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Posted on 06/13/2002 9:51:07 AM PDT by dead
The first solar system that looks like it could harbour an Earth-like planet has been found, after a 15-year search.
An international team, including two Australians, announced early today that it had identified the first Jupiter-like planet orbiting a star - at nearly the same distance Jupiter is from the sun.
The star, 55 Cancri in the constellation Cancer, was already known to have another giant planet much closer in, zooming around it in a fortnightly orbit.
A team member, Chris Tinney, of the Anglo-Australian Observatory, said calculations showed that a planet similar in size to the Earth could survive in a stable orbit between the two.
Finding such a system had been a long-term goal of planet hunters. "It's a very significant discovery," Dr Tinney said. "There's no place like home, but we're definitely coming closer."
Earth-sized planets cannot be detected with present technology, but this system would be one of the first places to look when NASA's Planet Finder space telescope is launched later this decade, he said.
Astronomers detect planets from the way they make their star wobble. Jupiter, for example, induces a wobble of 11 metres a second in the sun.
All up, 15 new planets were announced by the team, led by the world's top planet hunters - Geoffrey Marcy, of the University of California, Berkeley, and Paul Butler of the Carnegie Institution in Washington.
This takes the planet total to more than 90 since the first one outside our solar system was discovered in 1995. The latest include the smallest so far - a planet 40 times bigger than Earth, orbiting very close to its star in the constellation Auriga.
Four of the 15 planets were found using the Anglo-Australian Telescope in NSW, taking its total to 10. Most of them are gas giants, like Jupiter, but they are much closer to their stars and with eccentric, rather than circular, orbits as short as a few days.
The latest planet, discovered by the University of California's Lick Observatory, is more than four times Jupiter's size, and slightly further out in an elongated orbit.
Cancri is 41 light years away, and at five billion years is a similar age to the sun.
They're detected using the red/blue shift in the star caused by the planet orbiting it. All planets exert gravational force on their star, just like the star exerts gravational force on the planets. The difference is the star is much much bigger than the planet. Consider this: Jupiter appears to orbit the sun, but they both really orbit a point a few miles just outside the corona of the sun (the center of mass). Earth does orbit the sun, but only because the center of mass is a few feet from the center of the sun.
If I were at Alpha-Centuari A, looking back at Sol, I would see Sol move in a sinisudial pattern, matching the period of Jupiter's orbit, with a slight wobble to that because of Saturn. (We would not be able to detect the wobble caused by the other planets, because the equipment and techniques are not that refined.)
For more information, and a more-precise explanation, see Exoplanets.org
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An apt comparison. I believe they have actually imaged a few of these, just a spot of light next to a really big spot of light, but most of the extrasolar planets so far have been found by other methods such as a subtle shift in the starlight spectrum or infinitesimal but regular change of light output.
You gotta get with the program. Mr. Spock can glance at his instrument panel and read out the entire contents of a system from several light-years out.
Astronomers have announced the discovery of 13 new planets among the stars, including one inhabiting a solar system similar to our own.
The newcomers bring the tally of planets found orbiting stars outside the solar system to more than 90.
They include one Jupiter-like planet orbiting a Sun-like star at the same distance as the Jovian giant is from the Sun in our system.
The team, led by US planet-finding pioneers Geoffrey Marcy and Paul Butler, also announced the discovery of the smallest extrasolar planet ever detected - a world with a mass 15% that of Jupiter and 40 times larger than the Earth.
The planetary system similar to the Sun's belongs to the star 55 Cancri, 41 light years away in the constellation of Cancer.
Dr Marcy, professor of astronomy at the University of California at Berkeley, said: "All other extrasolar planets discovered up to now orbit closer to the parent star, and most of them have had elongated, eccentric orbits.
"This new planet orbits as far from its star as our own Jupiter orbits the Sun."
The star was already known to have another planet, discovered by Marcy and Butler in 1996. That planet is a gas giant slightly smaller than Jupiter that whips around 55 Cancri in just 14.6 days at a distance one 10th that of the Earth to the Sun.
The newfound planet orbits at about 5.5 times the Earth-Sun distance (5.5 astronomical units, or AU), which is comparable to the 512 million gap between Jupiter and the Sun.
It is between 3.5 and five times the mass of Jupiter, and its slightly elongated orbit takes it around the star in about 13 years - quite close to Jupiter's orbital period of 11.86 years.
Story filed: 18:17 Thursday 13th June 2002
We could leave and let Islam rule over the earth. At the rate they are killing themselves and blowing everything up, we could return one day to find the problem gone.
Imagine there's no jihad...........
Could Islam rule over earth even if we all left leaving no one but Muslims? I would bet that someone, maybe Egypt or Iran or Turkey, would rise up from within and say enough is enough.
I disagree - the very complex and resource comsuming ultra-tricorders fitted on to Federation vessels must be within a planet's reasonable orbit.
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