Free Republic

Of the 461 objects described for the first time in the new paper, a few stand out. Nine are known as extreme trans-Neptunian objects, which have orbits that swing out at least 150 AUs from the sun. Four of those are extremely extreme, with orbital distances of 230 AUs. At these distances, the objects are hardly affected by Neptune's gravity, but their strange orbits suggest an influence from outside the solar system. Some researchers think that influence might be a yet-undiscovered planet, dubbed Planet Nine. (Others think that the combined gravity of lots of little objects, or, alternatively, nothing more...

A comet unlike any other in recorded history is on a trajectory to zip through the inner solar system in less than a decade, but like most space rocks that make the news, it isn’t anything to lose sleep over. Comet 2014 UN271 was observed during a mission called the Dark Energy Survey back in 2014, but skywatchers didn’t realize that the data gathered was showing a comet until mid-June of this year. Pedro Bernardelli and Gary Bernstein were the two people who made this realization, giving Comet 2014 UN271 a name that rolls off the tongue a bit easier:...

Scientists briefly estimated that Comet Bernardinelli-Bernstein, as it's now known, was the largest such icy body identified to date, perhaps more than 100 miles (160 kilometers) across. Additional observations have cast that into doubt, but given the "megacomet" a new distinction: it sprouted a tail remarkably far from the sun, suggesting more revelations to come. All told, the object offers astronomers an unprecedented opportunity to watch the antics of a comet. Although what initially stood out to Bernardinelli was the comet's weird orbital characteristics, the discovery made such a splash because of a different trait, the comet's estimated size. Based...