SPACE
Most astronomers agree that there are only four terrestrial, or rocky planets in our Solar System, all of which lie close to the Sun. But new research suggests that up to five more may be lurking at the outer bounds of the Solar System. Free-floating planets are planet-sized objects that don’t orbit a star. Also called rogue planets, free-floating planets either form from clumps of gas unconnected to any star or arise around stars but get flung out of their original orbits. The James Webb Space Telescope has identified hundreds of rogue planets in the Milky Way and beyond, including waltzing pairs of Jupiter-sized planets in the belly of the constellation of Orion.Simulations show that most free-floating planets are probably as big as Mars.
While some rogue planets are ejected by their stars, stars could also reel in these lonely wanderers with their gravity, making the planets permanent orbiting members of a solar system. In a recent study, researchers propose that our own Sun, in its infancy, may have lured rocky free-floating planets too. To determine the likelihood of this, researchers used several previously developed models, or sets of equations, built on observations of free-floating planets. Assuming that our infant star had a 1-in-50 chance of trapping a rogue planet, researchers conducted 100 million simulations, tweaking factors like orbit shape to determine how many rocky worlds the Sun may have captured. The researchers also assumed the Sun’s birth environment was pretty cramped to estimate the number in the worst-case scenario, as under such circumstances “planetary capture is more difficult,” said Amir Siraj, a doctoral candidate in astrophysics at Princeton University.
The study found that two planets with a Mars-like mass, or three to five with a mass similar to Mercury’s, may dwell roughly 1,400 astronomical units (AU) from the Sun – one AU being the distance between Earth and the Sun. That would place the tr
