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There's no definitional difference between "outer space" and just space. They're synonymous, and most commonly defined to begin at 100 km altitude. If there's
by vikingerik 4y ago
There's no definitional difference between "outer space" and just space. They're synonymous, and most commonly defined to begin at 100 km altitude. If there's any difference, it's that outer space refers to the physical region, as opposed to "space" that might refer to the mathematical and relativistic concept.
"Deep space" is another definition, which commonly means beyond lunar altitude.
Other regions of space typically use a specific descriptor - interplanetary, trans-Jovian, trans-Neptune, interstellar, extra-galactic.
- philsnow 4y ago> defined to begin at 100 km altitude I guess this is probably on Earth, which makes me wonder how far up from Earth's moon do you have to go to be "in space"?
- pfdietz 4y agoThe 100 km comes from the "von Karmen line", the altitude at which the speed you'd need to be flying to generate enough lift to stay level would equal the orbital velocity. For the moon, there is no such altitude, so space comes right down to the surface.
- philsnow 4y agoFascinating, thanks! I'm not sure I would have made the connection between lift and orbital velocity.
- vikingerik 4y agoIt's also defined for Mars (80 km) and Venus (250 km), with the same definition of where winged flight is possible based on atmospheric density and local gravity. For an airless body, there's no real meaning to the definition, the surface is pretty much equivalent to space.
- dylan604 4y agoWinged flight is not possible in LEO but yet Starlink satellites are definitely affected by the earth's atmo