Comet

Mar 22 2023

Why ‘Oumuamua accelerated

Comet (?) 'Oumuamua is the first known object formed outside the solar system that astronomers could observe on its way through our solar system. Its nature is still not conclusively explained - at least for some researchers. What we do know: It has not shown any radiation. Measurements in this regard are so accurate that even a cell phone transmitting on the object would have been noticed. But 'Oumuamua also shows a small non-gravitational acceleration. So it didn't move exactly as would have been expected based on mass and velocity. This is not unusual for comets. They typically release…

2019 LD2: the unruly comet

Asteroids and comets are generally thought to be different classes of celestial objects. But is the strict distinction really justified? The interstellar visitor ʻOumuamua, for example, was initially thought to be a comet, but didn’t develop either a coma or a tail and was then classified as an asteroid. In the meantime, its trajectory has been calculated so precisely that it must have lost mass – which means it is definitely a comet. The object 2019 LD2 discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) of the University of Hawaii also appears to be some sort of hybrid.…

Dwarf planet Pluto – a gigantic comet?

Researchers from the Southwest Research Institute in the USA have put forward an exciting theory in the journal Icarus. The scientists have tried to assemble a model for the formation of the dwarf planet Pluto. Here they have looked in particular at the nitrogen-rich Sputnik Planitia basin that is covered by a gigantic glacier made from frozen nitrogen. They combined this data with results from the Rosetta probe that studied the comet 67P. Their findings: the nitrogen content fits well with the theory that Pluto is a conglomeration of approximately one billion (!) comets or other similar Kuiper Belt…