Tango needs two, people say. The same applies to the moons of a neighboring planet.
According to a recent study published in the journal Icarus last month, two of Neptune's tiny moons – Naiad and Thalassa – circle in an unprecedented way that scientists call "the moon". Dance of avoidance. "The study calls the two moons" partners, "noting that although they're only about 1,150 miles apart – about the distance from San Diego to Seattle – they never get close enough to touch each other.
The big picture is that moons do not like being too close to each other when orbiting a planet, "said Mark Showalter, planetary astronomer at the SETI Institute and co-author of the new paper, Stable to Salon if they're not getting too close and we've found that two moons are exceptionally long to avoid each other. "
Naiad's orbit is tilted and perfectly tuned to overtake his slower-moving partner Thalassa a distance of about 2 miles from each other. During this so-called dance of avoidance, Naiad Neptun orbits every seven hours. Thalassa lasts for seven and a half hours. According to the researchers, the orbit for an observer would look like an up and down zigzag pattern.
"We call this repetitive pattern resonant," said Marina Brozovic, solar system dynamics expert at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of the new paper, said in a media statement. "There are many different types of 'dances' that can be followed by planets, moons and asteroids, but this has never been seen before."
This particular pattern was discovered when researchers analyzed observational data from NASA's Hubble Space Telescope. The research provides the first insights of this kind into the inner workings of Neptune's inner moons.
The researchers also found that the relationship between these two moons is not only one, Showalter said, but also the number of orbits is strange. Najad orbits Neptune 73 times for every 69 rounds of Neptune through Thalassa.
Neptune has 1
"We suspect that Naiad was put into orbit by an earlier interaction with one of Neptune's other inner moons," Brozovic added. "It was only later, after the inclination of the orbit was established, that Naiad was able to settle into this unusual resonance with Thalassa."
In fact, the result for researchers was surprising and pleasant.
"For me it's always exciting to see the universe There are crazier solutions to a problem than we humans can imagine," Showalter said. "It's a crazy configuration."