NASA’s history-making spacecraft, Juno, made a spectacularly successful journey to Jupiter this July 4, entering the planet's orbit and transmitting back to Earth all manner of data about the mysterious gas giant 370 million miles away from us. The success of the mission came after five lonely years of the solar-powered probe flying at 165,000/mph through frozen space on its journey to explore the biggest planet in our solar system.
Before suspending its instruments in order to do an engine burn descent to enter Jupiter's orbit, Juno snapped this poignant image of the planet, capturing the vast unknown:
Once on the other side of the descent, Juno powered back up.
In addition to the sensitive instruments that allow it to communicate with ground control at a 48-minute delay, Juno flies with some very important, if tiny, cargo: three Lego figurines—the Roman god Jupiter, his wife Juno and Galileo, the Italian astronomer who first discovered Jupiter’s largest four satellites, which are named for him. Presumably they had a lot to talk about in the years they spent in flight. If you want to see renderings of what they are seeing from on board, check out this tool from NASA that allows you to interact with the mission data:
Jupiter is huge—11.2 times the size of Earth and two and half times as heavy as all the other planets combined. It is made up of hydrogen and helium, but what is at its core is unknown, and what Juno is hoping to discover. A dense deposit of rocky material or heavy metals is possible, though it could also be a swirling soup of yet more gases. Jupiter has no solid surface to land on, so Juno’s 3000 mile high orbit is the closest point yet at which observations have been possible.
Jupiter's composite of helium and hydrogen, along with its high emissions of radiation has seen it referred to as a “failed star”, or brown dwarf, with the theory being that perhaps our solar system was once in our distant past a dual-star system—though that's now thought to be unlikely. Regardless, Jupiter's radiation emissions are mind-boggling, said to be as powerful as 100 million x-rays, and its magnetic fields are likewise enormously powerful; to protect Juno's instruments from them, they were encased inside impenetrable titanium.
It’s thought that Jupiter was responsible in part for ensuring the relative safety of the habitable zone Earth finds itself in. During the primordial time when the inner planets were forming, Jupiter’s gravity acted like a slingshot for asteroids, sending them to where they are now in the asteroid and Kuiper belts, at relatively safe distances away from Earth, and keeping the inner solar system statistically free of life-ruining asteroids. So thank you, giant, faraway protector.
As Juno continues to transmit its data back to us with help from its on-board Lego crew, the mission hopes to uncover more of Jupiter's secrets: how much if any water the planet contains; if its raging giant storm spot is permanent or a temporary (relative to cosmic time, having first been observed by humans in the 1600s) feature; what constitutes its atmosphere, and perhaps most crucially, how and when it formed and exactly what influence it had over the origins of Earth.
Juno is a feat not only of engineering—being now the farthest flying solar-powered probe ever sent into space—but what it could find on its journey might tell us things that so far no one knows about the beginnings of life in our solar system.
Elmo is a writer with Real Future.