Mercury orbiters begin arrival after eight-year space flight

Two small orbiter spacecraft on Thursday separated from their carrier module and began their final approach to the planet Mercury after an eight-year flight, according to the European Space Agency. The orbiters are currently traveling together as one integrated unit, but will separate in December 2026, when they approach their orbit points and prepare to circle Mercury. One craft is European, and the other was manufactured by the Japan Aerospace Exploration Agency.

The orbiters are set to begin the science phase of their mission in April 2027. Both are packed with scientific instruments to gather data about the planet’s mysteries, according to the European Space Agency. The mission aims to discover why the planet has ice in its polar craters and why it has a magnetic field, among other questions.

The space agencies are using deep space antennas located in Spain and Argentina to keep track of the orbiters’ movements. The separation maneuver Thursday occurred more than 124 million miles away from Earth, the European Space Agency said.

Dig deeper: Read my report on NASA’s recent launch of a new space telescope.