Mercury — it’s a planet with frozen ice, a complicated magnetic field, and a surface filled with craters. Every mission there brings new mysteries. Fortunately, there’s a new spacecraft on the way shortly to solve some more dilemmas. On Friday, October 19, the European/Japanese BepiColombomission is set to launch to the closest planet to the sun. Scientists hope BepiColombo will teach us more about Mercury’s formation — and by consequence, show us more of the solar system’s history as well.
Getting the Basics Down
Mercury remains an enigmatic planet to us. So far, only one mission — NASA’s MESSENGER — has remained there for a substantial amount of time. While we lob spacecraft again and again to Mars to learn about our neighborhood’s history, it’s important not to forget studying other planets in the solar system. That would be like trying to study your family tree by only looking at the history of your grandmother.
The two spacecraft on the mission have a lot of work ahead of them in their one year at Mercury, which could be extended to a second year if scientists are lucky. Key questions include covering a lot of basics. Some examples: How did Mercury form, and evolve? Does Mercury have a solid or liquid core, and what elements are inside the planet? Is the planet still geologically and volcanically active today? What exactly is the nature of the water ice on the surface?
If you’re wondering why Mercury remains relatively unexplored, it’s a technology problem, according to the European Space Agency. The planet is so close to the sun that any spacecraft operating there must be able to endure similar temperatures to those on Mercury’s surface — as high as 400 degrees Celsius (750 degrees Fahrenheit). Also, it takes a lot of energy to move the spacecraft into the right orbit, which means that many planetary flybys are required to slow the two BepiColombo spacecraft down.
The Dynamic Duo
BepiColombo represents a really cool international collaboration because two spacecraft from two different space agencies are going to the planet together on the same rocket. The mission includes ESA’s Mercury Planetary Orbiter (MPO) and Japan’s Mercury Magnetospheric Orbiter (MMO). They’ll travel to the planet together for most of the journey before separating for different science missions.
Each spacecraft will look at different faces of Mercury’s environment. MPO scientists plan to image and map the entire surface of Mercury, showing us important details such as physical features and mineralogy (which help scientists trace Mercury’s origins.) Meanwhile, MMO will get a sense of the magnetic environment of Mercury, including a better understanding of how the planet’s magnetic shield interacts with the charged particles constantly flowing from the sun.
BepiColombo will make a bunch of planetary flybys to put it in the perfect position to insert itself into Mercury’s orbit — one flyby of Earth, two of Venus, and six of Mercury itself. This means that the first data from Mercury will flow back during a flyby in 2021, but BepiColombo won’t reach orbit until 2025. So we’ll have plenty of Mercury data to enjoy, starting next year.