News / Science & Technology

Comets Discovered Around Distant Solar Systems

This view of comet Hartley 2 was taken by NASA's EPOXI mission during its flyby of the comet and was captured by the spacecraft's Medium-Resolution Instrument, November 4, 2010.
This view of comet Hartley 2 was taken by NASA's EPOXI mission during its flyby of the comet and was captured by the spacecraft's Medium-Resolution Instrument, November 4, 2010.
Rosanne Skirble
A team of scientists has discovered six exocomets outside our solar system.

Research astronomer Barry Welsh at the University of California, Berkeley Space Sciences Laboratory looks for these comets spinning in elliptical orbits around distant stars, leaving their trademark trails of star-lit gas and debris.  

The icy dirt balls - between just five kilometers and 20 kilometers across - emerge from massive discs of gas and dust around the stars, the raw material for new planets. Welsh said the exocomets are formed from these scraps left over from planet formation.

“This is like the missing link, the missing piece in the puzzle. And it reinforces all the planetary formation theories because all the planetary formation theories say you should end up with left-over comets and left-over big hunks of rock, asteroids, and that sort of thing,” he said.

Comets Discovered Around Distant Solar Systems
Comets Discovered Around Distant Solar Systemsi
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At the American Astronomical Society's meeting in Long Beach, California, Welsh reported that he and his colleagues found spectrographic signatures of the six new exocomets orbiting six very young type-A stars, which are only about 5 million years old.  

Although not all the stars harbor exoplanets, the debris disk means they could be present. Welsh said it suggests that across the universe, exoplanets and exocomets co-exist, as they do in our own solar system. “It looks as though they are quite common things.”

Welsh said that if, as experts theorize, comets could have seeded the primordial earth with organic carbon material and water, then comets also may be the key to life elsewhere in the universe. “If comets are universally distributed around, then you could say that the incidence of life could be higher on other planets than we ever thought.”

Back in our own solar system, comets continue to put on celestial shows for Earth-bound observers. People in the northern hemisphere will be able to see an unusual comet in late November of this year, with the highly anticipated appearance of Comet ISON. The newly-discovered comet is predicted to shine as brightly in the night sky as the full moon.

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Comment Sorting
by: SnowballSolarSystem from: Philadelphia
January 27, 2013 1:34 PM
An alternative hypothesis suggests that planetesimals (comets) may form in binary pairs by gravitational collapse at the barycenter between binary stars and their binary companion stars.

And binary companion stars, binary brown dwarfs and binary planets may form at 1:1 resonant (horseshoe) libration orbits around binary stars. Finally, binary moons may form at 1:1 resonant (horseshoe) libration orbits around binary planets.

Then core collapse causes the (wide-binary) binary companion stars, planets, moons and planetesimals to spiral out by feeding on the energy and angular momentum of their close-binary pairs which spiral in until they merge, forming solitary bodies.

As a binary companion star spirals out from its progenitor star, the binary planetesimals formed at the barycenter (which orbit the progenitor star) also spiral out, but some get trapped in inner or outer resonances of giant planets.

In our own solar system, Proxima (Centauri) at 270,000 AU may be the companion star to our former central binary pair with the solar-system barycenter at 29,600 AU, and the planetesimals formed at the barycenter spiral out until they merge, forming the inner Oort cloud. And the asteroid belt (Jupiter's inner resonances) and Kuiper belt (Neptune's outer resonances) are merely two solar system buckets that trapped these planetesimals, some which collided to form dwarf planets. The other solar system resonances interfere with one another: Jupiter's outer resonances interfere with Saturn's inner resonances and etc. Then our central binary pair merged at 4,567 Ma, forming the chondrules and short-lived isotopes and Proxima's binary pair may have merged at 542 Ma, bringing on the Cambrian Explosion of life.

by: Rob Swift from: Great Britai
January 13, 2013 4:08 PM
The missing link, what we are all waiting for, is yet to be found. ( in deep space. )

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