Our Galileo spacecraft took this false-color mosaic, constructed from a series of 53 images, as the spacecraft zoomed over the northern regions of our Moon on December 7, 1992. The spacecraft was on its way to Jupiter.
The mosaic helps us see variations in parts of the Moon's northern hemisphere. Bright pinkish areas are the lunar highlands, including the ones surrounding the oval lava-filled Crisium impact basin toward the bottom of the picture. Blue-to-orange shades indicate ancient volcanic lava flows.
To the left of Crisium is the dark blue Mare Tranquillitatis, where Apollo 11 landed. It’s richer in titanium than the green and orange areas above it. Thin mineral-rich soils associated with relatively recent meteorite or asteroid impacts are represented by light blue colors; the youngest craters have prominent blue rays extending from them.
The Galileo probe, named for the Italian astronomer who discovered Jupiter’s four largest moons, orbited the gas giant from 1995 to 2003. Its camera and nine other instruments helped scientists make numerous discoveries, including one that indicates the planet's icy moon Europa likely has a subsurface ocean. Galileo's successor mission, Juno, is currently exploring the Jovian giant to help us understand the origins of our solar system.
JUPITER
nasa What causes X-ray auroras on Jupiter? Ions "surfing" electromagnetic waves! ⚛️ 🌊
Jupiter has the most powerful auroras in the solar system, and is the only one of the four giant planets with an aurora that has been found to emit X-rays. Planetary astronomers knew the auroras are triggered by ions crashing into Jupiter’s atmosphere. Now, they have learned how the ions responsible for the X-ray light show are able to get to the atmosphere.
Scientists combined measurements taken by our Juno spacecraft with data from the @EuropeanSpaceAgency's XMM-Newton mission, to solve a 40-year-old mystery about the origins of Jupiter’s unusual X-ray auroras. For the first time, they have seen the entire mechanism at work: The electrically charged atoms, or ions, responsible for the X-rays are “surfing” electromagnetic waves in Jupiter’s magnetic field, down into the gas giant’s atmosphere.
The purple hues in this image show the X-ray emissions from Jupiter’s auroras, detected by our Chandra X-ray Observatory in 2007. They are overlaid on an image of Jupiter taken by our Hubble Space Telescope.
Pluto
nasa We’re having a Pluto party, we didn’t even planet 🥳
Six years ago @NASASolarSystem New Horizons spacecraft made history with the first up-close exploration of the Pluto and its largest moon, Charon.
Zipping by at more than 30,000 miles per hour during its historic flyby on July 14, 2015, the spacecraft gathered some of these sharp images and topographic data:
📸View the rainbow of pale blues, yellows, oranges and deep reds that make up Pluto’s Surface, evidence of a complex history scientists have only begun to decode.
📸 Peer into Pluto's blue haze, a high-altitude layer that likely involves sunlight initiating chemical reactions of nitrogen and methane and leading to small soot-like particles that settle towards the surface.
📏Famously petite, Pluto is about 5.5 times smaller than Earth. Side by side, both Pluto and Charon would barely span the United States. Charon, with a diameter of 753 miles, is the largest moon relative to its parent planet – Pluto has a diameter of 1,477 miles.
