After all, humans are figuring out the finer points of a manned mission to Mars right now. Could a trip to Jupiter also be on the cards?
Unfortunately, a manned mission to the surface of Jupiter isn’t feasible and may never be. However, it isn’t because it’s too far away.
In this post, we’ll discuss the distance between Earth and Jupiter and why a trip to this giant planet is impossible.
How Far Away Is Jupiter From Earth?
The distance between Jupiter and the Earth constantly changes due to the two planets’ orbit. At their closest Jupiter is 365 million miles (588 million km) away. At its farthest, it is 601 million miles (968 million km) from Earth. That is a pretty mind-shattering distance, right? Yet, it’s still only a fraction of a light year. One light year stretches out over a whopping 5.88 trillion miles (9.46 trillion km).
How does this interplanetary distance compare to the trip from Earth to Mars? Well, Mars is only 154.17 million miles away. So it’s a roughly 5.5 times longer journey to reach Jupiter from Earth.
The distance between Earth and Jupiter makes it sound unreachable, but fortunately, that’s not always the case. As it stands, nine different spacecraft have reached Jupiter.
These crafts have all been unmanned space probes that have gathered a significant amount of information about Jupiter. This is why we know so much about this distant neighbor without ever having visited it ourselves.
How Long Would It Take To Reach Jupiter?
It took the Galileo space probe roughly 6 Earth years to reach Jupiter from Earth. It did so traveling at about 106,000 miles per hour (17,600 km/hr).
Considering that the fastest humans have ever traveled was 24,816 miles per hour (39,897 km/h) in Apollo 10. At that speed it would take over 30 years for a manned mission to reach Jupiter by Galileo’s course. That is only if Apollo 10’s top speed could be sustained for the entire trip, which wouldn’t be possible.
That said, Galileo did take a rather circuitous route, using the gravity of various celestials to catapult it towards its destination.
The Voyager 1 probe, by contrast, reached Jupiter in only 2 years. It traveled at 38,214 mph (61,500 km/h), which isn’t too far off what Apollo 10 was capable of.
And bear in mind that, at this point, Apollo 10 is an ancient vessel in technological terms. We will no doubt build faster spacecraft in the future. However, even then, a jaunt to Jupiter would be a massive undertaking.
Why Can’t We Land On Jupiter?
There are a myriad of reasons why we’ll probably never be able to get anywhere near the surface of Jupiter, besides the vast distance, of course.
No Solid Surface
Jupiter is a gas giant, meaning it’s composed of gasses rather than solids. Only the four closest planets to the sun are terrestrial in composition, meaning a significant portion of their composition is solid.
Obviously, the lack of a surface to land on is a major issue for any plans to visit the planet. Perhaps to say “lack of a surface” isn’t quite correct, as Jupiter is actually covered by the largest ocean in the solar system.
Fantastic, right? If we take some dinghies with us, we can set sail on the mighty waters of Jupiter. Alas, “water” isn’t quite correct either. With a gaseous composition similar to that of the sun, there could never be any water on Jupiter.
The ocean mentioned above is made of super-pressurized hydrogen, and guess what… liquid hydrogen is highly flammable.
Just a small amount of oxygen can trigger an incendiary chemical reaction. So oxygen-breathing animals taking a boat trip on an ocean of the stuff isn’t a good idea, even if it were possible.
Atmospheric Pressure
The surface pressure on Earth is roughly 1 bar. On Jupiter, you’d be subjected to 10 bars of pressure. Considering that the human capacity for bearing pressure is about 2.5 bar, it’s safe to assume we wouldn’t fare well on this distant planet.
At Jupiter’s core, this pressure reaches an incredible 650 million lbs. Added to the pressure the temperature is extreme. It is thought that the temperature at Jupiter’s core is 43,000 degrees Fahrenheit (24,000 degrees celsius).
No Way Of Leaving
Let’s say for the sake of argument that we could get to Jupiter; how would we return?
The atmosphere of this gas giant is 90% hydrogen, and as mentioned earlier, it’s highly explosive. This means that the usual technique of using combustion to provide thrust would be strictly out of the question.
A Trip To Jupiter’s Moons
Okay, so it’s clear that a manned mission to Jupiter isn’t possible. However, the moons of Jupiter are a different story. Both NASA and ESA are working on unmanned exploratory missions to Europa to assess the possible habitability of the icy moon.
It’s already known that this moon is host to a subsurface ocean of saltwater comprising twice as much water as there is on Earth. Future studies hope to establish the possibility of a manned mission to Europa.
NASA has proposed just such a mission, giving the 2040s as a viable launch time. The biggest hurdle we face in this undertaking is how to protect astronauts and equipment from the radiation Europa receives from Jupiter.
Lifeforms on the surface of Europa would have to find a way to weather 1800 times the dose of radiation we receive here on Earth on an annual basis.
Final Thoughts
Jupiter may not even be a single light year away from Earth, but that’s not to say it’s close by. An average of 444 million miles (715 million km) sit between our Blue Planet and the hydrogen-rich gas giant.
Yet it’s not the distance that makes it a difficult destination for us humans, but its composition and atmospheric conditions.
With no solid surface to land on, a visit is very improbable, and a return visit would be potentially impossible.
Landing on Europa, on the other hand, one of Jupiter’s moons, is a much more feasible prospect.
We will leave you with an interesting link between Jupiter and the first measurement of the speed of light. In 1676 the Danish astronomer Ole Roemer used the orbits of Jupiter’s moons to calculate the speed of light.
Hi, my name is Jason Anderson, and I am a Physics Professor. Ever since I was a kid, I’ve been fascinated with space, the universe, the moon, you name it. I spent hours and hours at the planetarium close to my hometown, wondering what else could be out in the universe.
Since then, I’ve been an avid stargazer and astronomer, and love nothing more than spending my time charting stars, observing planets, and finding constellations.
This is why I decided to start Telescope Guru. I only wish to share this fun pastime with the world. With this site, I hope to answer all of your questions relating to astronomy, telescopes, and stargazing.
