"StarDate: Mysteries of Venus" (BBC2 20060412 Wed.)

It's on now. Is anyone else watching it?

A but dumbed-down of course, but at least it's not a repeat!

I keep hearing and reading people saying that Venus "ought to have" developed
to be similar to Earth, but its CO2 atmosphere and the greenhouse effect
caused its extreme high temperature.

Venus is significantly nearer the Sun than Earth. If Venus had had a similar
atmosphere to Earth at the start, how much hotter would it have been?

The answer to that may not be simple, I realise. Life started on Earth, cos
it was cool enough for that, which removed a lot of the original CO2 from
the atmosphere, removing a lot of the greenhouse effect. Venus, being too
hot, never got life, so could never lose its greenhouse gases.

Maybe I should be asking a different question: If Venus now, and for the next
few million years, had a similar atmosphere to that of earth now, then how
hot would it end up compared to Earth?


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.livejournal.com/userinfo.bml?user=fleetie

Fleetie wrote:
It's on now. Is anyone else watching it?

A but dumbed-down of course, but at least it's not a repeat!

a BIT ??

Yeah, I spose so.....

On Wed, 12 Apr 2006 19:22:41 +0100, Fleetie wrote:

It's on now. Is anyone else watching it?

A but dumbed-down of course, but at least it's not a repeat!

I keep hearing and reading people saying that Venus "ought to have" developed
to be similar to Earth, but its CO2 atmosphere and the greenhouse effect
caused its extreme high temperature.

Venus is significantly nearer the Sun than Earth. If Venus had had a similar
atmosphere to Earth at the start, how much hotter would it have been?

The answer to that may not be simple, I realise. Life started on Earth, cos
it was cool enough for that, which removed a lot of the original CO2 from
the atmosphere, removing a lot of the greenhouse effect. Venus, being too
hot, never got life, so could never lose its greenhouse gases.

Maybe I should be asking a different question: If Venus now, and for the next
few million years, had a similar atmosphere to that of earth now, then how
hot would it end up compared to Earth?


Martin



A bit dumbed down? Waste of time watching it.
Phil

Wasn't it Fleetie who wrote:

Venus is significantly nearer the Sun than Earth. If Venus had had a similar
atmosphere to Earth at the start, how much hotter would it have been?

There's a pile of formulae that you can use to make such an estimate
he

http://www.dangermouse.net/gurps/science/temps.html

It's somewhat simplified because that page is actually intended for
generating fictional planets for the GURPS game rather than serious
scientific enquiry, but I believe the formulae are basically sound.

--
Mike Williams
Gentleman of Leisure