Seven-Planet System Detected | Hacker News Reader

Seven-Planet System Detected

livasperiklis.com

176 pointsSerene76 comments

Hang on, I thought 'Solar system' means the system orbiting the star 'Sol' i.e. our sun? Isn't the general term 'planetary system'?

Yes, 'Solar' refers to our sun, Sol. So there is only one 'Solar' system which is our own.

I think 'star system' is acceptable as well.

I'm not disagreeing, but genuinely curious: what do astronomers call the "solar wind" in other systems? Referring to every wind by the star's name would seem odd.

Just replace solar with stellar.

This seems like yet another case of unnecessarily Earth/Sol-centric terminology, much like "apogee" being Earth specific such that you have to use "apoapsis" if you want to be generic. I mean, do we really need a new word for every planet, the sun, a star in general, a black hole specifically, and galaxies? http://en.wikipedia.org/wiki/Apsis#Terminology

We should declare terminology bankruptcy to wipe out our existing terminology/language debt, then pick sensible terms for everything. While I'm the topic, we should also do "kilogram"->"grave", "gram"->"micrograve".

When talking about orbits it's very useful to be able to make a distinction between apogee and lunar or solar apoapsis.

You inadvertently gave the solution: "lunar apoapsis", "solar apoapsis", "earth apoapsis".

Much easier than "aposelene/apocynthion/apolune", "aphelion", "apogee".

Shouldn't that be "milligrave" if you're using SI prefixes?

You are absolutely correct.

So, what gets to be "mg"?

I'm not against the idea, but please don't have the new base also start with "g".

Hence "terminology bankruptcy", all existing terminology debt will be erased ;)

I once had a stellar wind, about near blew the doors out my house...

So you see, probably does not work so well.

solar : stellar/star :: coke : soda

It's bizarrely worded, yes. I think what they're trying to say is it's a planetary system very similar to the Solar system. Announcing it as a new "planetary system" would sound much less dramatic, since we've cataloged more than 700 of those.

Are we then not Solarians?

I see what you did there...

I usually hear them referred to as stellar systems. But like my sibling comment said, they are trying to say this stellar system is a second "solar system" due to its similarities.

Many say "moon" when they mean natural sattelitte of a planet

moon != Moon

That's no moon.

Our moon is named Luna.

I've always wondered how Spanish speakers deal with this naming convention— do they have some different naming scheme (tal vez nuestra luna se llama `Moon'?), or is there just not an equivalent proper noun?

Interestingly in Norwegian and Swedish "solsystem" can mean any planetary system, but if you say "solsystemet" i.e. "_the_ Solar system" you typically refer to our own. http://sv.wikipedia.org/wiki/Solsystem

In this particular case, the title makes sense. According to them, the newly found planetary system is very similar to our solar system. Hence the title "Second Solar System detected".

Why not link to the original article, instead of some weird half-Greek aggregator blog?

http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151...

I found this site interesting for more information: http://www.openexoplanetcatalogue.com/system.html?id=KOI-351...

The star is about the same size as sol so it might be possible to live on some of the moons of the edge planet if we ever got there.

I think you found my new favorite website.

Some of the closest habitable neighbour stars.

tau Ceti: http://www.openexoplanetcatalogue.com/system.html?id=tau%20C...

Gliese 876: http://www.openexoplanetcatalogue.com/system.html?id=Gliese%...

HD 62509: http://www.openexoplanetcatalogue.com/system.html?id=HD%2062...

Gliese 581: http://www.openexoplanetcatalogue.com/system.html?id=Gliese%...

This is an interesting example, useless at first glance but you know there are a lot of smaller planets closer to the star. http://www.openexoplanetcatalogue.com/system.html?id=HR%2087...

Seriously, the orbit visualizations are pretty cool: http://www.openexoplanetcatalogue.com/system.html?id=KOI-351...

Was Gliese the one where the aliens from the Battleship movie came from? I think I read somewhere some scientist picked it for the movie.

"The star is 2500 light years away from Earth."

Found that on google. Doesn't seem so far away :P

Yeah, unreachable without FTL travel.

It would take about 15.6 years [0] to reach the star on a ship capable of a constant 1G acceleration.

Here is the explanation and equations: http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.h...

[0]: https://news.ycombinator.com/item?id=6637131

Does this take the needed deceleration in account? If we are to land there anyway :P

Yes, but the real problem is fuel( even with antimatter ). And radiation.

I agree that the real problem is fuel, but 10 years isn't quite long enough if you are going to accelerate halfway and decelerate halfway to arrive at low speed. For a 2,500 light year trip composed of two 1,250 light year legs, the time experienced by the ship will be (in units where c and a are both approximately 1):

2 * T(1250 lyr) = 2 * (c/a) arccosh (ad/c^2 + 1) = 2 * arccosh(1250 + 1) = 2 * 7.8 = 15.6 yr.

15.6 years for the passenger, thousands of years from our perspective.

Meh. People were willing to go half-way across the world to try living somewhere new, probably never to return. Announce the trip, and you'll have to weed out volunteers pretty viciously.

So after a few subjective years, you will be overtaken by newer and faster ships, and when you arrive, there will be a flourishing civilization already there to greet you.

And the people in the faster ships will be your grandchildren, yup. Plot of Heinlein's "Time for the Stars", pretty much.

I was thinking of "Far Centaurus" by A. E. van Vogt, but I'll look up the Heinlein as well now.

I read this when I was younger and had no idea what it was called until now. I've tried to remember it a bunch. Thanks!

It is dubious we will ever travel faster than 10% the speed of light.

But a probe might be able to.

Not dubious - speculative:

https://news.ycombinator.com/item?id=4534359

https://news.ycombinator.com/item?id=6238297

Although, I certainly wouldn't bet against it long term.

If you did, you'd really be betting on your ability to collect / pay up the debt.

What does that even mean? Of course it is reachable without FTL travel. Besides time dilation which could make it a subjectively short trip, there is also cryogenics and other life extension techniques that could get us there.

If you accept any ship could get there, you might as well consider that space travel isn't the only technology that will advance.

> there is also cryogenics and other life extension techniques that could get us there.

You are aware those don't actually exist?

People assume they will exist, but we have nothing to base that assumption on except "it would be cool".

Besides the fact I think it's clear they will exist (assuming we don't destroy ourselves somehow), I already addressed that. We're already talking about things that don't currently exist. I can talk about a ship to Mars which doesn't currently exist. But both a Mars trip and cryogenics seem pretty reasonable to me.

> it's clear they will exist

???? Based on what exactly?

> But both a Mars trip and cryogenics seem pretty reasonable to me.

You think those are similar? We could do a Mars trip today with enough money. Every bit of money in the entire world would still not get you cryogenics - it requires a new idea that doesn't exist right now.

That is arguable, we have the freezing people but going. Sure it is being done in a very destructive way to the human body, it is a bet though that at some point in the distant future technology will get good enough that the current freezing method could be reversed.

There are animals that are naturally capable of freezing and thawing. We don't have to invent the process, we only need to adapt it. I bet it would be cheaper than a Mars trip.

We can't even freeze and thaw a steak and have it taste the same… let alone any living mammals.

just three years at warp 9 =)

It's strange to realize that even at Warp 9, it still take a very long time to get anywhere much.

In the TV shows and movies, they never seem to spend more than a few days at a time going anywhere at warp speed.

Hell, in the new movies, you can transport from Earth to the Klingon homeworld instantly, and fly there in like 20 minutes.

Hell, in TOS they went to the edge of the galaxy (or back) in practically no time, under their own power.

> In the TV shows and movies, they never seem to spend more than a few days at a time going anywhere at warp speed.

There are a few canon reasons for this:

1) Ignoring special episodes (and all of Star Trek Voyager) where they use a contrivance to hurl the ship tens of thousands of light-years, the working range of a starship on Star Trek is relatively small:

* The distance to the Romulan Neutral Zone, on the outer fringes of Federation Space, is only 28 light years away from Earth.

* Deep Space 9 (so named because it's on the outer frontiers of known space) is 70 light years away from Earth.

* Oo'nos, the Klingon homeworld, is ~100 light years away from Earth.

2) Ship speed exponentially increases as warp factor increases, and by the time the USS Enterprise-D is in service, warp 9 is fast, but not "I need to get there immediately because every plot shown on TV is an emergency" fast. The maximum sustainable speed for the Enteprise-D is warp 9.6, which is 1,909 times the speed of light. This would allow Picard to reach even Qo'nos from Earth in under 3 weeks.

3) With the exception of the JJ Abrams franchise (where they seem to keep going back to Earth after every mission), the ships featured in Star Trek are generally exploratory: between each episode, they'd roam their mission areas performing routine work. The episode plots would generally revolve around them dealing with an issue that happened to be close to wherever they happened to be at the time.

Of course, being a set of TV series and movies, liberties with distances were routinely taken. For example, in the first episode of Enterprise, they say Qo'nos is 4 days away from Earth at warp 4.5, which would place it less than half the distance between Earth and Alpha Centauri, the closest star system.

Most of the time they're moving at the speed of plot. It's a log scale I think so warp 9.9 is much faster than warp 9. Except whenever they remember the terrible idea they had part way into The Next Generation when they put a speed limit on space travel.

The TNG scale have a asymptote at Warp 10. The TNG scale come from a draw, and actually have a very complex formula derive from these hand draw graph, but can be approximated to a exponential scale below Warp 9.

TOS (and Enterprise) uses other scale with a much more simpler math exponential formula, were the same Warp factor is less quick that in TNG scale.

Actually the TNG scale is because Rodenbery like to give the impression that the ships are more fast that in TOS but he like to avoid using Warp 10 and huger numbers.

You can check it in http://en.memory-alpha.org/wiki/Warp_factor , appendices section.

the entire system lies within one Earth orbit

Perhaps little chance of life as we know it.

Moons orbiting the outermost gas giant could support earth like life.

Although if the gas giant is anything like Jupiter those moons are probably getting smothered in radiation that is dangerous to Earth-like life.

Jupiter is a special case. Due to orbital resonances with the galilean moons the inner moon of Io experiences extreme tidal heating, which results in extensive vulcanism (Io's surface is the youngest in the solar system because of this). This creates a sulfur dioxide atmosphere around the moon which gets stripped off by Jupiter's strong magnetic field after which it eventually gets turned into plasma and forms the inner radiation belts around Jupiter.

Without those things happening the radiation environment would be far lower. Saturn, for example, has much milder radiation levels.

Also, life tends to evolve to tolerate whatever level of natural radiation background exists. Most, but not all, life from Earth would have trouble with the radiation levels near Jupiter but life that originated on a moon around a gas giant would probably be fine.

If anyone wants an idea for a scifi story posit a technological species arising on a planet that experiences significant levels of background radiation. Such a species would be able to more easily tolerate working with radioactive materials, as would their ecosystem. For example, something like the Chernobyl accident may not even be a serious problem for them, since every organism would be able to tolerate radiation exposure. They might be able to operate fission reactors without much shielding. And they might be able to tolerate the radiation exposure of interplanetary space without needing any special shielding at all.

Not necessarily, if the star is smaller and cooler than ours.

It's not, it's slightly larger and more massive than the Sun. Only the outermost planet is within the habitable zone, but it's a gas giant.

This is entirely dependent on the luminosity of the star. The intensity of the light diminishes according to an inverse-square rule and is dependent on the star's temperature and diameter.

Emphasis on "as we know it". With the wild diversity of living conditions we have found just here on Earth, I hope that we find an equally diverse array of life Out There, spanning a wide variety of conditions that we considered too hostile.

Seven planets, and it fits into one Earth orbit?

Hey, it's Kerbin!

Why aren't we seeing any electromagnetic signals from any of these systems?

We probably wouldn't even if there was a copy of Earth there.

Kepler 62 seems interesting

Agreed! What I found most interesting about this article is that our own solar system seems fairly unique (I know, small sample size). Kepler 62 is the only one that has an Earth-like planet at about the same distance from the central star, and even in that case that particular planet is the outermost one in that system. I guess I always assumed that due to various physical laws that other star systems would be pretty similar to ours in regards to planet-types (hot-rocks vs middle-ground vs gas-giants vs coldies) at various orbits, but there seems to be much more at play here (star size, etc, etc). Truly fascinating.

You're not the only one; astronomers have also been surprised. But you have to keep in mind that our data right now is very incomplete. Kepler only operated for four years. You'd need a minimum of three years to detect a planet with a one-year-long orbit. (The first two years give two blinks when the planet crossed in front of the star, and then the third blink should be exactly a year later.) As they analyze the data in more detail, they'll probably find planets with longer-period orbits, but possibilities are limited.

Just a big yellow screen here (firefox 24)

it eventually loads in Firefox 17 but it is yellow for a fraction of a second (probably javascript that is slow to load?)

... and I know the Guy who created it!

When are we going to lazer a communique to one of the planeted systems?

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