Look towards the north-west after sunset and there is currently one bright point of light that easily stands out relative to everything around it. That is the planet Jupiter, shining with an intense and steady glow.
After a journey of five years, and decades in the planning, NASA's Juno spacecraft has achieved orbit around Jupiter. Soon begins the next stage in humanity's quest to explore the largest of the gas giants in our solar system. But what do we know of Jupiter to date?
Brightest, biggest, first
Jupiter's brightness in the night sky is due to its enormous size. It is by far the biggest planet of the solar system, containing more than double the mass of all the other planets, moons, comets and asteroids combined.
Its great size suggests that Jupiter was also the first planet to form around the sun. The planets emerged out of the debris left over when an interstellar cloud of gas and dust coalesced to form our star. Early in its life, the young sun generated a wind that blew away most of the remaining interstellar cloud, but Jupiter was able to hold on to that history.
Locked up in Jupiter, therefore, is the recipe for how a solar system is made – the ingredients from which the planets and other smaller bodies came to be, and the processes and conditions that enabled this material to come together to form such amazing and diverse worlds.
King of the planets
Jupiter, along with Mercury, Venus, Mars and Saturn, have all been observed since ancient times as they are easily visible in the night sky. Different cultures who studied the stars also realised that these objects were unique; they did not stay fixed in their relative patterns or constellations as the stars did but moved according to different rules.
They were referred to as the wandering stars by the ancient Greeks and derived from this term came the name planet.
It is remarkable just how aptly Jupiter is named. We are now aware that Jupiter is the largest and most massive of the planets so it is fitting to be named for the Roman king of the gods, who was also the god of the sky. While in Greek mythology, Jupiter's counterpart is Zeus, the supreme god of ancient Greece.
The next 18 months are set to be very interesting as the Juno spacecraft increases our understanding of the great gas giant, Jupiter.