Auroras – the solar system's universal light show (except Neptune... sorry, Neptune)

Scientists have found that the fundamental mechanism behind the spectacular light shows of auroras on Earth are universal throughout the solar system. Using data from space probe BepiColombo's first flyby of Mercury, the researchers have shown the processes creating auroras on the planet closest to the Sun are shared with …

[Anonymous Coward]

Magnetic field ?

Don't you need an iron core for that ?

[Lil Endian]

Re: Magnetic field ?

A magnetic field is generated (in a celestial body) by a dynamo effect. That requires an electrically conductive interior - such as an iron core.

See: https://en.wikipedia.org/wiki/Dynamo_theory

Or, for a more sciency article - https://www.sciencedirect.com/topics/earth-and-planetary-sciences/dynamo-theory

[xyz]

Re: Magnetic field ?

Just remember that the keyword in both links is... "theory".

[mtp]

Re: Magnetic field ?

The word theory does not mean what you seem to think it does.

"A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed"

[Potty Professor]

Re: Magnetic field ?

...and an atmosphere? I understood that the light show was produced by excitation of gas molecules by the incoming electron stream, so no atmosphere should mean no aurora, or am I whistling in the dark?

[Anonymous Coward]

Universal except when it isn’t ?

Neptune is a gas giant and therefore has some form of atmosphere.

It also has a magnetic field more than 20 times greater than that of earth, but compared to other planets is skewed compared to its rotational axis.

So is it just “holding it wrong” ?

[prandeamus]

Re: Universal except when it isn’t ?

The other gas giant, Uranus, is the one with a very skewed rotational axis. So I doubt that's the reason, but I'm no expert. I'm posting here because it's a Friday, not because I know very much.

[jmch]

Neptune?

"now observed at all magnetized planets, except Neptune..."

Slightly confused by the headline and this.... Is Neptune the only planet that hasn't yet been *observed* to have auroras, or is there a fundamental reason why Neptune in particular can't have auroras?

[prandeamus]

Re: Neptune?

Observed, if I understand correctly. The new discovery is that Mercury has been shown to have an aurora, and that leaves Neptune as the one where auroras have not been observed. They may be a fundamental reason (maybe the distance from Sol) but that's not certain.