Did Earth ever have methane lakes in its infancy?

Factual Questions
1

Did Earth ever have methane lakes in its infancy? I’ve read how similar Titan is to the early years on Earth.

2

No, methane requires very cold temperatures to exist in liquid form. The average temperature on Titan is around -290F. Earth has never been anywhere close to that cold, and in fact through most of its history has been warmer than today.

The major similarities between Titan and Earth is the presence of a thick nitrogen-based atmosphere and the presence of the equivalent of Earth’s hydrological cycle – rain, rivers, lakes, and transport of the vapour through its atmosphere. Except that instead of water, on super-cold Titan the “hydrology” takes the form of liquid methane and its vapour.

3

Thanks wolfup but I’m still confused about Titan’s atmospheric pressure of 146.7 kpa (1.5 millibars) and what minimum atmospheric pressure is required to keep methane in a liquid state. Earth’s atmosphere is 101.325 kPa or 1.01325 millibars.

4

That’s partially because you’ve slipped a unit - Earth’s (mean, sea-level) atmospheric pressure is 1.01325 bars not millibars.
(1 bar - same root as “barometer” - originally meant literally 1 atmosphere pressure but it’s been standardised as 100kPa. 1 millibar is 1/1000 bar or 0.1 kPa or 100 Pa)

Titan’s atmospheric pressure is about 50% higher than Earth’s and since lower pressure reduces the boiling point of liquids, Earth would have to be colder than Titan to get methane lakes.
Even with out that, above its critical point (190K or -82.6C), it’s not possible to liquify methane with any amount of pressure, and I don’t think Earth has ever been that cold.

5

Thanks Merrick for that clarification.

6

The supposed similarity of Titan to a primordial Earth is partially a remnant of a now-discarded theory that Earth once had a reducing atmosphere of (gaseous) methane, ammonia and water/water vapor. This was the presumption of the famous Miller-Urey experiment.

7

Rivers, lakes and seas would seem to imply topography that’s at least recognisable compared to earth. How similar is the topography? If the methane was replaced with water, would it superficially look the same as earth in the terrain sense?