The Juno probe, launched by the National Aeronautics and Space Administration (Nasa), a branch of the US federal government, has travelled over five years and more than 2.7 billion kilometres to enter the orbit of the planet Jupiter on 4 July 2016. According to a statement released by Nasa on the day of the launch, the name of the probe stems from Greek and Roman mythology: “The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter’s true nature.”
The probe resembles a windmill and is powered by three elongated solar arrays stretching away from its rotating body. Once the probe entered Jupiter’s orbit it gained immense speed, and will not run out of energy but rather risks over exposure to radiation. For this reason, the Juno probe resides in a radiation vault of 1.2 cm-thick titanium walls. If the probe survives then it will spend the next 20 months attempting to successfully orbit Jupiter 37 times. The probe will also sweep closer to the clouds surrounding Jupiter than any other spacecraft previously has; it will dive near the clouds, at a distance of about 5 000 kilometres, every two weeks.
The goal of the mission is to discover the truth about the first planet that formed in our solar system. This involves discerning the planet’s origin, exploring the intense radiation fields, and learning more about the magnetic fields that surround Jupiter and cause magnificent auroras that are hypothesized to be the result of a strange exotic form of molten hydrogen.
According to the principle investigator of the mission, Scott Bolton, Jupiter holds a unique position because it can reveal what the Earth consists of, as it is theorised that Jupiter has similar conditions and structures to that of Earth. He says, “Learning about that history is really critical to figuring out how we got here and how we find other systems like ours elsewhere.”
An important factor of this is uncovering liquid water on Jupiter and by extension its levels of oxygen. It has been suggested that Jupiter is made up of 99% helium and hydrogen with slight amounts of ammonia, however the probe could produce results that suggest otherwise. This is why the Juno probe is important, as it shows promise of providing a better understanding of the composition of the Jupiter’s core, about which very little is currently known.
The probe makes use of eight different instruments that will only be activated once it has stabilised within the magnetic fields of Jupiter. One of these instruments is JunoCam, which will provide never-before-seen images of Jupiter. However, the life expectancy of JunoCam is only 7-8 orbits before the high levels of radiation exposure are expected to destroy it. The images captured will not only be accessible by the public but will also be involved in various activities that will encourage public participation. From a more scientific approach, the images will be used to learn more about Jupiter and its surroundings, specifically the moons of the planet. A voyage to explore one of Jupiter’s moons named Europa is already in motion for 2020. The moon boasts icy conditions and a subsurface ocean that may contain life.
The Juno probe is never destined to return to Earth; after two years it will dramatically plunge into Jupiter once its mission is complete so that it does not contaminate any of the surrounding moons or other outer space material. It appears that the fifth planet from the sun may play a key role in furthering our understanding of our home planet.