A team of NASA scientists has analyzed the rocks collected from the surface of Mercury and concluded that the magnetic field of this planet was a lot stronger almost 4 billion years ago.
The scientists were able to analyze the samples with the help of NASA’s Messenger spacecraft.
The recent findings offer new perspective and help experts better understand the power source of Mercury’s magnetic field.
According to the researchers, the source of this magnetic field is the liquid dynamo that is well hidden in the outer core of Mercury.
Scientists have been aware of Mercury’s magnetic field since NASA’ Mariner 10 spacecraft discovered it during one of its space missions in the 1970s.
But no one knew for sure whether the magnetic field was a phenomenon that has existed for billions of years or it started more recently.
In 2011, NASA’s Messenger became the first ever spacecraft to ever orbit Mercury and its main goal was to come up with an answer to the question regarding the age of Mercury’s magnetic field.
Despite the fact that the Messenger has just landed on Mercury last week, scientists are still analyzing the data collected during the spacecraft’s four year journey orbiting around the planet, and discover plenty of fresh info.
Before the spacecraft ran out of fuel, the researchers used the last reserves in order to go down to very low altitudes and examine Mercury’s surface.
Messenger did not get closer than 200 km to the surface of the planet during its mission, but in the last month, the scientists were able to get the spacecraft to within almost 15 km of Mercury’s surface, which was the first time anyone has ever managed to get this close.
Catherine Johnson, an expert in geophysics from the University of British Columbia in Vancouver, Canada and one of the lead authors of the study, explained that getting this close was quite risky, mostly because, if the scientists got it wrong, they would have reached the planet too early.
Messenger managed to measure Mercury’s magnetic field using a tool called magnetometer. This is placed at the end of boom so that it won’t interfere with the spacecraft itself.
The spacecraft was able to measure the strength and the direction of the magnetic field at two of the sites on Mercury’s surface.
One of these sites that helped the team take the measurements is called Suisei Planitia, which is a large basin. Its name was chosen because it’s the Japanese word of Mercury.
Image Source: gizmag