Solar system may be one of a kind

Reuters ^ | Thursday, August 5, 2004

[presidio9]

Our solar system may be unique after all, despite the discovery of at least 120 other systems with planets, astronomers said on Wednesday.

All the other solar systems that have been found have big, gassy planets circling too close to their stars to allow them to be anything like Earth or its fellow planets, the British and U.S.-based researchers said.

If that is the case, Earth-like planets will be very rare, the astronomers write in the latest issue of the Monthly Notices of the Royal Astronomical Society.

"Maybe these other extrasolar systems ... contain only the giant planets," said Mario Livio of the Space Telescope Science Institute in Baltimore.

Livio and colleagues took a close look at what is known about the other planetary systems that have been discovered.

[steve-b]

Livio and colleagues took a close look at what is known about the other planetary systems that have been discovered.

Detectability is in direct proportion to the size/mass of a planet (size for the eclipse method, mass for the wobble method) and in inverse proportion to the planet's orbital period (the longer each orbit takes, the longer you have to watch to detect the eclipses and wobbles). This obviously produces a severe selection effect in the currently available data.

Failure to understand such elementary points is par for the course for the media, but, really, Livio ought to know better.

[presidio9]

Sounds about right.

[Jack Black]

Juptier's moons are much smaller than Earth. The largest ones have a diameter around 1/8 that of Earth, meaning they are 1/512 the size of Earth.

I love people who know these formulas off the top of their head. Size in the above example = volume? Unless the planet is hollow the most interesting measure is surface area. What is the surface area of a planet 1/8 the diameter of earth? This tells us how much space their is to ranch, mine and ride ATVs on!! Earth = 1 Earth Surface Area. How big is Mars? Please show your work so I can learn the formulas. Thanks.

[HenryLeeII]

Solar system may be one of a kind

I'll keep an eye out for another one, but I don't recall seeing any others... ;>)

[VOA]

Livio and colleagues took a close look at what is known about the other planetary systems
that have been discovered.

Hmmm...
it will be interesting to see how "open-minded" the retorts to "Livio and colleagues" are...

[SerialRants]

When did I claim I was 'witty'? I login to freerepublic and typically look for conservative rants about politics and current events. I came across yours, shrugged, and felt like being random and left a stupid comment. Nothing more, nothing less. You then take that comment and make broad implications from it. Ok, people have now 'accepted' your posting and it is very popular. Bravo! I rescind my comment about it being 'uninteresting' to the average freeper. Happy now? As far as caring about getting a 'better feel for what passes for etiquette here', give me a break. I don't live my life to gain a acceptance from forums. I could just as easily changed my name, made a comment like, "Great find! blah blah blah" and you'd be kissing my ass right now. I speak out and call your topic lame, you call me lame, oh well. If you start a hot topic that sparks interest I'll give props, but I'm sorry Presidio, I just wasn't feeling this post. Perhaps your 'fantastic sense of humor' can accommodate that. After all, what is a community of conservatives good for if we can't 'bust each other's ball's' once in a while.

[Jack Black]

In an infinite universe there are infinite possibilities.

But is the universe infinite? Isn't the current thinking that it is finite. Very big but finite (except for the time dimension).

So there are 10^google possibilities, but not infinite.

[Taffini]

bumpppett

[Hermann the Cherusker]

I believe surface area is 4/3 * PI * radius cubed. I hope I'm not confusing formulas here.

[Hermann the Cherusker]

Sorry, I am confusing them.

Spherical Volume is 4/3 * PI * radius cubed

Spherical Surface is 4 * PI * radius squared

Diameter of:
Io - 1942 miles
Europa - 2000 miles
Ganymede - 3400 miles
Callisto - 3000 miles

Earth - 7926 miles

The Jovian moons are bigger than I recalled. The Earth has 5 times the surface of Ganymede, the largest, and 13 times the volume.

[<1/1,000,000th%]

Since we can't currently see other solar systems like ours, we would expect not to find them.

[firebrand]

Democrats are the way stars lie to each other.

[Fiddlstix]

BTTT

[reagan_fanatic]

Oh man, you have discovered the missing mass in the universe: Teddytrons. They are very very heavy.

Ahh, yes - the infamous Teddytrons. They also sink when exposed to water.

[cookcounty]

The chances of another planet like earth is probably 1 in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000.

Of course, it could be better odds than that. Then again, it could be even longer odds. Nobody has any idea. Except the BSers, the nuts and the sci-fi dreamers. They know. Somehow they just know, deep in their hearts.

[buwaya]

Absolutely.
Planetary discovery techniques are based on peturbations in light output of the parent star. It takes a large and close planet to do this. So it is no surprise at all that this is the sort of planet that has been found.

[Erasmus]

It's also possible that current technology can ONLY detect planets that are large, therefore gaseous, therefore not sustaining life.

Astronomers are hoping to improve their observation capabilities in the years to come to the point where they can detect Earth-size planets.

However, they can make some tentative conclusions based on the planetary systems they have already seen, with these gas giants.

They can tell not only the approximate size of the planet, but also its orbital period and can get an estimate of its orbital radius.

With this information, they can use current general models of planetary systems construct a variety of hypothetical ones including the star and the planet or planets they have been able to observe.

I think that they have essentially concluded among the likely systems that could exist with the large planet they have already identified, in the orbit they have identified, none of them include an Earth-like planet; i.e., one about the size of Earth in an orbit producing the necessary surface temperature range.

[bwteim]

or these fearless statements:

"I think there is a world market for as many as 5 computers." - Thomas Watson, IBM, 1943.

"There is no reason why anyone should want to have a computer in the home". - Ken Olson, founder of DEC, 1977

"640 Kb should be enough for anyone." - Bill Gates, 1981

[Political Junkie Too]

Our solar system may be unique after all, despite the discovery of at least 120 other systems with planets, astronomers said on Wednesday. All the other solar systems that have been found have big, gassy planets circling too close to their stars to allow them to be anything like Earth or its fellow planets, the British and U.S.-based researchers said.

Were these Registered Planets or Likely Planets?

-PJ

[LiberalBassTurds]

As far as we know, the universe is not "infinite" in the senses in which that observation would matter.

Cite your source. I aware of no math that's proven the finite hypothesis.

LBT

-=-=-