NASA's Juno reveals new image of rare crescent Jupiter & Ganymede's massive crater

It was in 2016 when the Juno probe reached Jupiter after a five-year-long journey and has been hovering around the gas giant and its moon ever since. Adding to its rich collection of data and photographs, the spacecraft has beamed back a couple of stunning images of Jupiter and its moon Ganymede. The Juno mission team revealed the images in a blog post on February 14, presenting Jupiter in a rare crescent phase (as shown in the image above).

"If you could ride along with NASA’s Juno spacecraft as it approaches Jupiter during one of its regular close passes by the giant planet, you would be treated to a striking vista similar to this one", the blog read. Moreover, it also said that spotting Jupiter in this phase from Earth is impossible even using a telescope. It is because Jupiter’s orbit is outside the Earth’s, so an observer on Earth can only see the side of Jupiter that is illuminated by the Sun, which would always present the planet in a complete form. The picture above was created using the JunoCam, which took seven images during Juno’s 39th close pass by Jupiter on January 12.

Juno snaps Ganymede's crater

(Ganymede's Kittu crater; Image: ASA/JPL-Caltech/SwRI/MSSS)

According to the mission team, the picture shown above was taken when Juno made a super close pass by the giant moon in June 2021. The probe reportedly was just 1,046 kilometres above Ganymede’s surface at its closest approach. The crater shown in the image is named Kittu and is approximately 15 kilometres across and is surrounded by darker material ejected during the impact that formed the crater. Surprisingly, most of Ganymede's craters emit bright rays, except for the 1%, which emit dark rays believed to be a result of contamination from the impactor. 

"As time passes, the rays stay dark because they are a bit warmer than the surroundings, so ice is driven off to condense on nearby colder, brighter terrain", the mission blog read. It is worth noting that Ganymede is even bigger than Mercury, which makes it the largest moon in the solar system. Besides, it is also the only moon known to have its own magnetic field and scientists are convinced that it has a massive ocean hidden underneath its icy surface. 

Image: NASA/JPL-Caltech/SwRI/MSSS