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A European spacecraft will be getting to know the planet Mercury quite well later in the decade. Today, though, it’s scheduled to get a brief introduction. It will fly past the Sun’s closest planet — the first of six close encounters before it enters orbit in several years.
BepiColombo actually consists of two spacecraft. They’re being carried by a shell that provides electricity and rocket power. They’ll head their separate ways when they begin orbiting Mercury.
The two probes are designed to study Mercury’s composition, structure, and magnetic field. They should tell us whether the planet’s interior is molten or solid. And they’ll tell us more about the little world’s history.
Only two other spacecraft have ever visited Mercury. In part, that’s because it’s a tough planet to snuggle up to. The Sun’s gravity accelerates a spacecraft that heads toward Mercury, so it takes a lot of effort to slow it down. That consists mainly of using the gravity of Mercury and other planets as brakes.
BepiColombo has already flown by Earth once and Venus twice, molding its orbit with each encounter. The passages by Mercury will help even more. But it’ll take a lot of “braking” before BepiColombo can settle into orbit in 2025.
The craft will make some observations of Mercury with each pass. And each brief encounter should add to our knowledge of the smallest planet in the solar system — a world that’s hard to get close to.
Script by Damond Benningfield