The density mentioned (0.059 grams per cubic centimeter) is the overall density of the planet. Most probably it has a much much denser core, solid or thick super hot fluid, like all gas giants. It doesn’t mean that the whole planet has the same cotton candy density (0.05 grams per cubic centimeter) from the top layers down to the core ;-)
On the funny side of this, what would happen if we kept adding cotton candies at an empty/isolated place in space? After some critical mass, the cotton candies would collapse under their own weight/mass and a new asteroid would be created. If we kept adding even more candies a further collapse would create a new planet :-)
Imagine stacking/accumulating different materials. A planet made just of bananas, a planet made of only water, a planet from rice…
/note to self - check if there is such a planet simulator available
What fascinates me is that if you had enough cotton candy, it would be a black hole. I don't mean it would collapse into a black hole, I mean even at a uniform density of 0.05 grams per cubic centimeter, it would already be a black hole.
We're so used to surface area scaling at r^2 and volume scaling at r^3 and the weird effects that can have (never scale up an exothermic reaction), but the maximum amount of matter that can exist in a volume without creating a black hole scales by r^1. Even with cotton candy, that r^3 is going to out-scale r^1 at some point.
It's an interesting thought experiment for algorithm complexity as well. Can you actually retrieve an element from an array in constant time regardless of the size of the array? In the extreme case, the drive containing the array must have r proportional to the size of the array to avoid becoming a black hole. Assuming the query and element travel along the drive at the speed of light, retrieving the element still takes time proportional to the size of the array.
Worth noting that even setting aside weird black hole physics, in the real world the amount of storage available given some information density and some maximum constant access latency is bound in r^3 by the speed of light, and therefore array access is not really constant time but O(∛n). This isn't some abstract ivory tower thing but the way computers actually work - due to cache hierarchies you will find that working with a 100 byte array is much faster than working with a 100 megabyte array, which is much faster than working with a 100 terabyte array. Every time the data gets larger, it gets further away...
I have struggled to find an established name for this value. I thought it would be something called the "Schwarzschild density", but no luck. Famously, the [someone's name??]-density of the observable universe just happens to be very close to the density that would tip the universe over into being a very large black hole
But given that the universe is expanding, if we're close to this density doesn't that mean that the density used to be higher than the threshold at some point?
This is why when talking about the big bang physicists talk about the inflation field at the start of it. The primitives in the pre microsecond universe have to be different from a black hole otherwise there's no way to un black hole yourself.
As you added more and more cotton candy you would begin to compress the centre under the pressure, and you would get some heating from this. I think there's a good change you would melt and cotton candy and eventually it would re-solidify into an enormous boiled sweet core, with a diffuse envelope of cotton candy around it.
I mean, when we talk about the Jovian planet we believe it has a core of solid metal hydrogen, the only real problem getting an oxygen planet is there is much more hydrogen/helium in the universe so that's what it's going to be made out of.
The software to detect the transits seems like a fun challenge. Locating each star in each of the images taken, then comparing their brightness in each one. Seems simple enough until you then realize your literally dealing with astronomically large numbers.
>In data taken between 2006 and 2008, and again from 2011 to 2012, the WASP-South observatory detected periodic transits, or dips in light, from the star WASP-193. Astronomers determined that the star’s periodic dips in brightness were consistent with a planet passing in front of the star every 6.25 days. The scientists measured the amount of light the planet blocked with each transit, which gave them an estimate of the planet’s size.
I'm not a physicist nor astronomer so I apologise if I sound arrogantly dismissive about something I am clueless about. But how can they be so confident about something from a single measurement? Couldn't there be other things causing dips in light, like dust clouds/asteroids also passing in front of the star at the same time? It seems like a flimsy way of figuring the size of another astronomical body.
When we think about making an observation with a telescope, we might think of someone in a crow's nest looking at a far away island, and think: it could be debris, it could be a boat, it could be a smudge on the telescope, it could be a whale, etc. etc. There are several reasons why this intuition breaks down looking at the stars.
For one, astronomical systems are extremely regular. The same thing will happen, over and over, almost the exact same way, millions or billions of times before anything appreciably changes. It's extremely rare to find a system that is in the midst of significant change. We do find them, of course, and study them, but we do so after passing over countless "boring" areas of the sky.
This regularity means that anything we look at is extremely likely to be in a very stable configuration, and we can use our knowledge of orbital mechanics to rule out all sorts of things like weird dust clouds orbiting the star, which would not be stable (or would look very different if they were). Realize also that we stare at these systems (or at least check up on them periodically) for years at a time -- in this case they said 2006 to 2008, and again 2011 to 2012. So we can easily rule out some random thing passing between our telescope and the star precisely every 6.25 days for 3 years. It must be something stably orbiting the star.
We can also use the exact shape of the "light profile" to be pretty certain about the shape of the object passing in front of it. Over dozens or hundreds of observations, we see the same characteristic dip in light at the exact same period every time, and it matches the shape of a circle passing in front of another circle. It doesn't happen immediately, because the planet spends a bit of time only partly obscuring the star, and we can use this to discern that it is roughly circular in shape. We use this profile and the amount of reduction to calculate the size of the planet. Asteroids would be far too small to detect (we can't even detect all the asteroids in our own solar system!)
Also realize that when they say "light", they're usually looking at a whole spectrum of light. It's not one number that dips, it's a whole waveform that subtly changes. A dust cloud would be partly transparent, differently for different wavelengths, and change the light in a different way. In the extreme cases we can even use this to guess whether the planet might have an atmosphere, because it changes the waveform differently at its edges.
Space is also really empty. A bird might pass in front of your telescope on land, but in space, it's almost certain that nothing is going to randomly pass between you and what you're looking at, even over years.
And finally, even with all this, they spend years analyzing the data before they can be confident enough to make claims like this. There is a lot of data and a lot of time spent on it, and it's the culmination of many different lines of evidence. It's certainly not "flimsy".
IANAPNA either, but a solid object like a planet blocks light differently than dust clouds. Dust clouds, even dense ones, still allow some wavelengths through that planets do not. I would guess that's what allows them to be confident that it's a planet.
How do you get an object of 44 Earth masses with the average density of styrofoam?
The obvious starting point I guess is a core of very light elements, and a really really extended atmosphere. But an atmosphere thins out exponentially, more steeply the higher the gravity. So for an atmosphere to help much, those 40ish Earth masses of hypothesized core need to be spread out a whole lot already. It seems like a difficult planetary engineering problem -- spin it up almost to bursting?
So taking that to be too silly, the core must be only a small fraction of the mass: a big gas cloud with a nugget in the center. I'm not sure that could work, but it's what I'd try to work out next.
It's basically explained in the article: it's probably just very hot—the atmospheric scale height[0] is proportional to temperature. The open question (per the article) is why it got so hot, because they don't have a model for that. ("It certainly requires a significant deposit of energy deep into the planet’s interior, but the details of the mechanism are not yet understood.“")
I'm imagining an orbital trailer park for nanorobots, with wispy power cords and network cables trailing all over the place as everyone participates in one big LAN party.
The idea of a planet 1.5x the size of Jupiter, but 1/7th the mass...is very unintuitive from a gravitational perspective. Maybe it's spinning so ungodly fast that centrifugal forces are keeping it puffed out?
Or it could be alien made. Like a dyson sphere - but a planet, with solar capture on the shell. Build everything without all the mass, add magnetic shoes and other tech to make living in 0g a reality.
It's weird to me they can make such assessments with confidence when we didn't even know the density/composition of Jupiter to any certainty until Hubble was around just in time to observe Shoemaker-Levy plow into it and eject enough surface matter
AFAIK the Shoemaker-Levy impact was useful for other studies, but not so for the density/mass of Jupiter (also as per your link).
Jupiter is full of surprises still (mostly about its interior). However, the assessments made in this article about the mass and radius of the planet are using very basic physical laws (mostly Kepler laws from the 1600s).
Usually, you would see the sign of this in the data - because we can actually detect the gap between the planet and eventual rings. But if the gap is extremely small, then it could be a possibility.
Until evidence to the contrary is found, it is not reasonable to assume that aliens are going around making planets. I say no, we have no reason to make such an assumption. If we think we've done a good job enumerating all of the ways that a planet can naturally form, that would provide reason to suspect that we've missed something. But pinning it on aliens capable of planet-scale engineering is quite the jump.
For example, rather than a hydrogen storage tank, perhaps this was once a primordial rogue planet, a frozen ball of hydrogen hurtling through space. If it was then captured by a star's gravity well, and gently warmed by its newfound environment, it could expand into the anomaly we see today. Perhaps in another hundred years, we'll see that it's shedding its gas into a ring around the star. This sounds improbable, but I find it less incredible than immediately jumping to intelligent life.
Because of all the things humanity has learned about the universe, none of them has turned out to be aliens or evidence of aliens. You can theorize it all you want, but so far every time the universe has just turned out to be a big, strange place.
I beg to differ. In a trillion plus rocks floating in a vacuum and we colonize this one, I don’t see why candy flos planets controlled by beings is so far fetched.
You said "proven" and now you're saying "[not] so far fetched." I still think it's far fetched, but I'm satisfied that you aren't claiming proof anymore.
On the funny side of this, what would happen if we kept adding cotton candies at an empty/isolated place in space? After some critical mass, the cotton candies would collapse under their own weight/mass and a new asteroid would be created. If we kept adding even more candies a further collapse would create a new planet :-)
Imagine stacking/accumulating different materials. A planet made just of bananas, a planet made of only water, a planet from rice…
/note to self - check if there is such a planet simulator available