Bound for Planet Mercury: BepiColombo Aims to Solve Tiny Planet’s Mysteries

Bound for Planet Mercury: BepiColombo Aims to Solve Tiny Planet’s Mysteries

This past weekend, the BepiColombo spacecraft showed off an epic last view of Earth before zooming off toward the inner solar system.

This past weekend, the BepiColombo spacecraft showed off an epic last view of Earth before zooming off toward the inner solar system.

Amid the COVID-19 pandemic affecting nearly every continent on the planet, the moment was not lost on the European Space Agency.

“Images gathered just before closest approach portray our planet shining through darkness, during one of humankind’s most challenging times in recent history,” the ESA said in a statement.

For BepiColombo, however, a joint mission of the ESA and Japan Aerospace Exploration Agency, these glorious images are seen as only the appetizer for what is to come.

The solar-powered BepiColombo is expected to enter Mercury’s orbit in 2025, and when it does, the mission will focus on performing a comprehensive study of the planet, which includes the characterization of its magnetic field, magnetosphere and both the interior and surface structure.

Before BepiColombo, the only spacecraft to have visited the innermost planet were NASA’s Mariner 10 and MESSENGER missions.

For decades, Mercury, only a little larger than our moon, has been viewed as a peculiar planet, one in which its surface temperatures rise up to a blistering 850 degrees Fahrenheit, yet there seems to be a presence of water ice inside craters around the planet’s poles. The rocky planet also appears to have a much too large inner core relative to its size and possesses a surprising chemical composition.

This is where BepiColombo and its high-tech instruments come in, and hopefully, provide much-needed answers that have eluded scientists.

Some scientists have postulated that Mercury’s current 88-day elliptical orbit around the sun wasn’t always so. Data from the MESSENGER spacecraft showed that there is too much of the volatile chemical element potassium, as compared to the more stable radioactive thorium, in the material that makes up Mercury’s surface.

One theory is that there was a huge impact in the distant past, which pushed Mercury to where it is today. This particular event also likely stripped away most of the crustal material, leaving behind a dense core and a thin outer layer. Some have even hypothesized that an ancient Mercury struck Earth some 4.5 billion years ago, a cataclysmic collision that led to the eventual formation of the moon.

Two other important questions deal with Mercury’s dark color and whether it has a magnetic field. Mercury appears much darker than our moon, and in an effort to understand why, BepiColombo’s thermal infrared spectrometer will once and for all create a detailed map of the mineral distribution on the surface.

As for the magnetic field, only Mercury and Earth have one among the rocky planets of the inner solar system. Mars is thought to have had a magnetic field in the past but lost it. Mercury, though, appears too small to have one, and in comparison to Earth’s magnetic field, it is a hundred times weaker. It will be up to BepiColombo to find out what sustains this magnetic field on tiny Mercury.

Ethen Kim Lieser is a Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV.