The second close flyby of Mercury by a spacecraft on Thursday June 23 yielded a stunning series of close-ups of the planet’s craters and volcanic regions.
The BepiColombo mission, a joint project of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), approached just 200 kilometers from Mercury’s crater-strewn surface.
While the closest view was of the night side of the planet, the scientists said the mission still provided valuable insight into Mercury’s formation processes when daylight regions appeared.
Related: Mercury looks stunning in this first flyby photo of Europe and the Japanese BepiColombo mission
“I hit the air when the first images dropped, and I got more and more excited after that,” said Jack Wright, who helped plan the imaging sequence as a member of the spacecraft surveillance camera team, in an ESA statement. (opens in a new tab).
“The images show beautiful details of Mercury, including one of my favorite craters, Heaney, which I suggested the name for a few years ago,” Wright added. (Heaney is among the craters in the annotated image below.)
Heaney is embedded in a set of smooth volcanic plains and may be located near an ancient volcano, which BepiColombo plans to examine more closely when it finally settles into orbit in 2025.
Minutes later, the spacecraft spotted the planet’s largest impact feature, called the Caloris Pool. The 970-mile (1,550 km) feature includes hardened lavas on the ground.
“The volcanic lavas in and around Caloris are thought to postdate the formation of the basin itself by around one hundred million years, and measuring and understanding the differences in composition between these is an important goal for BepiColombo” , ESA officials said in the same press release.
BepiColombo’s two orbiters are stacked on top of each other through the spacecraft’s various planetary flybys in the coming years. In this setup, ESA noted, only a selection of instruments are available for doing science.
That said, the mission was still able to examine the magnetic, plasma, and particulate aspects of Mercury in regions that won’t be visible from BepiColombo’s eventual orbit.
The spacecraft has four more Mercury flybys planned, with the next taking place in about a year. Next month, BepiColombo will make its closest approach to the mission sun.
Mercury is a difficult planet to reach, as the sun’s gravity accelerates any spacecraft in this region. BepiColombo performs the flybys to remove energy and speed from its trajectory in order to safely conclude its work in orbit.