Skip to main content

NASA’s Juno spacecraft captures cool images of Jupiter’s huge moon

Image of Ganymede captured by NASA's Juno spacecraft in June 2021.
Ganymede captured by NASA’s Juno spacecraft during a June 7 flyby of Jupiter’s giant moon. NASA/JPL-Caltech/SwRI

NASA’s Juno spacecraft this week beamed back an exquisite image (above) of Ganymede, the largest moon in our solar system.

The image of one of Jupiter’s many moons was captured on June 7 during the closest flyby of Ganymede since Galileo passed by in 2000.

Taken by Juno’s JunoCam imager, it shows the water-ice-encrusted moon in astonishing detail, including numerous craters and a grooved terrain that in places is as high as 700 meters (2,300 feet) and possibly linked to tectonic faults.

Another image (right), this time captured by Juno’s Stellar Reference Unit star camera, offers an even closer view of the moon’s surface. This image is actually of Ganymede’s “dark side” (the side opposite to the sun), though sunlight reflecting off Jupiter made the capture possible.

The dark side of Ganymede, captured by Juno on a recent flyby. NASA/JPL-Caltech/SwRI

“This is the closest any spacecraft has come to this mammoth moon in a generation,” said Juno Principal Investigator Scott Bolton of the Southwest Research Institute in San Antonio. “We are going to take our time before we draw any scientific conclusions, but until then we can simply marvel at this celestial wonder.”

Dark side of the moon

“The conditions in which we collected the dark side image of Ganymede were ideal for a low-light camera like our Stellar Reference Unit,” said Heidi Becker, Juno’s radiation monitoring investigation lead at NASA’s Jet Propulsion Laboratory. “So this is a different part of the surface than seen by JunoCam in direct sunlight. It will be fun to see what the two teams can piece together.”

The space agency is aiming to use data from Juno to learn more about Ganymede’s composition, ionosphere, magnetosphere, and ice shell. The spacecraft is also gathering measurements of the radiation environment that could assist future missions to Jupiter and its moons, of which there are believed to be around 79.

Bolton said Juno, which reached Jupiter in 2016 after launching from Earth five years earlier, has with it a suite of scientific instruments that can examine Ganymede “in ways never before possible,” adding that the spacecraft’s ability to get so close “brings the exploration of Ganymede into the 21st century.”

Ganymede is the only moon with a magnetic field, which is known to cause auroras. The Hubble Space Telescope found evidence of a thin oxygen atmosphere on Ganymede in 1996, though it’s far too thin to support life as we know it, NASA said.

A tantalizing prospect is NASA’s promise of a color portrait of Ganymede comprising images taken by Juno on its latest flyby. The space agency is just waiting to gather all the data from Juno, which is currently around 435 million miles (700 million km) from Earth.

Editors' Recommendations

Trevor Mogg
Contributing Editor
Not so many moons ago, Trevor moved from one tea-loving island nation that drives on the left (Britain) to another (Japan)…
Watch NASA’s video teasing the reveal of Artemis moon astronauts
NASA's Orion spacecraft and Earth.

NASA is about to name the four astronauts who'll be sent on a flyby of the moon in a historic mission currently set for next year.

The space agency has just shared a cinematic trailer for the big reveal, which will take place at a special event on Monday, April 3.

Read more
NASA picks a commercial partner to visit the far side of the moon
Rendering of Firefly’s Blue Ghost lunar lander delivering NASA’s LuSEE-Night radio telescope to the far side of the Moon.

NASA has big plans for the moon. From sending the first crewed mission to land on its surface in 50 years to setting up a space station in orbit, the agency has multiple missions planned for exploring our planet's satellite. These include partnerships with a number of private companies as well as NASA-developed projects, such as under the Commercial Lunar Payload Services, or CLPS, program which will contract out the transportation of small payloads to the moon.

This week, NASA announced it has selected the company Firefly Aerospace to develop a commercial lander for the far side of the moon. The lander, called Blue Ghost, will be used to deliver several NASA payloads to the moon, including a radio observation mission which is placed on the far side of the moon to minimize the radio noise coming from Earth. This natural radio quiet zone will let the Lunar Surface Electromagnetics Experiment-Night (LuSEE-Night) telescope detect faint radio waves from an early period of the universe known as the cosmic dark ages.

Read more
Venus, Jupiter, and Ceres feature in NASA’s skywatching tips for March
how to photograph perseid meteor shower night sky with

NASA has just shared its monthly skywatching tips for March, helping us to better understand exactly what we’re looking at when we gaze upward toward a sea of celestial bodies -- provided it isn’t cloudy, that is.
Venus and Jupiter
At the start of this month, Venus and Jupiter appear close together in the night sky, and you can spot both with the naked eye. But as the days go by, the distance between the two planets will open up, with Venus climbing higher and Jupiter gradually heading in the opposite direction.

Jupiter will drop to such an extent that it’ll vanish from sight in the coming weeks. But in May it will return -- in the pre-dawn sky -- along with Saturn.
Moon and Venus
In its monthly update, NASA notes that on March 23 and 24, during the first couple of hours after sunset, the moon will be visible as a slim crescent close to Venus. On March 23 it appears just below the moon, while the very next night it’ll be just above. The following night, on March 25, the moon will its upward trajectory as viewed from Earth, appearing beside the brilliant Pleiades star cluster that evening.
Ceres
With this month seeing crop planting and harvesting activities in the Northern and Southern Hemispheres, respectively, NASA suggests the coming weeks as “a fitting time to try and spot the planet named for a mythical goddess of agriculture, grains, and fertile lands. (In addition to being the origin of the word ‘cereal.’)”

Read more