The large Vivaldi crater contains a ring basin filled with peaks – ESA/JAXA
September 6 () –
The ESA/JAXA BepiColombo mission has successfully completed its fourth of six flybys with gravity assistance on Mercury, the closest to the Sun, and which has provided unique views.
The maneuver has allowed it to take images of two special impact craters while using the gravity of the small planet. to head into orbit in November 2026, eleven months later than planned due to electric propulsion problems that have been resolved with a change of trajectory.
The closest pass occurred at 21:48 UTC on 4 September, when BepiColombo descended to about 165 km above the planet’s surfaceFor the first time, the spacecraft had A clear view of Mercury’s south pole.
“The primary objective of the flyby was to reduce the speed of BepiColombo relative to the Sun, so that the spacecraft would have an orbital period around the Sun of 88 days, very close to the orbital period of Mercury,” he says. in a statement Frank Budnik, director of flight dynamics at BepiColombo.
“In this sense, it was a great success and we are right where we wanted to be at this point. But it also gave us the opportunity to take pictures and carry out scientific measurements.” from places and perspectives we will never reach once we are in orbit.”
Images from the three BepiColombo monitoring cameras provide a unique view of Mercury’s surface from three different anglesBepiColombo approached Mercury from the planet’s “night side,” with Mercury’s cratered surface increasingly illuminated by the Sun as the spacecraft flew by.
M-CAM 2 provided the best views of the planet during this flyby, capturing more and more detail of the planet as BepiColombo approached the sunlit side of Mercury. M-CAM 3 also provided a stunning image of a newly named impact crater. M-CAM 1 operated for longer to capture the planet’s retreat.
Four minutes after closest approach, BepiColombo saw a large “peak ring basin”. These mysterious craters, created by powerful asteroid or comet impacts and measuring between 130 and 330 km wide, are called peak ring basins because of the inner ring of peaks on an otherwise flat floor.
The images show the Vivaldi craternamed after the famous Italian composer Antonio Vivaldi (1678-1741). It is 210 km wide and, as BepiColombo saw it so close to the sunrise line, its landscape is beautifully emphasised by the shadow. There is a visible gap in the ring of peaks, through which more recent lava flows have entered and flooded the crater.
A couple of minutes later, another special peak-ring basin appeared. This crater measures 155 km in diameter.
“When we were planning this flyby, we saw that this crater would be visible and we decided that It would be worth naming it because of its potential interest to BepiColombo scientists in the future.” explains David Rothery, Professor of Planetary Geosciences at the Open University in the UK and a member of BepiColombo’s M-CAM imaging team.
Following a request from the M-CAM team, the International Astronomical Union’s Working Group on Planetary System Nomenclature recently renamed the ancient crater Stoddart in honor of Margaret Olrog Stoddart (1865-1934), a New Zealand artist known for her flower paintings.
“Mercury’s spike ring basins are fascinating because many aspects of how they formed remain a mystery today. The spike rings are presumed to be the result of some sort of rebound process during the impact, But the depths from which they rose are still unclear,” David continues.
Many of Mercury’s ring-top basins have been inundated by volcanic lava flows long after the original impact. This has happened in both Vivaldi and Stoddart’s interiors. Inside Stoddart, the trace of a 16 km wide crater that must have formed on the original floor It is clearly visible through a cover of more recent lava flows.
The ring basins of the cimas are among the high-priority targets for BepiColombo to study once it enters orbit around Mercury. and can deploy its full suite of scientific instruments.
The snapshots seen during this flyby are among the best from BepiColombo yet, taken from the closest distance yet, with Mercury’s surface well illuminated by the Sun. They reveal a surface with clear signs of 4.6 billion years of asteroid and comet bombardment, giving a clue to the planet’s place in the wider evolution of the Solar System.
In 2027, the main scientific phase of the mission will begin. The spacecraft’s suite of scientific instruments will reveal the invisible about the most mysterious planet in the Solar System, to better understand the origin and evolution of a planet close to its host star.
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