I shouldn’t have edited my comment, originally it did have the requisite quotation marks.

Saturn is 95 times as massive as Earth, guess how strong its surface gravity is?

Hang on a sec! Saturn & *surface* – do those words really go together!?

Saturn is clouds – and then supercritical fluid – all the way down. So what level then is the Saturnian “surface?”

Uh, THIS much?

10.44 m/s²[5][8]
1.065 g

Gary 7

Wikipedia :

http://en.wikipedia.org/wiki/Naboo

Naboo is described as having a porous, plasma-rich interior without a molten core—a rare phenomenon among the planets in the Star Wars universe. The surface of Naboo is covered by dense swamps, rolling grass plains, and verdant hills. … Underneath the planet’s surface is a tremendous maze of passages and caves, home to immense aquatic animals and creatures that are never seen on the surface. Gungans dominate these ‘underwaterways’, using them as a highway of sorts between their surface Holy Places and their underwater cities. One gungan civilization was known as Otoh Gunga, where Jar-Jar leads Obi-Wan Kenobi and Qui-Gon Jinn.

As for :

“If I understand correctly, it’s entirely possible for a planet with a smaller radius then the earth to have the same surface gravity, assuming that planet is denser then the Earth.

Agreed – and also vice versa a larger more porous planet may well have the same surface gravity of Earth even though its radius is larger.

I did see an article somewhere earlier this year on planet types with a good chart /diagram of this concept with worlds ranging from low density high radius Ocean world types to high density Iron Cannon Ball ones – but, unfortunately, I forget which magazine that was & can’t find it right now.

Naboo might be just big enough – in radius and more importantly in mass – to do all those things. [Hold a denser atmosphere, have a planetary magnetic field, have plate tectonics, etc ..]

Mars BTW. has a mass of 0.1077* earth mass [usually symbolised as mE, I think, with mJ being mass of Jupiter /Jovian mass & m-circle with a central dot being solar mass] …

Sorry folks, one day I’ll surprise everyone (incl. myself) and get things right first time.

I’m amazed that it can be more massive than Earth and yet having the same surface gravity. When I watched SW Episode One, I was outraged at that expression “A small planet named Naboo”. I thought that if that planet was really small, then gravity would have to be impossibly weaker. Now I see that the other SW planets may have been bigger, less massive and yet habitable. …

Well “small” is a relative term.

Earth is very small relative to Jupiter but very large compared to Pluto.
Pluto in turn is small relative to Earth but is large relative to Sedna, Ceres and Vesta.

So it all depends.

If we’re talking habitable planets then Mars is just a bit too small – too lacking in mass to hold onto its atmosphere, keep its intenal dynamo going to create a planetary magnetic field and to have plate tectonics and lithographic (geological) cycle.

Naboo you might think is just big – in radius and more importantly massive -enough too all those things.

In the text ‘Planets for Man’ by Stephen Dole & Isaac Asimov (New York, Random House, 1964.) based on a Rand study and dedictaed to assessing the nature and probabilities of habitable planets it was suggested that the range of masses for a habitable planet extends from 2.35 times the earth’s mass at the large end down to 0.40 at the small end. In other words the least massive habitable planet they suggest will be just under half Earth’s mass.

Perhaps that’s about where Naboo is.

Mars Btw. has a mass of 0.1077* and yet was possibly habitable early on in its astronomical history and may one day be again if we ever successfully terraform it.

Or, as 39. QuietDesperation suggests, it could be that the use of ‘small’ there is referring to Naboo’s population, political significance and economic size.

——

* Source : Page 95-96 (foldout) Dole, Stephen, & Asimov, Isaac, ‘Planets for Man’ New York, Random House, 1964.

LOL … from this point on I hear the voice of Billy Mays reading your report.

One thing I notice is that you are very skeptical about the haze possibility and I did not get that angle from the mainstream press reports.

Thanks!

I look forward to your next book: Steam Punk Planets In The Sky.

Er… I don’t think that word means what you think it does.

*This* is steampunk:

I was outraged at that expression “A small planet named Naboo”.

I’ve purged much of that film from my mind, but I thought they meant “small” as in “unimportant.”

It’s POSSIBLE, if the surface pressure is high enough, for there to be liquid water at that temp and possibly life, if its DNA double helix is joined at the ends.

Only 42 light years? An easy trip, at 10 % light speed, we’d know for sure in only (420 years to travel, plus 42 years for return EM communication)= 462 years to know if anyone is home.

ET is SOoo hot,,,

,,,but I wouldn’t want to shake hands,,,er,,,appendages.

Gary 7

When I watched SW Episode One, I was outraged at that expression “A small planet named Naboo”. I thought that if that planet was really small, then gravity would have to be impossibly weaker. Now I see that the other SW planets may have been bigger, less massive and yet habitable.

Too bad it isn’t the only outrageous thing about that movie.

we’ve actually photographed exoplanets around Fomalhaut and HR 8799 or “Gadolabove” and 2M1207b 2M1207A.

To clarify here, 2M1207b is actually the planet itself that was directly imaged NOT the sun it was orbiting. That brown dwarf “star” in question being “named” – if you can call it that – as 2MASS J12073346-3932539 or, as its more often mercifully abbrievated to, 2M1207A.

See :

http://blogs.discovermagazine.com/badastronomy/2005/04/29/first-exoplanet-imaged/

Among other sources, incl. Wikipedia natch, for more.

BTW. Yegods, I wish they’d give these remarkable stars and exoplanets some *proper* pronouncable more easily communicable & more evocative names rather than such awkward, uninspired, hard to memorise catalogue designations! I know there’s too many new-found worlds to give *all* the exoplanets proper names but the more significant ones surely could be given reasonable monikers. I do think doing so would help with better communicating and sharing these exoplanetary discoveries to the wider community.

Also see :

http://blogs.discovermagazine.com/badastronomy/2008/11/13/huge-exoplanet-news-items-pictures/

For images of the Fomalhaut and “Gadolabovese” exoplanets.

Additionally, also check out :

http://blogs.discovermagazine.com/badastronomy/2008/11/21/another-exoplanet-imaged/

for another example of directly imaged exoplanets this time around Beta Pictoris, another Sirian A type star

From my comment #29 (back when I was posting as StevoR) there :

By my count we have no less than 7 exoplanets or candidate exoplanets imaged so far :

1. Fomalhaut b 2008 Nov 18th brightest star & just 25 ly away, type A3 V.

2. Beta Pictoris b 2008 Nov. bright & near, type A6 V Sirian, 63 ly off.

3. HR 8799 b,c & d Nov.2008 Distant Sirian star with protoplanetary disk containing planets at 25,40 & 70 AU.

4. 1 RSX J160929.1-210524 K7 orange dwarf Sept 15th 8x Mass Jove 11 x Neptune’s distance. (330 AU?)

5.2M 1207b or in full 2 MASSW J1207334-393254 imaged April 27th 2004 around a brown dwarf, a 5 Jupiter-mass exoplanet or perhaps brown dwarf this planet orbits 55 AU from its brown dwarf sun.

6.GQ Lupi b 2004ish (?) Probable brown dwarf 1-42 mJ @100 AU

7. AB Pictoris b 2003 March (earliest but probable brown dwarf) 250 AU out.

Now, okay, several of them may end up being classified as brown dwarfs and those in protoplanetary disks suffer from perhaps being technically ineligiable because of the idiocy of the IAU’s anti-Pluto “clearance” balony criterion but still ..

Which was the count as of Nov. 2008.

Since then, hmm.. right now I can’t think of any immediate additions to that list but there might perhaps have been one or two I missed, I guess. Plus we may have clarified the status of some of the boarderline brown dwarf / exoplanet one’s although, again, I’m unaware if this has happened or not. If I remember rightly, there has, sadly, also been some doubt cast over the planetary status of some of these too.

See :

http://stars.astro.illinois.edu/sow/hr8799.html

***

CORRECTION from comment # ^ 33 :

the isea idea of a super-heated water planet

is what I thought I’d written. Gah. Typos. Sorry.

In essence, GJ1214b is most probably like Venus’es super-sized, bigger and even uglier – or at least more extreme – Bad Sister! With maybe a bit of Neptune’s lower layers thrown in.

I wonder if GJ 1214bs atmosphere is steaming away behind like a comet just like with the Hot Jupiter Osiris (HD 209458 b) or not?

For Osiris see :

http://en.wikipedia.org/wiki/Osiris_(planet)

& see :

http://en.wikipedia.org/wiki/Extrasolar_planet#Detection_methods

For further info. on exoplanetary detection methods.

I wonder if there is a habitable spot somewhere on the back side… It would obviously not have breathable air, but I wonder if there’s a place where the temperature and pressure would support earth life. It might have to be far up into the atmosphere. The mountain in Niven’s Gift From Earth comes to mind.

&

@17. -jeffB :

So, can we assume this thing is tidally locked, and start talking about a Weinbaum Venus scenario with giant ice mountains, lit only by a murky twilight and incessant lightning, just beyond the terminator on the Dark Side?

Nice thought but, alas, I doubt it.

I think (28.) andy’s suggestion of a Hot Mini-Neptune and the isea of a super-heated water planet – a world covered with an immense ocean – is the most likely scenario for what GJ 1214b is like.

My guess as to what’s most plausible is that there’s most likely a thick superheated atmosphere becoming a supercritical (hot fluid /”hot ice”) atmosphere down to a magma rock surface. At no point in this model could human or biological life survive and there really isn’t a particularly solid surface anywhere.

Temperatures and pressures would be excessive even for Venus, chemical composition unknown probably toxic. Also the atmosphere could well be spreading the heat around analogous to Venus meaning there may be no cool or cold zone even if the planet is tidally locked which isn’t certain. (Mercury and Venus after all aren’t tidally locked in our system.)

So imagine you take Venus, drag it right next to the Sun, increase its mass, add a layer of steam and a supercritical superhot fluid ocean and that’s what I think we’ve most likely got in GJ 1214b. Not really a nice place to visit or a plausible habitat for anything remotely like our type of life – although fascinating in its own right.

@24. Eugene Says:

Hey, so I have a question – what do we do about stars that are angled relative to us in such a way that their planets will never transit their star? Are we stuck not knowing whether or not they have planets, or are there other ways?

Good question – yes there are indeed other ways including direct imaging – we’ve actually photographed exoplanets around Fomalhaut and HR 8799 or “Gadolabove”* and 2M1207b plus a few others which are unconfirmed candidiates planets or brown dwarfs. There’s also astrometry – looking for the “wobble” in the stars path produced by the tug of the exoplanets gravity and micro-lensing where a distant star-planet causes a change in brightness of another star. So there’s a range of exoplanet finding techniques with varying strengths and weaknesses.

And this new result serves as a brilliant reminder: we live in an age where we can taste the air of alien planets from trillions of kilometers away!

Ouch! Tasting exoplanetary air at 200 degrees Celcius? We’ve just badly burnt our tongues!

I can think of no better paean to science.

Agreed. This is a superluminous (beyond merely brilliant) piece of astronomy & news.