JuMBOs

Basic Information

Jupiter-Mass Binary Objects are pairs of Rogue Jovian Planets orbiting each other outside of Star Systems. In 2023, the James Webb Space Telescope discovered 40 such pairs in the vicinity of the Orion Nebula. This is an astonishing discovery. If there are 80 such planets (40 pairs) in a relatively small region of the galaxy, it suggests that something is wrong with our accepted models of how planets form. How and why are so many planets getting sent hurtling out of their star systems and finding each other in the void?

Sources

Bibliography

1. YouTube video about James Webb discovery

2. CNN article on the James Webb discovery

3. Wikipedia on Rogue Planets

Game and Story Use

• A pair of JuMBOs hurtling through the dark of space could be an interesting place for space disaster or outer space exploration scenario.
  • While you'd expect rogue planets to be terribly frigid and lifeless, the large size and thick atmospheres of a gas giant might possibly (at least possible enough for gaming) generate heat and pressure to allow for some sort of extremophile weirdo life. See alien biology for ideas on what sort of critters might develop there.
    • In the unlikely event that there is life (or civilization) in such a "system", it's worth considering if each of the two planets has its own independent biosphere or if there's somehow an exchange or transit between the two planets.
    • A Europa style satellite would be a good option, with an ecosystem based on geothermal energy.
• Perhaps the JuMBOs are being forced out of star systems by, or in furtherance of, some sort of stellar megastructure project. They may have been "launched" by a stellar engine, or a massive stellar-scale mass driver.
  • They could be a civilization escaping a truly epic disaster. They'd need amazing technology or weird alien biology to survive without a local sun to warm them.
  • The planets might actually be projectile ammunition for a truly devastating weapon of mass destruction. It would take many years for the orbiting "rounds" to reach and destroy their target.
  • They could just be huge balls of resources being sent safely to a construction site in deep space, where an enormous megastructure is being built, such as a dyson sphere.
  • Or they might not actually be planets. What if it's the eggs of some horrifically large god of the cthulhu mythos?
  • For those pondering the consequences of that star destroying planet-gun-thing in Star Wars VII, these might be the survivors of a system which has had its primary destroyed.
• Where fuel scooping is a thing, these clusters may make interesting waystations for long range travel.