|Halley's Comet passing the Earth with the relative velocity of 70.56 km/s
Massively hypersonic, as its name suggests, is a sub-category of the term hypersonic. In scientific communities, they generally refer to anything above 25 times the speed of sound as massively hypersonic. Albeit there isn't any explicit rule about this.
As such for the sake of convenience and better organization, the OBD regards any speed value above Mach 100 (34,029 m/s) as massively hypersonic (often abbreviated to MHS).
Massively hypersonic is known for being the largest speed category (aside from massively FTL, but that's given)
It ranges between Mach 100 and Mach 8810 (2997924.6 m/s), till the beginning of sub-relativistic category.
Some real life objects and events known to be massively hypersonic:
- Speed of comets and meteors originating from outside the Solar System
- Initial detonation velocity of nuclear bombs (or the implosion velocity within the chambers of certain thermonuclear bombs)
- The propagation speed of lightning strikes (albeit the return stroke can reach relativistic speeds)
- Orbiting speed of many large astral objects like most planets orbiting the Sun or the Sun orbiting the galactic core of the Milky Way Galaxy
- Comprehensive Speed Scale
- Speed of Light
- Speed of Sound