SCIENCE COUNTDOWNS / ESA & JAXA / BEPICOLOMBO
BepiColombo enters Mercury's orbit
After years of flybys and braking, two science orbiters prepare to investigate a small planet with an outsized interior.
Until the published orbit-insertion date begins
WHERE THE MISSION STANDS
The threshold ahead.
BepiColombo carries ESA's Mercury Planetary Orbiter and JAXA's Mio magnetospheric orbiter. The transfer module separated in September 2026. The remaining spacecraft stack is preparing to enter Mercury orbit, after which the two science orbiters will separate and settle into their observing configurations.
Arrival is the beginning of a longer investigation. One spacecraft studies the planet while the other examines its magnetic environment. Putting those views together can help separate changes inside Mercury from changes driven by the Sun. Routine science operations follow the arrival and commissioning work.
WHY THE SCIENCE MATTERS
Questions worth returning for.
What does the interior leave on the surface?
Compare maps of landforms and composition with measurements that constrain the planet's interior. Craters are part of the record, but so are the processes that changed the crust. The challenge is to distinguish impact scars from evidence of the planet's own evolution.
What happens where the Sun meets a magnetic field?
Mio and the planetary orbiter can observe Mercury's magnetic environment from different positions. Comparing their measurements helps distinguish a changing external disturbance from a spatial structure that a single moving spacecraft passes through.
How does ice survive so close to the Sun?
Mercury has ice in permanently shadowed craters. Mapping polar terrain alongside temperature and composition measurements can sharpen the explanation of those cold refuges. The important boundary is sunlight and shadow, rather than a simple rule that proximity to the Sun makes every surface hot.
CONTINUE THE INVESTIGATION
Follow the thread.
Explore related investigations, Evidence Files, image stories and films.
DATE & SCIENCE SOURCES
ESA's October 6 arrival update gives November 21, 2026 for Mercury orbit insertion. The clock reaches 00:00 UTC at the start of that date; it is not a maneuver-time countdown. The orbiters are scheduled to separate on December 9–10, with the science phase beginning in April 2027.
Source review: October 10, 2026. Check the mission agency for later schedule changes.EXPLORE IN 3D / MAP 11
Approach the world BepiColombo will investigate
Explore Mercury’s mapped surface and the questions behind its terrain. The Atlas view gives planetary context; it does not display the spacecraft’s current position or simulate orbit insertion.
Open Mercury mapTHE NEXT FILES
Keep watching.
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The telescope has already seen starlight. Its next threshold is the orbit where its wide-field search can begin.
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