Our moon may someday become a small planet, say researchers — a 'ploonet'

She may not be ours forever.

Our moon may someday become a small planet, say researchers — a 'ploonet'
Photo credit: Tom White / Getty Images
  • A new study suggests that the moons of gas-giant exoplanets may break away into their own orbits, called "ploonets."
  • Planet + moon = ploonet.
  • As the gas giants move inward toward their suns, the orbits of their moons are often disrupted, according to new computer models.

While exoplanets appear to be plentiful outside our solar system, the moons that we might expect to be orbiting them are another story. Indeed, last spring it looked like astronomers had finally found one — it was dubbed Neptmoon because of its great size — but that finding now appears less certain.

In light of this quandary, a new paper, published on June 27, looks at what might be happening to "exomoons" that orbit large gas-giant planets migrating inward toward their stars, such as our own Jupiter seems to have done.

The researchers — astrophysicist Mario Sucerquia and colleagues — hypothesize that these satellites break free of their tidal connection to their "parent" planets as they move nearer to their sun. The paper suggests that, at this point, they're not quite moons anymore — or planets — but "ploonets."

What's more, our own moon, the researchers say, may meet a similar fate one day, even though Earth isn't a gas giant. Warns Sucerquia:

"Earth's tidal strength is gradually pushing the moon away from us at a rate of about 3 centimeters a year. Therefore, the moon is indeed a potential ploonet once it reaches an unstable orbit."

Image source: JPL/BigThink

The research in the new paper is grounded on the manner in which large gas giants have been observed to slowly move inward through their solar systems toward their respective suns. It suggests that, as such a body draws close to the star, its moon's orbit — affected at that juncture by both the gravitational pull of the planet and the host star — experiences an increase in energy, which becomes unstable. This, eventually, releases the moon from the gravitational bonds of its parent parent.

Further, the paper's conclusions are based on a series of computer simulations that researchers conducted regarding what would happen to a moon orbiting a migrating gas giant. What was discovered?

The models found that 44 percent of the moons would meet their demise by being pulled into their planets (this could explain some of the planetary rings that have been observed). The system's star would seize and destroy another 6 percent. Significant amount of exomoons, however, — about 48 percent of them — would split off from their planets and begin orbiting their star as "ploonets." Around 2 percent would be blown out of their solar system altogether.

This would certainly explain why we haven't definitively found any evidence of exomoons yet.

A brief history of human dignity

What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.

Credit: Benjavisa Ruangvaree / AdobeStock
Sponsored by the Institute for Humane Studies
  • Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
  • That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
  • We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
Keep reading Show less

Astrophysicists: Gamma-ray jets exceed the speed of light

Scientists find that bursts of gamma rays may exceed the speed of light and cause time-reversibility.

An artist's drawing of a particle jet emanating from a black hole at the center of a blazar.

Credit: DESY, Science Communication Lab (used with permission by Astronomy Picture of the Day, which is co-managed by Robert Nemiroff at Michigan Tech).
Surprising Science
  • Astrophysicists propose that gamma-ray bursts may exceed the speed of light.
  • The superluminal jets may also be responsible for time-reversibility.
  • The finding doesn't go against Einstein's theory because this effect happens in the jet medium not a vacuum.
Keep reading Show less

​'The time is now' for cryptocurrencies, PayPal CEO says

Is Bitcoin akin to 'digital gold'?

Technology & Innovation
  • In October, PayPal announced that it would begin allowing users to buy, sell, and hold cryptocurrencies.
  • Other major fintech companies—Square, Fidelity, SoFi—have also recently begun investing heavily in cryptocurrencies.
  • While prices are volatile, many investors believe cryptocurrencies are a relatively safe bet because blockchain technology will prove itself over the long term.
Keep reading Show less

"Clean meat" approved for sale in Singapore

Singapore has approved the sale of a lab-grown meat product in an effort to secure its food supplies against disease and climate change.

Credit: Adobe Stock / Big Think
Politics & Current Affairs
  • Singapore has become the first country to approve the sale of a lab-grown meat product.
  • Eat Just, the company behind the product, will have a small-scale commercial launch of its chicken bites.
  • So-called "clean meats" may reduce our reliance on livestock farming, which kills billions of animals worldwide every year.
  • Keep reading Show less
    Scroll down to load more…
    Quantcast