Juno leaves for Jupiter

• NASA launched the billion-dollar solar-powered spacecraft Juno on a five-year journey to Jupiter.
• The unmanned satellite observatory shot into space aboard a 197-foot-tall (60 metres) Atlas V rocket, blasting off from the Cape Canaveral Air Force Station in Florida at 12:25 p.m.
• Once it arrives in July 2016, the spacecraft will orbit the poles of the gas giant, which has more than twice the mass of all planets in the solar system combined and is believed to be the first planet that took shape around the Sun.
• Named after the wife of the Roman god Jupiter, the $1.1 billion spacecraft is NASA's first mission to the planet since Galileo was launched in 1989. It aims for 30 orbits over a period of one year.
• Juno will get closer to Jupiter than any other NASA spacecraft has and will be the first to undertake a polar orbit of the planet, said Scott Bolton, Juno principal investigator and scientist at the Southwest Research Institute in San Antonio, Texas.
• Juno is set up to learn about that early part of the solar system and learn how Jupiter formed and by measuring the ingredients.
• The orbiter Galileo entered the planet's orbit in 1995 and plunged into Jupiter in 2003, ending its life.
• Other NASA spacecraft — including Voyager 1 and 2, Ulysses and New Horizons — have done flybys of the planet.
• Juno will spend the first two years of its mission going around the Sun, then return for a flyby of the Earth, which will give a gravitational boost to accelerate the spacecraft on a three-year path toward Jupiter.
• When it gets there, Juno — orbiting around 5,000 km (3,100 miles) above the gas giant — will make use of a series of instruments, some of which were provided by European space agency partners in Italy, Belgium, France and Denmark, to learn about the workings of the planet and what is inside.
• Two key experiments will gauge how much water is in Jupiter and whether the planet "has a core of heavy elements at the centre, or whether it is just gas all the way down," Mr. Bolton said at a press briefing last week.
• Scientists also hope to learn more about Jupiter's magnetic fields and its Great Red Spot, a storm that has been raging for more than 300 years.
• Juno is part of a series of new planetary science missions, to be followed by GRAIL (Gravity Recovery and Interior Laboratory), which is headed to the moon in September, and the Mars Science Laboratory set to take off in November.