On July 4, NASA's Juno spacecraft fired its engines for the 35-minute orbit insertion burn. The spacecraft's nearly five year trek to Jupiter ended and its orbital mission began. It was an exciting moment for space nerds, but the casual observer might not have been thrilled. After all, we've been to Jupiter a number of times, and most people can recognize its characteristic red spot and know at least a little about its major moons. But as familiar as Jupiter might seem, Juno is only the second ever dedicated mission we've sent to the gas giant, this time around we stand to learn as much as Jupiter as how the elements for life ended up on Earth.
Scientists have presented further evidence for water plumes on the surface of Jupiter's moon Europa, raising hopes signs of life around the second planet from Earth. In a NASA press conference Monday afternoon, researchers involved in the Galileo mission and a recent reanalysis of the data revealed that the spacecraft may have flown right through a plume roughly 20 years ago, during its closest flyby. The new analysis suggests signatures once dismissed as'strange' disturbances in the magnetic field were actually signs of a plume – one that's'largely composed of water,' the researchers said during the conference. Europa's frozen surface has long been thought to cover a salty ocean about twice the size of our planet's. Given the suspected abundance of warm, liquid water under its kilometers-thick ice shell, the moon is considered a'top candidate' by NASA for life on a solar system body other than Earth.
Since July 2016, NASA's Juno spacecraft has often made headlines for its study of Jupiter -- the largest planet in our solar system -- and to a lesser degree, its moons. But a new research paper published Monday used data collected 20 years ago by the space agency's Galileo spacecraft to draw new conclusions about the gas giant's largest moon, Ganymede. Larger than Mercury and Pluto, and twice as massive as the moon we are familiar with here on Earth, Ganymede is the largest natural planetary satellite in the solar system. It is thought to have a large subsurface ocean, sandwiched between two layers of ice and possibly containing more saltwater than all the water in Earth's oceans. What makes Ganymede truly unique is its magnetosphere.
The spacecraft Juno made history Monday night. But before that, it captured footage of a phenomenon that has, until now, only existed in the human imagination: the serene trajectory of moons circling a planet. Juno's video, taken as the probe approached Jupiter, marks "the first time humanity's been able to see one celestial object go around another," Scott Bolton, Juno's principal investigator, told me. The objects, in this case, are the Galilean moons of Jupiter: Io, Europa, Ganymede, and Callisto. If it's not immediately clear why this is an awe-inspiring sight, some context might help.
Published yesterday in a paper for Nature Astronomy, a team of scientists led by Dr. Xianzhe Jia unveiled strong evidence that one of Jupiter's moons, Europa, is venting water into space in the form of plumes. This surprising result comes from anomalies uncovered in decades-old data from NASA's Galileo mission. Not only does this discovery showcase the importance of past archival data, but it also has critical implications in the search for extraterrestrial life. For years, Europa has been a promising candidate to host alien life due to its potential habitability. It is the 6th largest moon in the Solar System and boasts a thin, tenuous oxygen atmosphere as well as a magnetic field: important components of a habitable environment.