The better our technologies get, the better we get at finding objects in space. That’s certainly true of Jupiter and its moons. Prior to Galileo, nobody knew the other planets had moons. Then in 1609/10, as he made improvements to his telescope, he aimed it at the gas giant and eventually found four moons: Io, Europa, Ganymede, and Callisto. Now those four natural satellites also bear his name: the Galilean moons.
Over the centuries since then, and especially in our digital age, astronomical tools and methods kept improving. In particular, wide-field CCD (Charge Coupled Devices) have led to an explosion of astronomical discoveries. In recent years, the confirmed number of Jovian moons has risen to 79. Now, a new study says that there may be 600 small irregular moons orbiting Jupiter.
The mysterious world Europa, the ice-covered second moon of Jupiter, sports deep scars that cut across its face. An international team of investigators studied high-resolution maps of that surface to reveal a pattern: something shook Europa sometime within the past few million years, causing the entire shell to shift by 70 degrees.
Ganymede’s surface is a bit of a puzzle for planetary scientists. About two-thirds of its surface is covered in lighter terrain, while the remainder is darker. Both types of terrain are ancient, with the lighter portion being slightly younger. The two types of terrain are spread around the moon, and the darker terrain contains concurrent furrows.
For the most part, scientists think that the furrows were caused by tectonic activity, possibly related to tidal heating as the moon went through unstable orbital resonances in the past.
But a new study says that a massive impact might be responsible for all those furrows.
About half of all the star systems in the galaxy are made of pairs or triplets of stars. Our solar system features just one star, the Sun, and a host of (relatively) small planets. But it was almost not the case, and Jupiter got right on the edge of becoming the Sun’s smaller sibling.
Jupiter, the biggest planet in the solar system, is by far the largest. If you added up the masses of all the other planets, it wouldn’t even come to half of the mass of Jupiter. You could eliminate every single planet in the solar system except Jupiter, and you would basically still have…the solar system.
It’s difficult to imagine the magnitude of storms on Jupiter. The gas giant’s most visible atmospheric feature, the Great Red Spot, may be getting smaller, but one hundred years ago, it was about 40,000 km (25,000 miles) in diameter, or three times Earth’s diameter.
Jupiter’s atmosphere also features thunderheads that are five times taller than Earth’s: a whopping 64 km (40 miles) from bottom to top. Its atmosphere is not entirely understood, though NASA’s Juno spacecraft is advancing our understanding. The planet may contain strange things like a layer of liquid metallic hydrogen.
Now a group of scientists are combining the power of the Hubble Space Telescope, the Gemini Observatory and the Juno spacecraft to probe Jupiter’s atmosphere, and the awe-inspiring storms that spawn there.
Though it looks like it to us, Jupiter’s clouds do no form a flat surface. Some of its clouds rise up above the surrounding cloud tops. The two bright spots in the right center of this image are much higher than the surrounding clouds.
The reign of Jupiter, named after the father of the Olympian gods, has been long and sweet. Aside from being the largest planet in the Solar System, it was this gas giant that demonstrated in the 17th century that planets other than Earth can support a system of moons. Between its size, powerful magnetic field, and system of 79 moons, Jupiter looked set to remain the king of the planets indefinitely.
But it looks like Saturn, named after the father of Jupiter in Greco-Roman mythology, might have just knocked Jupiter off that pedestal. Thanks to a team led by famed astronomer Scott S. Sheppard 20 new moons have been discovered orbiting Saturn. That brings the total number of Saturnian (or Cronian) satellites to 82, putting it ahead of Jupiter’s 79. And the best part? You can help name them!
In a death-defying maneuver for the spacecraft, NASA’s Juno has completed an unprecedented and unplanned engine burn. The purpose? To save the spacecraft’s “life,” or at least the rest of its mission to Jupiter.
Jupiter casts a deep, dark shadow. Dark enough, in fact, to effectively kill Juno if it flies through it. Rather than let the spacecraft spend 12 battery-draining hours in Jupiter’s shadow, and then attempt a risky resuscitation on the other side, NASA took another course of action: a 10.5 hour burn of Juno’s reaction thrusters that will steer it clear of Jupiter’s life-draining shadow.