Eight Years in Space! A Spacecraft Just Took Its First Big Step Toward Mercury
Quick Summary
A spacecraft called BepiColombo has been flying through space for eight years. Today, it completed a key step on its way to Mercury — the planet closest to the Sun. Scientists around the world are watching closely as it prepares to enter orbit.
What Happened?
On September 3, 2026, a big moment happened far out in space. BepiColombo is a joint mission run by two space agencies: ESA (from Europe) and JAXA (from Japan). Together, they built a spacecraft and launched it way back in October 2018.
For eight years, the spacecraft traveled across the inner solar system. It covered more than 6 billion miles — that’s like going around Earth 240,000 times! All that distance, just to reach tiny Mercury.
Today, a piece of the spacecraft called the Mercury Transfer Module separated from the two science orbiters it was carrying. Think of it like a rocket-powered backpack that did all the heavy lifting for the trip. Once the backpack’s job was done, it detached and floated away. The two real science spacecraft — one European and one Japanese — are now on their own for the final steps.
But the mission isn’t over yet! The two orbiters won’t actually slip into Mercury’s orbit until November 2026. After that, they will separate from each other in December. Real science work won’t begin until April 2027.
Why did it take so long to get there? Mercury is actually not that far away compared to the outer planets. The problem is that Mercury moves extremely fast around the Sun — about 107,000 miles per hour! To land in orbit, the spacecraft had to carefully slow down to match Mercury’s speed. That takes many loops around planets to bleed off energy, like a roller coaster that slowly brakes to a stop.
BepiColombo is named after Giuseppe “Bepi” Colombo, an Italian scientist who figured out clever ways to fly to Mercury using gravity as a steering tool back in the 1970s.
Why Does It Matter?
Mercury is one of the least-explored planets in our solar system. Only two other spacecraft have ever visited it before. Scientists still have big questions about Mercury: What is it made of? How did it form so close to the Sun? Why does it have a magnetic field when it is so small?
One of the weirdest things BepiColombo will investigate is Mercury’s strange surface holes called “hollows.” These are pits that look like the surface is slowly being eaten away — and nobody knows exactly why. No other planet in our solar system has them!
The two orbiters carry many tools. They will map Mercury’s surface, study its magnetic field, and investigate the thin cloud of gas that surrounds it. Everything they find could teach us how rocky planets like Earth were born.
Big Words
- Orbit — the curved path an object follows as it travels around a planet or star, like the Moon orbiting Earth
- Transfer module — the powerful engine section of a spacecraft that provides energy for a long journey through space, then gets released when no longer needed
- Gravity assist — a space travel trick where a spacecraft swings past a planet to gain or lose speed, like borrowing a push from the planet’s own motion
- Exosphere — an extremely thin layer of gas around a planet; Mercury’s exosphere is so thin that its particles almost never touch each other
- Orbiter — a spacecraft designed to circle a planet and study it from above, without landing
Fun Fact
Mercury is the smallest planet in our solar system, about as wide across as the continental United States — yet it has one of the largest iron cores of any planet, making up about 85% of its radius!
Think About It
Mercury is actually closer to Earth than Jupiter is, yet BepiColombo took longer to reach it than some missions have taken to reach Jupiter. Why do you think it might be harder to reach a nearby planet that moves super fast than a farther planet that moves slowly?
Sources
- ESA — Watch live: BepiColombo begins its arrival at Mercury
- CNN / KEYT News Channel 3-12 — The BepiColombo mission begins its arrival at Mercury after nearly 8 years
- Space.com — 2 spacecraft headed to Mercury are about to begin their long-awaited arrival for Europe and Japan
- Time.news — BepiColombo Enters Complex Mercury Orbit in Historic Arrival Phase