[[1e-12 bar is, unless I’m out by a factor of 1000 or something, 100 nPa (nano pascals). To put that in context, the pressure of the solar wind in the region of the Earth can be around 1 nPa or more (http://www.swpc.noaa.gov/SWN/index.html). The solar wind must be nearly up to local atmospheric pressure at Mercury. That’d make for an interesting shape to the atmosphere, I’d have thought.]]

Good point! I’d love to see a simulation — if they did it in color and 3D it would make for an interesting BA article photo…

1e-12 bar is, unless I’m out by a factor of 1000 or something, 100 nPa (nano pascals). To put that in context, the pressure of the solar wind in the region of the Earth can be around 1 nPa or more (http://www.swpc.noaa.gov/SWN/index.html). The solar wind must be nearly up to local atmospheric pressure at Mercury. That’d make for an interesting shape to the atmosphere, I’d have thought.

As a similar experiment I tried typing the value using Unicode superscript characters but got a database error: “WordPress database error: [Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '=']“. Pathetic.

As a similar experiment, here’s a form using Unicode superscript characters: 10?¹². Let’s see how that comes out.

[[BPL: 10-12 bar is not tenuous. Earth’s surface atmospheric pressure is about 1 bar. Even 10-12 millibar is denser than Mars’ atmosphere which about 7 millibar. Guessing wildly, do you mean pascals?]]

Typo on my part. I meant to write 10 to the -12th power bars. Either I got the superscript tags wrong, or forgot them altogether, or this site won’t show them.

I’ll try down here:

10-12