JUNO probe successfully completes first Jupiter flyby
A flyby of planet Jupiter at a speed of more than 200 thousand kilometres per hour, up to a distance of about 4,200 kilometres from the surface of the gas giant. This is the target reached on 27 August by JUNO, NASA’s mission that has Italy as the main partner of the US Space Agency.
About 4,200 kilometres above Jupiter’s swirling clouds, reaching the closest approach to the planet at 15:44 (Italian time) on Saturday 27 august 2016, travelling at a speed of more than 200 thousand kilometres per hour and collecting the first precious data on the gas giant. This important result was achieved by JUNO (JUpiter Near-polar Orbiter), the probe launched in August 2011 by NASA with the aim to reach ‒ and study the origin and evolution of ‒ the fifth planet of the Solar System: Jupiter.
Italy participated in the project by developing two important onboard instruments: the next generation JIRAM spectrometer (Jupiter InfraRed Auroral Mapper), provided by the Italian Space Agency and developed with the scientific support of the Italian National Institute for Astrophysics (INAF), and the radio science instrument KaT (Ka-Band Translator), developed by Thales Alenia Space Italia and able to provide precious information on the planet’s inner core.
After a journey of about three billion kilometres that lasted about 5 years, the JUNO probe entered into orbit around Jupiter on 4 July. The 27 August flyby was the first of more than 35 flybys planned during the mission, which is scheduled to end in February 2018. During its approach to the planet, the probe sent back a handful of images, with a view of the Jupiter’s north pole taken at a distance of about 703 thousand kilometres (right).
The primary scientific goal of the JUNO mission is to analyse the characteristics of Jupiter as the archetypical giant planet, by studying its internal structure, magnetic field, water abundance, the influence of atmospheric winds and even “weight”. Weight, in particular, can provide key information useful to better understand the origin of the Solar System and analyse in detail the characteristics of other newly discovered planetary systems with mass similar to that of Jupiter.
The first significant images of the planet were captured by JIRAM, one of two key Italian instruments onboard the US spacecraft, designed to study the dynamics and chemistry of the Jovian auroras in the near infrared. “JIRAM is getting under Jupiter’s skin – explains Alberto Adriani, researcher at INAF and Principal Investigator of the instrument – giving us our first infrared close-ups of the planet. These first infrared views of Jupiter’s north and south poles are revealing warm and hot spots that have never been seen before. And while we knew that the first-ever infrared views of Jupiter’s south pole could reveal the planet’s southern aurora, we were amazed to see it for the first time. No other instruments, both from Earth or space, have been able to see the southern aurora. Now, with JIRAM, we see that it appears to be very bright and well-structured. The high level of detail in the images will tell us more about the aurora’s morphology and dynamics ”, the researcher added.
“The results of JIRAM calibrations obtained in early August – says Barbara Negri, Head of ASI’s Earth Observation Unit – showed that the instrument is working as expected and scientific activity started after the first close flyby of Jupiter. This is further confirmation of the ability of Italian scientific and industrial teams to build this kind of instruments, which are of great importance for the exploration of our Solar System”.