""It is about 70 percent bigger than Jupiter, the Solar System’s largest planet, but less massive, making it a planet of extremely low density. Its mean density is only about 0.2 grams per cubic centimetre, or about the density of balsa wood,"

Perhaps the Magratheans are using IKEA for their new planets?

The accepted JSI (Journalists SI) for a density that light should be that it would float on water surly

"And it the planet's density, or lack thereof, that has the boffins baffled."

Ooh, ooh, I know sir, I know. <fx: waves hand at back of room>. It's a Dyson sphere it is, a real one. Just like the thing that they found Scotty on in Star Trek next gen.

Do I get a Gold Star now?

TeeCee

and orbiting at a few miles from its parent star ? How many football fields is that exactly ?

More importantly, with a density like that, how can it possibly keep an atmosphere when it's being bombarded at such short range by the power of an intergalactic nuclear fusion plant ?

It's probably irrational, but I can't get my head round the idea of the biggest planet yet discovered bobbing up and down in some water.

> The accepted JSI (Journalists SI) for a density that light should be that it would float on water surly

Good point - how about 'Witches' as a density unit ?.. or Ducks for extremely dense things...

"The planet is so diffuse, that its gravity only has the most tenuous of grasps on its upper atmosphere: the team at the Lowell Observatory who made the discovery suggests the planet probably has a diaphanous tail of material spiralling towards its parent star."

Why then does the picture show the tail going AWAY from the parent star?

Because artists are wankers.

... the existence of weapons of mass destruction. Brilliant!!!

Sounds like another "find one bone = new species. I smell grant money!

Saturn is a floater too.

"and orbiting at a few miles from its parent star ?"

Lots of football fields, I'd say, being 4.5 million miles...

But MY theory is that this planet is actually just the place where Bacchus keeps corks for all that wine of his. The cork planet as support for "intelligent" design, who'd have thought of that! Or if you prefer, the cork planet as an endorsement of enology...

The major problem facing us here on Earth is a shortage of clean energy. If we could put something 121,536 km in radius into orbit around the Sun at roughly 7.2 million km distance, the sunlight falling on its surface would be able to generate more than 100 times the energy per square meter than reaches Earth, or about 46,395,708,788,736,000 HP, give or take a few million. Even with only a 5% efficiency, that's still 2,319,785,439,436,800 HP, or 1,730,559,937,819,852,800 watts. You could really light up a few pubs with that.

Now, if we assume an intelligence capable of making a flat or concave disk of that size, it is reasonable to further assume they've got the technology to keep it flat-side to their own star, and to beam the collected energy to pretty much wherever they need it within their own planetary system. We can further guess that most of their heavy industry is in space, and not polluting the surface of their home planet, since they have obviously solved the "beanstalk" problem

A dense, circular metal plate could easily appear to be a less-dense sphere if you're expecting to see a sphere. This *might* be evidence of a distant civilization.

Or it might be the plate of birth of the Flying Spaghetti Monster.

...I'm backing it IS the home of the Flying Spaghetti Monster!!

You have all been warned.

Sorry, but it's not a proper Dyson sphere. A proper Dyson sphere is built around the star it orbits, so we wouldn't see it at all.* The whole point is to encapsulate the star to collect all of the energy it generates.

* Okay, we may be able to detect it in specific bands of radiation or by gravitational effects.**

** Speaking of which, anyone think this may be an explanation for at least some small portion of the dark matter out there?***

*** Pedantic and/or better-informed corrections welcome.****

**** Sorry for all the footnotes. I have to stop reading Terry Pratchett books...

But not as we know it.

I like the vast alien hunk of technology angle. Something like a giant Culture plate?

It could be a binary-star system where only one of the stars is encapsulated. This would have the advantage of collecting not only all the energy of the interior star but also energy from the external star.

Yes - a Dyson Sphere made out of cork & balsa wood! Will wonders never cease??? ;-)