admin
The planet Jupiter has at least 80 natural satellites that we know of. The largest four Io, Europa, Ganymede, and Callisto were observed by Galileo di Vincenzo Bonaiuti de’ Galilei in 1609-1612, we’ve been observing them almost constantly for over four hundred years. But the four Galilean moons as we call them and their 76 sisters are still startling us today with technology allowing observations and conclusions that the immortalized Florentine father of astronomy could ever imagine. Check out these six shocking facts about Jupiter’s moons that you probably never knew!
The Moons Of Jupiter Are Likely The Key To Human Space Exploration… But They’re Crazy.
1. Europa Is The ‘Most Likely’ Place We’ll Find Life In Our Solar System
Europa is the smallest of the four Galilean moons, but we’ve been able to make amazing observations of it through Earth-Based telescopes, the Hubble Space Telescope, Pioneers 10 & 11 in 1973-74, the Galileo probe in 1995-2003, and New Horizons as recently in 2007. The findings shook astronomy to its core:
- Europa probably has liquid water. This is likely, a subsurface ocean beneath a thick sheet of ice kept warm by tidal heating from Jupiter’s immense gravity and/or volcanic activity. It is in this dark, unknown sea that life likely exists.
- There’s an atmosphere and it’s mostly Oxygen and Water Vapor! Granted, you definitely couldn’t breathe it because Europa is just too small for its gravity to hold onto a thick atmosphere. (It’s only 0.1 μPa, or 10−12 atmospheres). But it’s definitely there, which means a manned mission could harvest all the oxygen they’ll ever need.
In 2014, the US House of Representatives allocated $80 million for further studies of Europa.
2. The Galilean Moons Massive Size Could Be Saturn’s Fault
Scientists have puzzled for decades over how the four largest moons of Jupiter became so utterly massive that they are nearly planets in their own right existing in a kind of nested solar system within the greater one orbiting our Sun. But thanks to a 2018 study in Europe, astronomers might have an explanation. Sky And Telescope wrote,
“One of the astronomers who investigated this impasse is Thomas Ronnet (Astrophysical Laboratory of Marseille,France). He realized that Jupiter’s massive neighbor Saturn might be involved. When the planets were forming, their orbits were still migrating — resulting in a solar system that looked very different from the one we see now, Saturn in particular is thought to have been in an orbit much closer to that of Jupiter. So Saturn could have dispersed pebbles that were stuck in the midplane of the circumsolar disk, allowing Jupiter to capture them.”
3. Ganymede Is Larger Than Mercury!
Nope, seriously the 7th moon of Jupiter is larger than the 1st planet. In fact, it’s plain and simply the largest moon in the entire Solar System. Ganymede is 26% larger than Mercury by volume, but it’s far less dense and absolutely dwarfs Earth’s moon (aka Luna). Dr. Curt Niebur, lead scientist for Outer Planet Science in NASA’s Planetary Science Division, told Newsweek, “Moons are common in the solar system,” he said. “There’s hundreds of them. But large moons are not that common. And by large moons I mean, moons the size of Earth’s moon and larger.
“I mean Ganymede is bigger than the planet Mercury. Ganymede is only called a moon because it orbits Jupiter. If it weren’t orbiting Jupiter, it would be a planet.
“And Europa is the size of Earth’s moon. So the question really is, why does Jupiter have so many big moons?
“And we’re not sure what the answer to that is? A big part of the answer is probably very simple. Jupiter is the biggest planet by far, it pulled in a lot of stuff.”
4. Io Is The Most Volcanically Active Object In Our System
To say that Io’s volcanoes are RIDICULOUSLY over-powered (or ‘OP’ for the cool kids) is a bit of a massive understatement. Io’s volcanic eruptions are so powerful that they leave what’s known as a “plasma torus” of sulfur and ejecta trailing behind it as it orbits Jupiter. That makes it a moon WITH A TAIL for all intents and purposes! Io’s volcanic eruptions are more powerful than any found on present day Earth.
Dr. Michelle Thomsen, PSI senior scientist, described just how powerful. She told Newsweek:
“The gas from Io’s volcanoes is the dominant source of plasma (ionized gas) that fills Jupiter’s magnetosphere, which extends many millions of km away from Jupiter on the dayside and possibly to Saturn’s orbit on the nightside .”
5. Ganymede Could Protect Future Colonists From Radiation
Whenever we talk about human exploration and colonization of the Solar system, Jupiter’s moons always come up and it’s pretty obvious why. Europa has confirmed liquid water and oxygen, Callisto might also. Io probably holds mineral wealth we can’t even imagine. But there’s a problem… Jupiter to put it bluntly: is radioactive as hell!
“Jupiter is by far the most severe radiation environment of any body in the solar system, other than the Sun,” Kevin Rudolph, an engineer at Lockheed Martin who helped design and build the Juno spacecraft told PopSci
Check out the chart below and know that according to the Nuclear Regulatory Commission 4-5 Sv (sievert) will kill 50% of people in 30 days, the baseline for what they consider a “Lethal Dose” or (LD).
Engineers designing future missions to Europa are taking this extreme radiation into account. But why is the radiation on Ganymede so low? Check this out: Ganymede is so massive that like the Earth it has its own protective magnetic field!
So if we’re going to colonize Jupiter’s moons someday, this is probably where it’s going to happen. Sure, Europa has water and oxygen but unless you’re wearing some serious shielding Jupiter’s radiation will roast you alive. On Io, if the volcanoes don’t kill you, getting effectively baked by the gas giant you’re orbiting will with six times a lethal dose of radiation! Ganymede is starting to look pretty good compared to her sisters.
One Comment