Transit Method Reveals Many Extrasolar Planets

eldavojohn writes "You might recall not too long ago the first photo of an extra solar planet or, more recently, the mapping & speculation on these planets that lie outside our own solar system. Long since those first few spotted in the 90s, we're now starting to find them in droves due to the popularity of a method that relies on the planet passing directly between the viewer on earth and the star that it orbits. Be sure to check out Space.com's list of the most interesting extra-solar planets. Will we ever find Earth 2.0 candidates?"

Comments

Pegs that variable in the Fermi equation...

[It doesn't come easy]

Considering the statistically unlikely percentage of planetary orbits that would naturally line up so that the planet would transit its sun from our point of view, planets must be pretty much common as dust. Either that or God was nice enough to line them up so it's easy for us to find them (possible, I hear God is a very nice person)...

Re:Pegs that variable in the Fermi equation...

[2names]

"God was nice enough to line them up so it's easy for us to find them"

Um, you do know that the Universe is flat, right? Just like Earth. :)

Re:Pegs that variable in the Fermi equation...

[Stephan202]

Aren't you referring to the Drake equation?

Re:Pegs that variable in the Fermi equation...

[jobsagoodun]

This is the whole argument that Stephen Hawkins uses to "believe in God."

Quite the opposite actually...

"You cannot prove that I exist", says God, "For Proof denies faith, and without faith I am nothing!"
"Ah", says man, "But the planets lining up nicely like that so that we can see them is a dead give away isn't it. It proves you exist, and therefore by your own logic you don't. QED"
"Oh bugger I hadn't thought of that" says God and disappears in a puff of logic.


Sorry Mr Adams.

Re:Pegs that variable in the Fermi equation...

[Rei]

possible, I hear God is a very nice person

Really? Then why'd he go and bury all of those dinosaur bones and radioisotopes to test our faith?

Re:Pegs that variable in the Fermi equation...

[Anonymous Coward]

This is the whole argument that Stephen Hawkins uses to "believe in God." Basically that things like this don't just happen randomly.

Which is pretty much the reason for the existence of all gods throughout history; to provide an explanation for something that was otherwise unfathomable. And of course once a thing becomes "fathomed" that particular god is no longer needed, and disappears.

I also might preemptively mention that "this is different, and also he's a really really smart guy way smarter than you wiseguy" is not a compelling argument.

Re:Pegs that variable in the Fermi equation...

[elrous0]

Yeah, now the only question is "Which God?"

Will we ever find Earth 2.0 candidates?

[2names]

Yes, as long as we don't kill ourselves first.

Re:Will we ever find Earth 2.0 candidates?

[ls -la]

Yes, as long as we don't kill ourselves first. Better hurry up and colonize other planets.

Re:Will we ever find Earth 2.0 candidates?

[omeomi]

Will we ever find Earth 2.0 candidates?"

I certainly hope it contains the same easy-to use ergonomic AJAX functionality as Web 2.0...I hate having to reload an entire Earth page every time I want to do something...

Ummm....It's The Wobble Method That's Tops

[cybrpnk2]

Read the article. Discovering planets via the transit method (eclipse dimming of the star) is rare. Around 80% are instead discovered using the so called wobble method, which measures changes in starlight doppler shift.

Yes

[nizo]

Will we ever find Earth 2.0 candidates?

Of course; space is big and there are bound to be tons of great planets out there. I just hope there is no one already living on our soon to be discovered new colony planet so we can move in quicker.

Re:Yes

[StikyPad]

I just hope there is no one already living on our soon to be discovered new colony planet so we can move in quicker.

Barring that, hopefully we can develop some kickass motherships and tripod walkers.

Bowman 2.0

[Rob T Firefly]

All these World 2.0s are yours except Europa 2.0. Attempt no landings there.

Re:Bowman 2.0

[rucs_hack]

I'm sorry, I can't moderate that for you Dave...

Will we ever find Earth 2.0 candidates?

[jhouserizer]

Will we ever find Earth 2.0 candidates? I'm sure we will. And when we do, I have a number of candidates for who should be sent there.

perhaps not so lucky

[goombah99]

Considering the statistically unlikely percentage of planetary orbits that would naturally line up so that the planet would transit its sun from our point of view, planets must be pretty much common as dust. Either that or God was nice enough to line them up so it's easy for us to find them (possible, I hear God is a very nice person)... Maybe not so lucky. Most of the planets in our solar system (not all) have their rotational axes mostly parallel to their orbital axis. I assume there's some reason for that, perhaps simply if they are spun off of the sun then they acquire it's angular momentum. Or like the moon where tidal forces lock the orbit. In any case then, the next question is if the solar systems in our galaxy mainly orbit in the plane of the galaxies rotation. I'd assume so.

Given all that then it's not too surprising that there be a preference for this favorable occultation geometry.

Finally I note that we are not really interested in planets that don't rotate in their orbital plane since otherwise they'd be roastingly hot on one side and freezing on the other.

Re:perhaps not so lucky

[Black Perl]

Finally I note that we are not really interested in planets that don't rotate in their orbital plane since otherwise they'd be roastingly hot on one side and freezing on the other.

Yes, but wouldn't there be a certain ring that is exactly 70 degrees? Also, you'd have an endless supply of geothermal energy. The hot-as-lava side could double as an incinerator--no trash problems. Obviously terraforming would be impossible but I'd think you could establish a permanent colony there.

Re:perhaps not so lucky

[Chris Burke]

Yes, but wouldn't there be a certain ring that is exactly 70 degrees?

I'm no expert, but I'd be willing to bet that what you'd really get is a ring that fluctuates violently between the hot and cold extremes of the two sides of the planet and is constantly bombarded by gigantic storms. I mean we're basically talking about a permanent clash between hot and cold weather fronts.

Huge temperature deltas do not result in nice smooth gradients between them.

Re:perhaps not so lucky

[jae471]

It should be noted that out the Sun's axis of rotation (and that of the major planets) is NOT with the galactic plane. We can see them, but they can't see us...

Re:perhaps not so lucky

[mp3phish]

Your statement seems misleading but it may just be incomplete (IMO).

"Finally I note that we are not really interested in planets that don't rotate in their orbital plane since otherwise they'd be roastingly hot on one side and freezing on the other."

The rotation of the planet has nothing to do with the detection of planets in this method, only the orbit determines the ability to detect it. So while some planets may or may not be rotating on the correct axis to support multiple seasons, it isn't accounted for in this type of study because they can't detect this with the transient method.

Also, there are actually a large variation of planes that can be detected with this method. Imagine our solar system as a disk. Then imaging looking at it from the top view. This view does not allow the planet detection using the transient method. However, angle your view down until you can see just one of the planets cross over the sun. From this angle on, and twisted up to 360 degrees, is where this transient method works. So actually, there are many planes of orbit which can be used to detect planets with this method. And assuming that a percentage of these planets are within the habitable distance from their star, and that a percentage of these rotate on a reasonable axis, then they could contain life. But nothing in these studies is determining that any of this is the case. Right now they are just looking for ANY planets. so we can detect extrasolar planets even if their orbital planes are perpendicular to the galactic disk, so long as they are close to parallel to our viewing line of site. With this in mind, you can imagine that if you can view stars in our galaxy from 360 degrees around our planet, that we would be able to detect every orbital plane angle available in the galaxy, depending on which direction we are looking from the earth. So while we can't see all of them, we can see a very large subset of them with this method.

Also, the reason that all the planets in the solar system follow close to same typical plane of orbit is because of the way solar systems form. They start as a gaseous body collapsing. As the rotation of the gas nears closer and closer to the center of the nebula, the rotational inertia causes the forming of a disk due to inertia. The same thing happens to drag car tires when they spin fast (they turn more disk-like). From this disk-like nebula the planets form. The center typically ends up with something larger than a gas giant (the sun, or a couple of suns) and the other planets turn into gas giants (Jupiter) or solid planets (i forgot the name, but they gain gravitational pull and pull in particles from the nebular disk)

So this is why the planets are all in one plane of orbit. If all star systems are formed in this general method (something that is assumed) then it is fairly easy to say that they should all be in a single plane. But each system does not necessarily have to be in the same plane relative to each other just because they are in the same galaxy. Each nebula forms independently and collapses typically from an outside force, but not necessarily on the same rotational plane.

Also, the planets have their own disks associated with them. The moons and rings of Uranus and Saturn and Jupiter follow different planes. They don't necessarily need to follow the same plane as the solar system. This is because each of those planets also formed independently of each other. The spin of those depends on the angular momentum of the local mass as it formed, which would be different than the parent nebular disk especially when you take into account collisions of forming bodies. The same could be said to happen on the galaxy level, if you compare the galaxy formation to solar system formation.

These are just my points of view of what I have studied. Many people will have different points of view formed from the same observations.

Re:perhaps not so lucky

[Hays]

In any case then, the next question is if the solar systems in our galaxy mainly orbit in the plane of the galaxies rotation. I'd assume so.

They don't. See http://curious.astro.cornell.edu/question.php?numb er=633

Our own Solar system is not at all aligned with the galaxy. If it were, the milky way would appear more east-west in the night sky, especially during the equinox.

Re:perhaps not so lucky

[The_Wilschon]

Not so. The plane of the ecliptic and the galactic equator are offset from one another by about 62 degrees. [1] So it would appear that there is probably wide variation in the tilt of the ecliptic planes of other stellar systems.

Or, a naive argument from astrophysics (IANA astrophysicist, although I am a physicist): Perhaps the disk of a new-formed star is typically rather thin (in the direction perpendicular to the ecliptic). Then material undergoing gravitational accretion to form planets would all come from essentially one plane, so the angular momentum would be perpendicular to that plane (Newtonian physics: take any number of masses with positions and velocities all solely in one plane. The angular momentum about any point will be perpendicular to that plane). The galaxy, on the other hand, is quite thick, even out here in the fringes. The nebulae that we can see are not planar, and are not even larger in the galactic plane or anything. They are fairly isotropic. So, as a nebula condenses to become a star, the material comes from all directions and has velocities going in all directions. The angular momentum could be all over the place.

So, if there isn't anything wrong with this naive argument (although there quite likely is, even if it doesn't invalidate the conclusion), then we should expect that stars should have ecliptics lying at all kinds of angles to the galactic equatorial plane. The angle of our own ecliptic is a single data point which would seem to support this notion.


We probably are actually quite interested in planets with rotational axes lying not perpendicular to their ecliptics. Not as Earth 2.0, but for scientific study, they should be rather interesting. How do they form? Are they typically captured rogue planets? Is there such a thing as a rogue planet? Or do they merely form from thicker solar disks? Or, did Aliens (TM) put them there as signals to us for when we become a mature enough species to understand them? :)

I'm not sure how serious you're being

[benhocking]

However, they do plan on looking for signs of molecular oxygen in the atmospheres of some of these planets. Molecular oxygen is chemically unstable, so its presence is usually considered to be an excellent indicator of life. Not perfect, as it might not be necessary or sufficient, but it's the best method we have right now for detecting M-class planets.

Version

[Bromskloss]

Will we ever find Earth 2.0 candidates?

How about making the current one stable first?

Re:Version

[Anonymous Coward]

>How about making the current one stable first?

The current one is fine. It was here before us, and will be here long after us.

How about we kick condesending butts like your's into the sun?

Extra Solar

[Punko]

Every time I see "Extra solar planet" I envision a planet with more than one sun.
I mean "extra salt" = more salt, right ?

so we can ...

[polar red]

Will we ever find Earth 2.0 candidates? so we can ...

• continue to wreck this one?
• declare them part of the axis of evil?
• export our garbage there ?
• ... ?

That's not how the number system works

[benhocking]

Everyone knows it's the even-numbered versions that are stable...

now that we can find them

[niloroth]

What are we going to do about getting there? Unless we can figure out some way to travel faster than the speed of light, i doubt any human will ever step foot on a planet outside our solar system. I think it far more likely that we will have to terraform one of the ones near us, and even then, we seem to messing this one up way faster than we could even start that process. I think hawkins may be right, 1000 years at most left for us. Although that really may have been a bit optimistic.

Re:now that we can find them

[jshriverWVU]

Your view seems 1/2 true. No person in a single lifetime can make the journey. The goal would be to create a ship large enough to sustain many families, and the resulting offspring of a couple generations would make it.

Re:now that we can find them

[StikyPad]

the resulting offspring of a couple generations would make it.

Aside from the lifetimes of "Are we there yet?", you know the offspring would just take the fact that they're on an interstellar voyage for granted, and they wouldn't even appreciate the arrival. "This is the planet my great grandfather wanted to visit," they'd say. "Let's check out Earth."

I cannot be alone

[blindd0t]

...when I say if it is actually called "Earth 2.0" that I would seek Kevorkian's "assistance." (Joking, of course.) The moniker is used way too much! Instead, I feel we should call the planet "Godzilla" so it would be entertaining to hear people scream its name in excitement upon viewing it for the first time.

Updated stats

[EvilGrin5000]

The link to Space.com for the 'most interesting extra-solar planets' has a top 10 list with all the new updated data. The article from the summary said that the fastest planet's orbit around its sun is 1.2 days, where instead the top-10 list shows a recently discovered planet with an orbit of just 10 hours! There is a link that leads to this page http://www.space.com/scienceastronomy/061004_fast_ planets.html that talks about 'fast planets' and shows the new data.

I recommend going to the top-10 list found at http://www.space.com/scienceastronomy/extrasolar_p lanets.html just click at the bottom link where it says "Number 10: The First" and off you go! It's actually a really nifty countdown :)

Enjoy!

Space.com... the worst website in the universe?

[sean.peters]

God, what a mess the "Top 10 Exoplanets" site is! Bright orange background that is absolutely physically painful to look at, requires 10 click-throughs to read the whole article (when each page has about a paragraph of text), the text itself is in little iframes that require you to scroll to get past the first few sentences - and don't get me started about the content (what little there is). If you haven't visited it... don't.

Re:Earth 2.0?

[Loke the Dog]

Its a joke based on the hype around "web 2.0", which everyone knows sounds stupid. Now, laugh.

Looking for Earth 2.0?

[clovis]

Why do you assume that we are not already on Earth 2.0?

Well...

[Greyfox]

We'd have to work around that nasty speed of light thing first. I seem to recall that it'd take about 450,000 years to reach the one we found that has water, which is 20 light years from here. If that proves impossible then those planets will be forever out of our reach.

Re:Well...

[cswiger]

We'd have to work around that nasty speed of light thing first.

True, that's a big problem compared with the popular "space opera" notion we've gotten from Star Wars, Star Trek, and so forth. But if we could get a vessel up to 10% of light speed, we could get to Epsilon Eridani in about 107 years, which isn't an impossibly long timeframe.

Of course, the fastest we've gotten any space craft going is about 0.02% of light speed (Helios 2 @ 241,350 km/h), if I've done my math right, but that took advantage of the solar gravity well to accelerate into a tighter orbit, rather than fighting out of it enough to reach escape velocity with respect to Sol. The Voyager series craft, for contrast, have managed to reach system escape velocity, but only retained a velocity of about 0.003% of c (62,100 km/h). We'd need to get them going some thousand times faster than what we've done so far to make interstellar voyages to the closer stars doable within something vaguely close to a human lifespan.

Standard SF options

[geek2k5]

While we don't have the tech in place to make the trip now, we do have ideas of what could be done. We just need to get some cheap Earth to Orbit launch facilities in place so we can start research and development of the tech needed. (Rutan's SpaceShipX ships. Space elevators. Catapult launch from high altitude sites.)

Once we have a lot of people and equipment in space, we could do such things as build generation ships and take the slow route. Whether powered by Sol base lasers, atomic bombs (Orion), ion propulsion, solar sails or other related tech, we can launch something at choice targets without a lot of extra tech. (It would be more of an engineering problem than a science problem.) It will take a long time to get there and the odds of sending people back will be low if it is attempted.

Now with space based research we might be able to come up with variations on the classic FTL drive, making it possible to do such a trip and make it back in a reasonable amount of time. This would require some basic breakthroughs in science, followed by engineering to make the science usable.

At this time those breakthroughs are mostly pipedreams. But in centuries past, things like steam engines, airplanes and spaceships were the same way. While they may seem simple to us, in years gone by they were future technology that needed a lot of research to make it possible.

Re:There are NO extrasolar planets.

[emurphy42]

More precisely, the new definition does not attempt to classify extra-solar bodies as either planets or not-planets. It starts out like this (emphasis mine):

The IAU therefore resolves that "planets" and other bodies in our Solar System, except satellites, be defined into three distinct categories in the following way:

The IAU's working group on extra-solar planets does offer a working definition, subject to change. See Wikipedia for more details. See also rogue planets.