[mr_toad]

The host star is described as very inactive, which probably accounts for the retention of atmosphere.

[kazinator]

A really powerful magnetic field could help, also.

Without our field, we would be in trouble, too.

[jjk166]

This is false. Earth's magnetic field does not significantly impact atmospheric loss. For comparison, Venus is closer to the sun and has no magnetic field, but has a substantially thicker atmosphere than earth.

[tonmoy]

I’m not 100% sure I follow what you mean, but here is a link from NASA saying our magnetosphere protects the atmosphere from erosion https://science.nasa.gov/science-research/earth-science/eart...

[rustyhancock]

He's right the magnetosphere doesn't significantly protect our atmosphere. It probably reduces helium loss on earth and other lighter elements.

In addition to his Venus example, Mars lost its atmosphere because it's gravity was too small. Not because it lacks a magnetic field.

[eru]

Venus has lots all her lighter elements in the atmosphere. Basically no hydrogen left (not even in the form of water).

[gregdaniels421]

> Basically no hydrogen left (not even in the form of water).

There should be a decent amount left as sulfuric acid.

[eru]

Yes, confirmed. Though depends on what you mean by 'decent amount'.

[upelephants]

Atmosphere E != Atmosphere V

[PeterHolzwarth]

Pithy rejoinder, thanks! If this were /. in 1999, I'd call this +1 Insightful.