Spacecraft drops spectacular new photos from just 102 miles above

The first images were received from a spacecraft that came within 102.5 miles (165 kilometers) of Mercury’s surface on September 4, its closest approach to the planet ever. The European Space Agency’s $1.8 billion probe, BepiColombo, took pictures of the planet’s polar regions and cratered surface during the approach.

The flyby is the seventh in the spacecraft’s long journey around the solar system (it has already been around Earth, Venus twice, and Mercury three times), and it is losing energy during its long and complicated journey as it enters orbit around Mercury. This latest flyby caused the spacecraft to slow down and change direction.

During the flyby, which ended at 21:48 UTC on September 4, BepiColombo took images and tested 10 science instruments, including measuring how the solar wind interacts with the planet’s magnetic field.

Joint Mission

BepiColombo is a joint European Space Agency and Japan Aerospace Exploration Agency (JAXA) mission to orbit Mercury. Launched in October 2018, the probe’s final orbital insertion is now scheduled for November 2026. This is an 11-month delay from the original schedule, due to a technical problem with the solar panels discovered in April that prevented the probe’s thrusters from operating at full power.

Polar Images

Flight engineers plan two more flybys of Mercury, in December and January 2025, as the probe tries to slow down to the same speed as the planet orbits the Sun. The spacecraft’s trajectory has been altered to accommodate Mercury’s orbit, which is tilted compared to Earth’s. This flyby also had the advantage that it was the first flyby that allowed BepiColombo to image both poles of Mercury. However, even if it does eventually reach Mercury, BepiColombo will need the thrust of its chemical propulsion engines to slow down enough to put MPO into orbit. Previous flybys of Mercury were conducted in June 2022 and June 2023.

Mission Objective

The flyby images, all black-and-white 1024-by-1024-pixel snapshots, were taken from three surveillance cameras onboard BepiColombo, which are primarily installed to monitor the spacecraft’s solar panels, antennas, and magnetometer boom.

BepiColombo is a modular spacecraft that will split into two halves upon arrival at Mercury: ESA’s Mercury Planetary Orbiter and JAXA’s Mercury Magnetospheric Orbiter, which will each enter a different orbit around Mercury. Together, the two probes will investigate the origin and evolution of Mercury, its internal structure, geology, composition, craters, atmosphere and magnetosphere (and their interaction with the solar wind), the origin of Mercury’s magnetic field, and study the deposits at Mercury’s poles. BepiColombo will also map Mercury at different wavelengths.

World-class science

“We are excited that BepiColombo, despite being in ‘stuck’ cruise mode, can advance our understanding and knowledge of Mercury with this short flyby,” Johannes Benkov, BepiColombo project scientist, said in a press release. “We can fly our world-class science laboratory through a diverse and unexplored part of Mercury’s environment that will be inaccessible once we’re in orbit, while at the same time preparing for a smooth transition to our main science mission as quickly as possible.”

Mercury Resonance

BepiColombo is named after the late Italian mathematician and engineer Professor Giuseppe (Bepi) Colombo, who discovered the resonance phenomenon that causes Mercury to rotate on its axis every two years.

This isn’t the first mission to Mercury: NASA’s Mariner 10 photographed the planet in 1974-75, and MESSENGER mapped it from 2008 to 2015.

May the clear skies and big eyes be with you.