So Many Lonely Planets with No Star to Guide Them

Nature ^ | Wednesday, May 18, 2011 | Nadia Drake

[SunkenCiv]

Scattered about the Milky Way are floating, Jupiter-mass objects, which are likely to be planets wandering around the Galaxy's core instead of orbiting host stars. But these planets aren't rare occurrences in the interstellar sea: the drifters might be nearly twice as numerous as the most common stars.

"This is an amazing result, and if it's right, the implications for planet formation are profound," says astronomer Debra Fischer at Yale University in New Haven, Connecticut.

To find the wanderers, scientists turned their telescopes towards the Galactic Bulge surrounding the centre of the Milky Way. Using a technique called gravitational microlensing, they detected 10 Jupiter-mass planets wandering far from light-giving stars. Then they estimated the total number of such rogue planets, based on detection efficiency, microlensing-event probability and the relative rate of lensing caused by stars or planets. They concluded that there could be as many as 400 billion of these wandering planets, far outnumbering main-sequence stars such as our Sun. Their work is published today in Nature1.

[SunkenCiv]

• Rogue Planet Find Makes Astronomers Ponder Theory [2005]

[SunkenCiv]

Thanks Quix for putting me onto this one, via this link in FReepmail:

• Kiwi astronomers help discover wandering planets

It suddenly occurs to me that I didn't check to see if this had been posted. [blush]

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[SunkenCiv]

Thanks Quix.

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Google news searches: exoplanet · exosolar · extrasolar ·

[KoRn]

When our Sun goes, this will probably be the fate of our outer ‘Gas Giant’ planets. Earth and the inner Solar System planets are gonna ‘go down with the ship’.

[bigheadfred]

Space.

The final frontier.

These are the voyages...AAAHHH!!! BREAK RIGHT!!!
NOOOO!!! LEFT!!!!! BREAK LEFT!!!! AAAAHHHH!!!!

[dangus]

How do you mean “when the sun goes”? Would the white dwarf that the sun will become not be able to retain the gas giants? Or would the red giant that it will first become somehow drive off the gas giants?

[dhs12345]

Yup. By then we will be ethereal beings capable of cross-dimensional astro-projection... or we will have destroyed ourselves billions of years prior to “the end.”

[SunkenCiv]

[Chode]

talk about DarkMatter...

[deoetdoctrinae]

All the lonely planets, where do they all come from?

[bigheadfred]

WHY am I SOOO thirsty???

[SunkenCiv]

That was inspired... heh heh...

[SunkenCiv]

Far enough away is actually the way I prefer planets, but que sera, sera.

• Lonely Rogue Worlds Surprisingly Outnumber Planets with Suns
• 'Free-floating' planets found with no star in sight

and from the FRchives:

• First Alien Planet From Another Galaxy Discovered
• Planet Found With Comet-like Tail
• Scorched Alien Planet Has a Comet Tail (153 light-years from Earth)
• Cosmic Bullet Fired by Exploding Star
• 'Jupiter swallowed planet 10 times the size of Earth'
• Comet-like tail discovered trailing planet Mercury
• Will Mercury Hit Earth Someday?
• Venus' Tail of the Unexpected
• Moon has liquid core just like Earth...reveal sensors left on surface by astronauts 40 YEARS ago

[SunkenCiv]

Sometimes I almost miss the sixties. :’)