New findings recorded by MESSENGER spacecraft, has revealed that the magnetic field of Mercury was formed about four billion years ago. The findings have been published in the journal Science, and reveals that the field’s power source originated from the liquid dynamo in the planet’s outer core.
Since 1970’s scientists have known that Mercury carried a magnetic field, after NASA’s Mariner 10 spacecraft detected it. However, they remained unsure if the magnetic field was short-lived or a long-term phenomenon. The MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft was launched in 2004 and reached Mercury, seven years later.
“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,” said Catherine Johnson, a planetary scientist at the University of British Columbia
The research on the planet was carried on for four years, three years more than the mission period of 12 months. Mercury was formed along with the Sun and the Solar System, about 4.4 billion years ago. According to the data recorded by a magnetometer about the observatory, the magnetic field on the planet was found to be formed about 3.7 and 3.9 billion years ago.
However, magnetism in the rocks and crust were weak to be recorded from higher orbit. Though Mars and Venus do not possess a magnetic field, scientists believe that the red planet could have had a magnetic field 3 billion years ago. MESSENGER is the spacecraft to visit the planet. The spacecraft made around 4,000 orbits before it crashed on the planet on April 30, 2015.
The first visit to the planet was made by Mariner 10, which explored the innermost solar system from 1962 to 1973. More details and analysis of the newly discovered magnetic field can be found in the journal Science.[ Via ]