In the search for the elusive planet X, astronomers have discovered 12 additional moons around Jupiter and brought the total number of known satellites to whopping 79.
The new moons are all relatively small – between 1 and 3 The researchers said, "They were first discovered in spring 2017 by researchers who spent the last few years looking for Planet X." (19659002), also known as Planet 9 – an object that you expect to be the size of a Mars or larger.
They believe that it is in the distant solar system, 100 times farther from the sun than Earth. (For reference, Pluto is about 30 times farther from the Sun than the Earth.)
Any object that receives very little light far from the sun, reflecting it back to telescopes on Earth, has the search "So challenging, "said Scott Sheppard, an astronomer at the Carnegie Institution for Science in Washington, who led the work.
To help them with this quest, the research team uses a four-meter-long telescope in Chile connected to the largest camera
It's called the Dark Energy Camera, and it's about the size of a smart car Sheppard said.
Because the camera is so big, it can take a much larger sky with a single exposure than was previously possible.
"It allows us to be much more efficient than in the past," said Sheppard. "In the past, this one image was basically the area of a full moon in the night sky, and now we can cover that twelve times."
Sheppard and his colleagues focus primarily on exploring the deep outer solar system, but a few years ago they did realized that the Jupiter system is well positioned to look more closely at its myriad satellites.
"It was a bit like trying to kill two birds with one stone," Sheppard said. "We thought we could find a few more moons by covering the entire Jupiter system in a single exposure, which did not happen before."
The researchers deliberately chose fields to see Jupiter's moons without the light that came from the planet itself.
They were able to determine which points of light in their pictures were Jupiter's moons because they moved across the sky at the same speed as their host planet.
"Anything that moves much slower would be a distant object," Sheppard said.
Their observations revealed the 1
Most of the newly discovered moons belong to two previously known satellite families.
Nine of them circle Jupiter in a wide arc, retrograde orbit, meaning they are moving in the opposite direction in which the planet is turning. It takes about two Earth years to orbit Jupiter.
Two of them are part of an inner group of moons orbiting the planet in the degree or in the same direction as it turns. This group completes a single orbit around Jupiter in one year of Earth.
However, there is one moon tentatively called Valetudo. It does not belong to any known group of moons and follows a strange prograde orbit that occasionally crosses the path of the retrograde moons.
"It's basically the wrong way to go on the highway," Sheppard said. "And that means the probability of a collision is much higher."
Sheppard said the discovery of Valetudo might help answer some lengthy questions about the emergence of the extended Jupiter system.
Scientists believe that the families of the small moons we see that orbiting Jupiter may once have been single, larger moons that broke apart after colliding with something – perhaps an asteroid or comet.
But if Valetudo is the remnant of a much larger moon with the same strange orbit, it is possible that the families of the small moons were created by the collision of two moons.
Sheppard added that the team is currently performing a supercomputer simulation to determine how long Valetudo will crash into one of the retrograde orbiting moons. He expects that it will eventually be between 100 million and 1 billion years.
"The likelihood that we will see an impact in a year is negligible, but probably in the life of the solar system," said Gareth Williams, an astronomer at the Harvard Smithsonian Center for Astrophysics, who identified the orbits of the newly discovered moons for the International Astronomical Union determined.
Williams said he was not surprised by Sheppard's discovery of additional moons around Jupiter.
"We know there are probably hundreds of moons around Jupiter that are one kilometer or more in diameter at the moment." However, he said the finding was still significant.
"I know how many satellites around each planet That's important because every formation scenario for the planet must explain the satellite system," he said. "If your model shows only 20 satellites, it will not fly if you suddenly have 60."
He added that now that these moons are discovered and their orbits are determined, the scientists know where to direct their telescopes to study them more closely. This helps them determine how dark they are and what they are made of, and helps researchers to learn more about the composition of our solar system.
In the meantime, Sheppard's hunt for Planet X continues. Who knows what else he and his colleagues might discover along the way?