3 ms·
So conversely the best candidate for a space-faring species might be from a very small planet.
by elevaet 4y ago
So conversely the best candidate for a space-faring species might be from a very small planet.
- Ekaros 4y agoProbably something between Earth and size of Mars. As getting too light makes holding atmosphere harder.
- lampshades 4y agoKind of like how the best candidates for original sea travel came from small islands.
- koheripbal 4y agoNo, because smaller planets cannot hold an O2/CO2/N2 atmosphere like ours.
- elevaet 4y agoThere must be a sweet spot size of planet that is less massive than ours, but that is still big enough to hold an atmosphere. edit: "That critical size, according to Arnscheidt and the other authors of the study, is 2.7 percent the mass of Earth. They say that any smaller than that, and the planet simply won’t be able to hold onto its atmosphere and water long enough for life to appear." shorturl.at/bdgIK So, a mercury sized planet could hold an atmosphere in theory, and require around 1/3 the velocity to escape (vs. earth)
- shagie 4y agoThe tangent to this is - the reason that Mars doesn't have much of an atmosphere isn't that its not gravitationally massive enough to hold on to it, but rather that its core cooled and lost its magnetic shielding. The lack of a magnetosphere then allowed the solar wind to strip its atmosphere. https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space https://www.nasa.gov/press-release/nasas-maven-reveals-most-...
- PeterisP 4y agoIs an atmosphere necessary? After all, our life evolved in the oceans as far as I understand, and you can have oceans without atmosphere like Europa in our solar system.