Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Scientists estimate 30 billion Earths
bbc ^ | 3 Jul 02 | Dr David Whitehouse

Posted on 07/03/2002 9:03:47 AM PDT by RightWhale

Scientists estimate 30 billion Earths

By Dr David Whitehouse , BBC News Online science editor

Astronomers say there could be billions of Earths in our galaxy, the Milky Way.

Their assessment comes after the discovery of the 100th exoplanet - a planet that circles a star other than our own.

The latest find is a gas giant, just like all the other exoplanets so far detected, and orbits a Sun-like star 293 light-years away.

Scientists say they are now in a position to try to estimate how many planets may exist in the galaxy and speculate on just how many could be like the Earth. The answer in both cases is billions.

Virtually all the stars out to about 100 light-years distant have been surveyed. Of these 1,000 or so stars, about 10% have been found to possess planetary systems.

So, with about 300 billion stars in our galaxy, there could be about 30 billion planetary systems in the Milky Way alone; and a great many of these systems are very likely to include Earth-like worlds , say researchers.

Better grasp

The 100th new planet circles the star HD 2039. It was found by astronomers using the Anglo-Australian Telescope as part of the Carnegie Institution Planet Search Program.

The Jupiter-sized world circles its star every 1,210 days at a distance of about 320 million kilometres (200 million miles).

Astronomer Dr Jean Schneider, who compiles the Extrasolar Planets Catalogue, told BBC News Online: "The 100th planet is symbolic and important.

"The first discoveries concentrated on short orbital periods because of the limited timebase of observations. Now, we are learning more about the statistics of long orbital periods and know to what extent our own Jupiter is exceptional or not."

New telescopes

With the new world, astronomers say that they have just about finished surveying all the Sun-like stars out to a distance of 100 light-years from Earth.

Current planet detection technology - based on the "wobble" induced in the parent star by the gravitational pull of the orbiting planet - can only detect worlds about the mass of Saturn or larger. Earth-sized worlds are too small to be seen.

But even in this "biased" survey of giants, the smaller worlds predominate - which makes astronomers think that Earth-like worlds do exist. They may even be as common as Jupiter-sized exoplanets.

And if stellar statistics gathered in our local region of space are applied to our galaxy of 300 billion stars, then there may be 30 billion Jupiter-like worlds and perhaps as many Earth-like worlds as well.

Astronomers will have to wait for a new generation of space-based telescopes incorporating advanced detectors before they can detect Earth-sized worlds orbiting other stars.


TOPICS: Culture/Society; Extended News
KEYWORDS: earth; galaxy; goliath; planets; space; xplanets
Navigation: use the links below to view more comments.
first previous 1-20 ... 121-140141-160161-180181-186 last
To: Vast Buffalo Wing Conspiracy
"Who says that "the Fall" occured inside Time? If one is outside Time, then by definition there can be no death, since death is a product of Time - that is to say, of change and evolution. Mankind Falls, and is therefore in Time, and therefore can die, can change, can evolve."

In which case man is not the product of evolution, since man existed before evolution, likewise for everything else. I don't have a problem with micro-evolution (minor changes over time without creation of a new species).

"And since evolution also recognizes that animals also bring forth their own kind, there is no contradiction there, either."

Evolution, macro-evolution to be specific, requires one kind to mutate over generations into another, so at some point you have one kind bringing forth a new kind.

If you want to try and hammer a square peg into a round hole, be by guest, but creationism and evolution are incompatible and name calling and insulting people isn't going to change that or win anyone to your side.
181 posted on 07/04/2002 8:22:46 PM PDT by Grig
[ Post Reply | Private Reply | To 178 | View Replies]

To: Vast Buffalo Wing Conspiracy
Smart money is on my side

Find one. Just one other earthlike planet. A place where we can simply land, clear a field, plant crops, and go from there for a few million years.

Then maybe we can talk about money.

182 posted on 07/04/2002 8:27:45 PM PDT by RightWhale
[ Post Reply | Private Reply | To 180 | View Replies]

To: Vast Buffalo Wing Conspiracy
"Science will simply deal with the evidence as it is discovered."

I don't have that much faith in scientists. Politicaly incorrect studies are avoided, and when they are done they are attacked and suppressed. What could be more politicaly incorrect than something that virtually proves creation? It's all theoretical of course, I don't expect it to happen untill after the second coming. :)

183 posted on 07/04/2002 8:28:19 PM PDT by Grig
[ Post Reply | Private Reply | To 176 | View Replies]

To: Grig
the show was a twilight zone.... the wife has the complete series and it is cool to watch them... rod serling is a master. they end up shooting him back into space to set things right again.

my theory on the planets, they are moving towards the sun, and will eventually crash into it, but before they do, each will pass through the ring of life, the precise distance from the sun to sustain life....
184 posted on 07/04/2002 8:42:05 PM PDT by teeman8r
[ Post Reply | Private Reply | To 172 | View Replies]

To: shirleyvalentine
Without that big moon no planet will be an earth

And you point is? Does life required a moon?

185 posted on 07/05/2002 4:51:26 AM PDT by RadioAstronomer
[ Post Reply | Private Reply | To 179 | View Replies]

To: teeman8r
"the show was a twilight zone.... "

I'm pretty sure there was a movie of the same thing. I clearly remember him reading text reflected in a mirror and driving on the wrong side of the road before they figure out what happned after he gets back. In the end he dies when they launch him back into space and things go wrong when he has to dock with his mirror self. It was old, but in color, and too long for a TZ episode.

186 posted on 07/05/2002 8:50:58 AM PDT by Grig
[ Post Reply | Private Reply | To 184 | View Replies]


Navigation: use the links below to view more comments.
first previous 1-20 ... 121-140141-160161-180181-186 last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson