BepiColombo Makes Its Second Gravity Assist Flyby of Mercury

Jun 24, 2022 by News Staff

BepiColombo, a joint endeavor between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), captured beautiful views of the planet Mercury on June 23, 2022 as the spacecraft flew past the planet for its second gravity assist maneuver.

BepiColombo captured this view of Mercury on June 23, 2023 as the spacecraft flew past the planet for its second of six gravity assist maneuvers at Mercury. This image was taken at 09:51:07 UTC by the Mercury Transfer Module’s Monitoring Camera 3, when the spacecraft was 1,406 km from the surface of Mercury. Closest approach of 200 km took place shortly before, at 09:44 UTC. In this view, north is up. While clearly a heavily cratered region, this image also highlights some of Mercury’s volcanic history. Mercury’s smooth plains were formed by volcanic eruptions of runny lavas that spread across the planet 3.7 billion years ago -- such as the plains visible between BepiColombo’s high-gain antenna and towards Mercury’s limb. The eruptions that formed these plains did not commonly build volcanoes that we are familiar with on Earth. The floor of the 125-km-wide Heaney crater (next to BepiColombo’s high-gain antenna in the centre of this image) is covered in smooth volcanic plains, and a small mound is illuminated. This is a rare example of a candidate volcano on Mercury, which will be an important target for BepiColombo’s high resolution imaging suite once in orbit. North of Heaney, past the high-gain antenna, is the 105-km-wide Amaral crater with a clearly defined rim and a central peak cluster. The region surrounding Amaral is pockmarked with so-called secondary craters caused by material ejected from Amaral during its formation re-impacting onto the surface nearby. This texture is common around fresh craters on Mercury. Image credit: ESA / BepiColombo / MTM.

BepiColombo captured this view of Mercury on June 23, 2023 as the spacecraft flew past the planet for its second of six gravity assist maneuvers at Mercury. This image was taken at 09:51:07 UTC by the Mercury Transfer Module’s Monitoring Camera 3, when the spacecraft was 1,406 km from the surface of Mercury. Closest approach of 200 km took place shortly before, at 09:44 UTC. In this view, north is up. While clearly a heavily cratered region, this image also highlights some of Mercury’s volcanic history. Mercury’s smooth plains were formed by volcanic eruptions of runny lavas that spread across the planet 3.7 billion years ago — such as the plains visible between BepiColombo’s high-gain antenna and towards Mercury’s limb. The eruptions that formed these plains did not commonly build volcanoes that we are familiar with on Earth. The floor of the 125-km-wide Heaney crater (next to BepiColombo’s high-gain antenna in the centre of this image) is covered in smooth volcanic plains, and a small mound is illuminated. This is a rare example of a candidate volcano on Mercury, which will be an important target for BepiColombo’s high resolution imaging suite once in orbit. North of Heaney, past the high-gain antenna, is the 105-km-wide Amaral crater with a clearly defined rim and a central peak cluster. The region surrounding Amaral is pockmarked with so-called secondary craters caused by material ejected from Amaral during its formation re-impacting onto the surface nearby. This texture is common around fresh craters on Mercury. Image credit: ESA / BepiColombo / MTM.

BepiColombo blasted off from Europe’s Spaceport in Kourou, French Guiana, on October 20, 2018.

It is the first European mission to Mercury and is the first to send two spacecraft to make complementary measurements of the planet and its dynamic environment at the same time.

BepiColombo consists of two individual orbiters: ESA’s Mercury Planetary Orbiter (MPO) and JAXA’s Mercury Magnetospheric Orbiter (MMO, or ‘Mio’).

It will need nine gravity assist flybys — one at Earth, two at Venus and six at Mercury — before entering orbit around Mercury in 2025.

BepiColombo performed its first gravity assist of Mercury on October 1, 2021.

“Mercury flyby 1 images were good, but flyby 2 images are even better,” said Dr. David Rothery, a researcher at the Open University.

“The images highlight many of the science goals that we can address when BepiColombo gets into orbit. I want to understand the volcanic and tectonic history of this amazing planet.”

The closest approach during the second gravity assist maneuver took place at 09:44 UTC on June 23, 2022, about 200 km above the surface of Mercury.

Images from the spacecraft’s three monitoring cameras (MCAM), along with scientific data from a number of instruments, were collected during the encounter.

“We have completed our second of six Mercury flybys and will be back this time next year for our third before arriving in Mercury orbit in 2025,” said BepiColombo deputy spacecraft operations manager Dr. Emanuela Bordoni, a researcher at ESA.

BepiColombo captured this view of Mercury on June 23, 2023 as the spacecraft flew past the planet for its second of six gravity assist maneuvers at Mercury. This image was taken at 09:55:32 UTC by the Mercury Transfer Module’s Monitoring Camera 2, when the spacecraft was 2,862 km from the surface of Mercury. Closest approach of 200 km took place shortly before, at 09:44 UTC. In this view, north is approximately towards the top right. Some imaging artifacts such as horizontal striping are also visible. Parts of the Mercury Planetary Orbiter can be seen in the foreground: the magnetometer boom running from bottom left to top right in front of Mercury, and a small part of the medium-gain antenna at bottom right. This image represents BepiColombo’s first sighting of part of the 3.9 billion year old Caloris basin, which at 1,550 km across is the largest well-preserved impact basin on the planet. With the Sun above, the highly-reflective lavas on its floor make it easy to see as the bright semicircular area roughly between the 2 o’clock and 3 o’clock parts of the edge of Mercury’s disc. Caloris is surrounded by a halo of less reflective (darker) lavas. Both the interior and exterior lavas are thought to post-date the formation of the basin by a hundred million years or so, and measuring and understanding the compositional differences between these is an important goal for BepiColombo when it begins its main science mission in orbit around Mercury in 2026. Some of the small bright spots on the Caloris floor are impact craters with ‘hollows’ on their floors -- geological features unique to Mercury -- and others are deposits (‘faculae’) erupted explosively from volcanic vents that have punctured the basin-filling lavas from below. One prominent dark patch inside Caloris is a 100 km-wide impact crater called Atget that cut through the basin-filling lavas from above and excavated underlying ‘low reflectance material’ that may be a relict of Mercury’s early carbon-rich crust. Two other interesting craters lie between the spacecraft’s magnetometer boom and the left-hand edge of the frame: the young 24-km-wide crater named Xiao Zhao with its bright rays of ejected material, and a 260-km-wide peak-ring basin named Raditladi visible further north. The rich variety of craters and their associated features plots the impact history of the planet. Image credit: ESA / BepiColombo / MTM.

BepiColombo captured this view of Mercury on June 23, 2023 as the spacecraft flew past the planet for its second of six gravity assist maneuvers at Mercury. This image was taken at 09:55:32 UTC by the Mercury Transfer Module’s Monitoring Camera 2, when the spacecraft was 2,862 km from the surface of Mercury. Closest approach of 200 km took place shortly before, at 09:44 UTC. In this view, north is approximately towards the top right. Some imaging artifacts such as horizontal striping are also visible. Parts of the Mercury Planetary Orbiter can be seen in the foreground: the magnetometer boom running from bottom left to top right in front of Mercury, and a small part of the medium-gain antenna at bottom right. This image represents BepiColombo’s first sighting of part of the 3.9 billion year old Caloris basin, which at 1,550 km across is the largest well-preserved impact basin on the planet. With the Sun above, the highly-reflective lavas on its floor make it easy to see as the bright semicircular area roughly between the 2 o’clock and 3 o’clock parts of the edge of Mercury’s disc. Caloris is surrounded by a halo of less reflective (darker) lavas. Both the interior and exterior lavas are thought to post-date the formation of the basin by a hundred million years or so, and measuring and understanding the compositional differences between these is an important goal for BepiColombo when it begins its main science mission in orbit around Mercury in 2026. Some of the small bright spots on the Caloris floor are impact craters with ‘hollows’ on their floors — geological features unique to Mercury — and others are deposits (‘faculae’) erupted explosively from volcanic vents that have punctured the basin-filling lavas from below. One prominent dark patch inside Caloris is a 100 km-wide impact crater called Atget that cut through the basin-filling lavas from above and excavated underlying ‘low reflectance material’ that may be a relict of Mercury’s early carbon-rich crust. Two other interesting craters lie between the spacecraft’s magnetometer boom and the left-hand edge of the frame: the young 24-km-wide crater named Xiao Zhao with its bright rays of ejected material, and a 260-km-wide peak-ring basin named Raditladi visible further north. The rich variety of craters and their associated features plots the impact history of the planet. Image credit: ESA / BepiColombo / MTM.

Because BepiColombo’s closest approach was on the planet’s nightside, the first images in which Mercury is illuminated were taken at around five minutes after close approach, at a distance of about 800 km.

Images were taken for about 40 minutes after the close approach as the spacecraft moved away from the planet again.

As BepiColombo flew from the nightside to dayside, the Sun seemingly rose over the cratered surface of the planet, casting shadows along the terminator — the boundary between night and day — and highlighting the topography of the terrain in dramatic fashion.

“The new images show beautiful details of Mercury, including one of my favourite craters, Heaney, for which I suggested the name a few years ago,” said MCAM team member Dr. Jack Wright, a researcher at ESA’s European Space Astronomy Centre.

The 125-km-wide Heaney crater hosts a rare example of a candidate volcano on Mercury, which will be an important target for BepiColombo’s high resolution imaging suite once in orbit.

Just a few minutes after closest approach and with the Sun shining from above, Mercury’s largest impact feature, the 1,550 km-wide Caloris basin swung into view for the first time, its highly-reflective lavas on its floor making it stand out against the darker background.

The volcanic lavas in and around Caloris are thought to post-date the formation of the basin itself by a hundred million years or so, and measuring and understanding the compositional differences between these is an important goal for BepiColombo.

Share This Page