weaker. Just like Earth, Mercury gets its magnetic field from the movement of liquid metal in Mercury’s core. It is the only other rocky planet other than Earth to have this feature in the solar system.
Scientists were surprised to find this due to Mercury’s small size, which meant that any liquid metal inside would have been expected to cool quickly after it formed, but there definitely appears to be some liquid metal within the planet even today.
MESSENGER was launched in 2004 and spent a decade in space, orbiting Mercury for a total of four years. It has provided more data about hte planet than any other mission to date, sending vast quantities of data back to Earth until it ran out of fuel. The mission had only been meant to last a year.
