what if Earth and Mars switched places?

THE 12 MOONS OF JUPITER DISCOVERED!!

12 new moons were discovered orbiting Jupiter, bringing its total count of

moons up to 79. The moons were discovered accidentally. A team led by Scott S

Shepard of the Carnegie Institute for Science were using the Dark Energy

Camera, a 520-megapixel camera mounted to the prime focus of the 4-meter Blanco

Telescope in Chile. They weren't looking for moons around planets so much as they

we’re looking for a new planet in our solar system. Jupiter just happened to be

close to their camera's field of view and sure enough, they happened to detect some

objects that were moving over time. However, those objects were not moving

around the Sun. Instead they were moving around Jupiter. The moons were discovered

in 2017, but they take between one and three years to make one orbit around

Jupiter, so it took a full year before they could confirm the orbits and verify

that these were in fact moons of Jupiter and not some background objects. Two of

the moons orbit relatively close to Jupiter. They follow what are called

pro-grade motions. That means that they orbit the planet in the same direction

as Jupiter spins on its axis. The rest of the moons orbit much farther away from

the planet in a retrograde, or backward motion. And then there's Valet to do, a

real oddball of a moon because it orbits in the same region as the retrograde

moons, but follows a pro-grade orbit around Jupiter. This is like driving your

car at high speed down the opposite lane on a highway; not exactly a particularly

stable situation. Valet todo is named after the Roman goddess of hygiene and

cleanliness and is the great-granddaughter of the Roman god

Jupiter. But no matter how clean Valet todo keeps herself, she's probably not

long for this world, at least not in the grand scheme of things. A million or a

hundred years from now, Valet todo will almost

certainly, crash into one of those moons and disintegrate. The outer moons most

likely formed as a result of collisions between once larger bodies that smashed

into existing moons around Jupiter long ago.

Valet udo may be the very last of these once larger objects. These moons are

really tiny, only about one to three kilometers across.

but Valet udo and the nine retrograde moons that were discovered with it tell

us something significant about when they formed. You see, when the solar system was

really young, it was filled with gas and dust everywhere. Had these moons been

orbiting Jupiter in those days, they would have been moving against this dust.

The dust would have caused drag forces on the moons and the moons would have

spiraled in much closer to Jupiter. So, the fact that they are where they are

today even at this tiny size tells us that they must have formed after the

solar system's dust dissipated. So, there you go! Jupiter has 79 moons - more than

any other planet in our solar system by a long shot.

Although I would not be surprised if we discovered yet more moons surrounding

Jupiter and indeed around other planets in our solar system as well. It just goes to

show that there's always something new to discover, even in our neck of the

universe. Now if you'd like to learn more about how our solar system formed, I have

 articles on that. I also have articles on moons of our solar system and on the

giant planets themselves so feel free to check them out.