This artist's conception illustrates a giant planet floating freely without a parent star. Astronomers recently uncovered evidence for such lone worlds, thought to have been booted from developing star systems. The sun may have captured such a planet, which new work shows may reside at the edge of the solar system.
In this artist's conception, Jupiter's migration through the solar system has swept asteroids out of stable orbits, sending them careening into one another. As the gas giant planets migrated, they stirred the contents of the solar system. Objects from as close to the Sun as Mercury, and as far out as Neptune, all collected in the main asteroid belt, leading to the diverse composition we see today.
15 Things You Didn’t Know About Outer Space... (Fact 5 is wrong: According to the picture, yes, Jupiter is the second largest planet, and Saturn’s density is the lightest in the entire solar system, however, the planet itself is only lighter than Jupiter and Neptune, making Saturn the 3rd heaviest planet in the solar system)
The rings of Saturn are among the crown jewels of our solar syste, but it turns out that asteroids can have rings of their own, too. Here: See an artist's view of the rings surrounding the asteroid Chariklo, which is only 155 miles (250 kilometers) across. The asteroid is the first non-planetary body in the solar system discovered to have its own ring system. Image released March 26, 2014. [See videos and read the full story here]