Something of more substance at https://dailygalaxy.com/2025/07/molecular-jet-detected-first-time-giant-comet-largest-ever-approaching-inner-solar-system/ … a molecular jet has been detected for the first time on a Giant Comet, one of the largest ever observed. It is approaching the inner solar system. The discovery is said to challenge mainstream thinking about the nature of comets.
It has been christened the Bernardinelli-Bernstein comet, no doubt soon to be reduced to BB. It is currently in the outer solar system but its recent activity suggests it is far more active than initially thought. Astronomers are looking at it on the ALMA radio telescope in the Atacama Desert of Chile. It revealed the comet has a nucleus of 140 km in diameter and is emitting a molecular jet that includes carbon monoxide. The stuff that comes out of the exhausts of cars. This is a long way out for such activity- it is thought. Unusual, we are told, in spite of the fact this telescope has a fairly short life span. It is currently in the vicinity of Neptune where temperatures are thought to freezing – yet the nucleus is actively releasing gases. It hasn’t dawned on the press release writer that comets may not primarily release gases as a result of heat from the sun – but for some other reason.
The comet is large, they say. What would they think about a Centaur object on the same trajectory? It is much bigger than Comet Halley, which is just 11 km across. Well, that was on its last passage through the solar system. It has been doing that every 75 or 76 years over thousands of years. Each time it rounded the sun it lost matter. How big was Halley when it first showed its face in the inner solar system, nudged by Jupiter. It may have been even bigger thatn 140 km across. We don’t know. Bernardinelli-Bernstein is due to round the sun in 2031.