After a five year journey, which started on August 5, 2011, the Juno spacecraft arrived in the orbital outskirts of the largest planet in the Solar System on July 4, 2016. The spacecraft set itself as the continuing factor of a period of discovery, following in the technological footsteps of its predecessor, Galileo, which orbited and studied the giant red planet from December 7, 1995 to September 21, 2003. The name “Juno” was given in recognition of the Roman goddess who acted as the protector and special counselor of the state of Rome. She was also the sister and wife of the chief Roman god Jupiter. According to Latin mythology, Jupiter, being the chief god, was also described as one who would be up to mischief at times and practiced cloaking himself in immense clouds to hide his actions. Juno, however, was wise and was able to see through and beyond the clouds to always have a clear vision of her husband’s actions. Such symbolism fits the nature of this scientific exploration as Juno’s “reunion” with her husband can once again help us understand more about the king of planets and cause us to step even closer to understanding space itself.
Galileo – the trendsetter
Before Juno there was Galileo. Its development was inspired by the works of the Pioneer and Voyager space programs of the 1960’s and 1970’s respectively. Pioneer 10 and Pioneer 11 became the first known spacecrafts to do atmospheric flybys of Jupiter, sending some of the first known pictures of the planet. A decade later, Voyager I and Voyager II also did flybys with increased advancements, resulting in higher resolution pictures being produced, many of which ended up in textbooks and research papers in academic institutions throughout the world. However, many of the images were only partial in nature, showing small parts of the planet, and much information concerning Jupiter’s atmospheric concentration, dimensions and terrestrial constitution was still yet to be known and clarified/enhanced. This then led to the introduction of the Galileo space program, named after Italian astronomer Galileo Galilei, who discovered the four largest moons of Jupiter (although, historically, this has been debated). Galileo became the first spacecraft to orbit Jupiter, repeating the cycle for 8 years until its termination in 2003. From these orbits in the Jovian system (‘Jovian’ refers to the system involving Jupiter and its moons) much information was obtained pertaining to the composition of Jupiter’s atmosphere and its internal core and dimensions. Information was also obtained concerning Jupiter’s 67 known moons, include the four large Galilean moons; Europa, Io, Callisto, and the largest moon in the Solar System , Ganymede. The Galileo spacecraft helped to discover and achieve the following:
- Jupiter consisted of clouds which were primarily made from Ammonia.
- The surface of Europa consisted of ice and data collected showed the possibility of a liquid ocean under the layer of ice.
- Ganymede and Io had underlying layers of liquid saltwater, with Io also exhibiting volcanic activity and plasma interactions with Jupiter.
- Exospheres were discovered surrounding Ganymede, Callisto and Europa, with Ganymede also having its own magnetic field (just like earth- hence the north and south poles).
- The constituents of Jupiter’s faint ring were discovered and Jupiter’s magnetic fields were mapped for the first time.
Jupiter itself got a grand unveiling by the orbits of Galileo. However, with its services being terminated over a decade ago, much information was still yet to be known about Jupiter.
Juno’s main task is to be a worthy follow up and a better pair of glasses, per say. After completing its 1.7 billion mile journey, it conducted a photographic capture of Jupiter and its four largest moons over a 17 day period, before lodging itself into Jupiter’s orbit. The video below shows a time lapse of Juno’s photographs, giving scientists their first view of planetary motion in action (video courtesy NASA).
Juno aims at building on the work done by Galileo as well as going beyond what its predecessor could have ever achieved. Juno’s primary objectives are:
- To conduct in-depth studies on Jupiter’s composition, gravity field, magnetic field, and polar magnetosphere.
- To search for clues concerning the planet’s formation, including the structure of its core, the presence of water within its deep atmosphere, its mass distribution (which affects its physics and mechanics), and its deep winds (which can reach at speeds of almost 400 mph).
Juno also hopes to do much research of Jupiter’s moons, primarily Ganymede and Europa, the latter of which has been the talk of many scientists and conspiracy theorists in relation to the presence of water and the existence of extra-terrestrial life. Juno’s order is a somewhat tall one, but it is one that we are eager to see the results of.
Space Travel’s future
Juno isn’t the end of the prospects of exploration. Plans have already been initiated and are still under way for even grander and deeper explorations into the depths of space. Juno is expected to conduct 37 orbits over the space of 24 months, with each orbit around Jupiter lasting 53 days, each having a highly elliptical pattern. This means that (1) at the moment, much information might not be received from the craft until mid August as it is currently on the path of the orbit furthest away from the planet, and (2) this would result in the spacecraft’s operations ceasing in February 2018. At that time, NASA will conduct a controlled deorbit into Jupiter, disposing of the spacecraft. Innovation and exploration would therefore not cease with Juno. On July 14, 2015, the New Horizons space probe flew 12,500 km above the surface of Pluto, making it the first spacecraft ever to explore the planetary body. It completed this aspect of the journey which started on January 19, 2006; a 9-year voyage. The success of its missions, however, has led NASA to lengthen its space duties, setting its trajectory to go beyond Pluto towards the Kuiper belt, a ring of asteroids and small moon-like bodies surrounding the outermost regions of the solar system. This belt is similar to the asteroid belt that exists between Mars and Jupiter, except that it is estimated to be about 20 times wider and 200 times greater in mass. The specific target of New Horizons exploration of the Kuiper belt is the body named 2014MU69, of which the spacecraft plans to explore and gather data. This aspect of the mission is expected to end on January 1, 2019. If the spacecraft continues to be operational, by 2038 it should enter the Heliosphere (the limit of space that is influenced by the Sun) right on the borders of Interstellar space, joining Voyager 1 and Voyager 2 which were the first two man-made crafts to enter interstellar space. From there, more information would be provided concerning the components of Interstellar space, including the nature of the pressure created between the Heliosphere and Interstellar space by the Plasma created by the solar winds from the sun.
These, along with various other plans, all show evidence of man’s unending obsession with exploring the stars. Mathematicians, Physicists, Jet Propulsion engineers and Astronomers the world over are continually thinking and experimenting, hypothesizing and creating, to ensure that every single idea is considered and every option is observed. The question of “how far should we go” is another issue which would incorporate the ethics of man in relation to space travel. This is especially when considering that space programs cost millions, even billions of dollars to be implemented and maintained. Also, sending rockets and probes into space unmanned is one thing, but sending humans into space is another area of exploration, as NASA is currently working on plans to send man to Mars to colonize the red planet by 2030. For now, Juno acts as a major catalyst to this entire procedure. It is now left to see how her flight over the next two and a half years would influence voyages of her kind afterward. There is much more to the dynamic of Space travel than just simple exploration. However, when it comes to the curious mind and the brightened eye, sometimes exploration might just be a good enough reason.