Freethought & Rationalism Archive

MyKell · 03-01-2003, 03:16 PM

I assure you, I am not confusing Titan with Europa

Check this out:

HUBBLE FINDS OXYGEN ATMOSPHERE ON JUPITER'S MOON EUROPA

Also:

97-07-23 Galileo Finds Europa Atmosphere

Abacus · 03-01-2003, 03:22 PM

From the article:

Quote:

The atmospheric pressure is less than one hundred-billionth of that of Earth's atmosphere.

That's not much of an atmosphere.

lpetrich · 03-01-2003, 08:17 PM

There's a downside to a Europa orbiter:

Getting into orbit.

Europa's surface-orbit velocity is about 1.4 km/s, and a surface-orbit satellite would have a period of around 2 hours.

However, Europa orbits Jupiter with a speed of 14 km/s (distance: 671000 km, period: 3.55 d). And the escape velocity at Europa's distance is 20 km/s. And an incoming spacecraft will be traveling at a greater Jupiter-relative speed.

v(at r) = sqrt(v(infinity)^2 + v(escape at r)^2)

This means that a velocity change (delta-V) of at least 6 km/s will be necessary to get into orbit around Europa.

So a Europa orbiter will need a LOT of propellant in order to arrive in orbit there.

Source of parameter values.

Shake · 03-02-2003, 11:13 AM

Quote:

Originally posted by Shadowy Man
Well, it'll be back. Remember that they've been proposing a Pluto mission for ages and I think they've finally been given a real budget.

Yeah, there's a story about Pluto here with links to some additional articles relating to the exploration of Pluto.

As far as Europa, haven't you all read 2010? We're supposed to stay away!

thebeave · 03-05-2003, 02:47 PM

Do you suppose there's a chance there would be some leftover weight budget on the Pluto spacecraft? I'd like to put Jerry Falwell on if so.

enigma555 · 03-05-2003, 02:56 PM

pppph. I doubt there would be enough weight free to fit his lard-ass in... unless of course we ran him through the incinerator once or twice prior.

Who knows though. He is about 90% hot air after all...

Shadowy Man · 03-05-2003, 03:00 PM

Quote:

Originally posted by thebeave
Do you suppose there's a chance there would be some leftover weight budget on the Pluto spacecraft? I'd like to put Jerry Falwell on if so.

As pleasing as that thought might be, there's probably not even enough weight budget for what they have planned.

Valentine Pontifex · 03-05-2003, 10:03 PM

Quote:

Originally posted by Shadowy Man
As pleasing as that thought might be, there's probably not even enough weight budget for what they have planned.

And it would be just grounds for Pluto declaring war.

(Yes I do know it is just a flyby, but even so...)

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03-01-2003, 03:16 PM	#11
MyKell Regular Member Join Date: Feb 2003 Location: Amman, Jordan Posts: 258	I assure you, I am not confusing Titan with Europa Check this out: HUBBLE FINDS OXYGEN ATMOSPHERE ON JUPITER'S MOON EUROPA Also: 97-07-23 Galileo Finds Europa Atmosphere

03-01-2003, 08:17 PM	#13
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	There's a downside to a Europa orbiter: Getting into orbit. Europa's surface-orbit velocity is about 1.4 km/s, and a surface-orbit satellite would have a period of around 2 hours. However, Europa orbits Jupiter with a speed of 14 km/s (distance: 671000 km, period: 3.55 d). And the escape velocity at Europa's distance is 20 km/s. And an incoming spacecraft will be traveling at a greater Jupiter-relative speed. v(at r) = sqrt(v(infinity)^2 + v(escape at r)^2) This means that a velocity change (delta-V) of at least 6 km/s will be necessary to get into orbit around Europa. So a Europa orbiter will need a LOT of propellant in order to arrive in orbit there. Source of parameter values.

03-05-2003, 02:47 PM	#15
thebeave Veteran Member Join Date: Dec 2001 Location: Silicon Valley, CA Posts: 4,183	Do you suppose there's a chance there would be some leftover weight budget on the Pluto spacecraft? I'd like to put Jerry Falwell on if so.

03-05-2003, 02:56 PM	#16
enigma555 Regular Member Join Date: May 2002 Location: Washington, DC Posts: 282	pppph. I doubt there would be enough weight free to fit his lard-ass in... unless of course we ran him through the incinerator once or twice prior. Who knows though. He is about 90% hot air after all...

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