Dozens of Earth-like Planets Found!

[GWiz]

Umm, on the contrary, that's the easy part. We know the star's mass, the orbital period of the planet, and the radius of the planet. That tells us the planet's mass and thus its average density. Calculating a trajectory that takes a spacecraft from the solar system to one of these other stars and enters an orbit around one of these planets would be a relatively simple matter, made only slightly more complicated if the spacecraft can travel fast enough to make it necessary to include relativistic effects.

I can write a MATLAB script to do it on my laptop in about an afternoon of coding and it'd take about 10 milliseconds to compute.

This problem certainly has many hard parts, biggest among them being propulsion and power systems, but figuring out the orbital mechanics and the needed spacecraft trajectories isn't one of them.

What kind of orbit are we talking about for this planet, eliptical, circular? How is the density calculated and is that density before or after an atmosphere or lack thereof is calculated in? What is the intersecting proximity at any given time to any other planets, moons, etc.? Need I go on and on? These planets have NOT been "seen", they have been calculated as being the cause of an effect on a "star" BELIEVED to have "earth sized" planets orbiting said star...

Good luck with that calculation...

I write both fiction and non fiction and I can tell you writing non fiction is a lot more difficult to do well than writing fiction...

[wyly]

and then how do you determine if the planet destination has a magnetic field to protect us from solar radiation?

years or decades in a low G or no G environment like a space craft will make it next to impossible to function on a earth like planet when you arrive...

you could send thousands of probes for a thousand years and not find a suitable planet...

then there are those nasty microbial things we will have zero immunity from, simple diseases such chicken pox and measles killed our indigenous populations in the millions...NASA now sterilizes it's probes so that earth microbes don't infect other potential biospheres in our solar system potentially destroying any life that may be there...I know no one wants to discuss this point because it destroys the travel fantasy dead in it's tracks but that's the reality of it...our simple arrival on a planet and the germs we introduce could destroy the planet or it's germs could(more than likely) destroy us...

Edited February 9, 2011 by wyly

[Wild Bill]

What kind of orbit are we talking about for this planet, eliptical, circular? How is the density calculated and is that density before or after an atmosphere or lack thereof is calculated in? What is the intersecting proximity at any given time to any other planets, moons, etc.? Need I go on and on? These planets have NOT been "seen", they have been calculated as being the cause of an effect on a "star" BELIEVED to have "earth sized" planets orbiting said star...

Good luck with that calculation...

I write both fiction and non fiction and I can tell you writing non fiction is a lot more difficult to do well than writing fiction...

Actually, Mr. Whiz, Bonam doesn't write fiction or non-fiction concerning this stuff. He works for the companies that MAKE this sort of stuff!

Hard, real-world engineering of things that you can reach out and touch RIGHT NOW! Not old stories from 1930's scifi pulp magazines.

He knows whereof he speaks probably better than anyone else on this board about this kind of thing.

This site might be of interest to you. These guys are doing stuff NOW! They are stepping into the void with NASA retiring the shuttles with commercially built craft to reach orbit and the space station. (Considering the only other option is the Russkies and they are intending to charge a FEROCIOUS rip!):

http://www.spacex.com/updates.php

Edited February 9, 2011 by Wild Bill

[Sir Bandelot]

We know the star's mass, the orbital period of the planet, and the radius of the planet. That tells us the planet's mass and thus its average density. Calculating a trajectory that takes a spacecraft from the solar system to one of these other stars and enters an orbit around one of these planets would be a relatively simple matter, made only slightly more complicated if the spacecraft can travel fast enough to make it necessary to include relativistic effects.

They (astronomers) have done some spectroscopy as well, including temperature and chemical composition.

Here is one example-

http://www.eso.org/public/news/eso1002/

[Sir Bandelot]

and then how do you determine if the planet destination has a magnetic field to protect us from solar radiation?

years or decades in a low G or no G environment like a space craft will make it next to impossible to function on a earth like planet when you arrive...

you could send thousands of probes for a thousand years and not find a suitable planet...

then there are those nasty microbial things we will have zero immunity from, simple diseases such chicken pocks and measles killed our indigenous populations in the millions...NASA now sterilizes it's probes so that earth microbes don't infect other potential biospheres in our solar system potentially destroying any life that may be there...I know no one wants to discuss this point because it destroys the travel fantasy dead in it's tracks but that's the reality of it...our simple arrival on a planet and the germs we introduce could destroy the planet or it's germs could(more than likely) destroy us...

Those are problems but they can be solved. For one thing, simple exercise machines. There's no question the human body needs to exert physical force. They would have to spend their days in the on-board gymnasium.

In fact if they were to connect the weight lifting machines to a generator, and use it to help power the space-craft somehow, then they'd be adding to the acceleration of the vehicle. Remember there are little or no external forces of gravity on the craft in deep space, so any force you add is very efficient. There I've just invented another type of propulsion system.

[GWiz]

Actually, Mr. Whiz, Bonam doesn't write fiction or non-fiction concerning this stuff. He works for the companies that MAKE this sort of stuff!

Hard, real-world engineering of things that you can reach out and touch RIGHT NOW! Not old stories from 1930's scifi pulp magazines.

He knows whereof he speaks probably better than anyone else on this board about this kind of thing.

This site might be of interest to you. These guys are doing stuff NOW! They are stepping into the void with NASA retiring the shuttles with commercially built craft to reach orbit and the space station. (Considering the only other option is the Russkies and they are intending to charge a FEROCIOUS rip!):

http://www.spacex.com/updates.php

Bill, I'm well aware of that site and many other sites such as that that I would use in researching BOTH a fiction or non fiction book... A site like that though would have little or no influence on a book regarding anything beyond it's specific scope such as interplanetary or beyond travel...

[Wild Bill]

Bill, I'm well aware of that site and many other sites such as that that I would use in researching BOTH a fiction or non fiction book... A site like that though would have little or no influence on a book regarding anything beyond it's specific scope such as interplanetary or beyond travel...

Well, I thought that "interplanetary or beyond travel" was what we were talking about!

Anyway, I mentioned that site because I do believe Mr. 'Bonam' works for them. Not that that makes him infallible but still, a very qualified opinion.

[GWiz]

Well, I thought that "interplanetary or beyond travel" was what we were talking about!

Anyway, I mentioned that site because I do believe Mr. 'Bonam' works for them. Not that that makes him infallible but still, a very qualified opinion.

It is what we are talking about but that site isn't... Back at'cha...

I'm also aware of Bonam's scienticic "qualifications" and I admire him for it, however, being that I'm an Alien Being, I may have some expertise that he does not...

[Bonam]

Actually, Mr. Whiz, Bonam doesn't write fiction or non-fiction concerning this stuff. He works for the companies that MAKE this sort of stuff!

Hard, real-world engineering of things that you can reach out and touch RIGHT NOW! Not old stories from 1930's scifi pulp magazines.

He knows whereof he speaks probably better than anyone else on this board about this kind of thing.

This site might be of interest to you. These guys are doing stuff NOW! They are stepping into the void with NASA retiring the shuttles with commercially built craft to reach orbit and the space station. (Considering the only other option is the Russkies and they are intending to charge a FEROCIOUS rip!):

http://www.spacex.com/updates.php

Thanks for the compliments...

In this case, the planets are detected by what is known as the transit method. The way this works is that we know the luminosity of the star. When a planet passes between our vantage point and the star, it blocks some of the star's light from reaching us. Based on what % of the light is blocked, we can figure out the planet's radius relative to the star. For example, if a star's luminosity drops by 1%, we know that the planet's area is 1% of the star's area (area as in cross-sectional area), which means its radius would be 10% of the star (in practice, the planets are usually much smaller than that).

We also know how fast the planet is traveling because we measure what period of time the star dims for. For example, if the star has a diameter of 1 million km, and it dims for say 5 hour due to a planet passing in front of it, then we know the planet has an orbital velocity of 55.6 km/s.

So from direct measurement we know the radius and the orbital speed of the planet. Based on the formula for orbital speed, which depends on the mass of both the star and the planet, we can get a result for the planet's mass and its oribtal radius. Then, since we know both the planet's mass and its radius, we can easily get its density (density = mass/volume).

Now, as for measuring the eccentricity of the orbit, that is a bit more difficult, but still doable. A planet traveling in an elliptical orbit varies in speed throughout its orbit. When it is closer to the star it travels more quickly, and when it is farther from the star it travels slower (Kepler's 2nd law). When we see a planet transit in front of the star, there is a period of time when the planet is first beginning to come in front of the star but isn't yet fully in front of it, as in this image here:

http://epoxi.umd.edu/3gallery/graphics/Planetary_Eclipse-lg.jpg

So there is a gradual drop in the measured luminosity of the star at time 2 on that graph, and a corresponding return to the normal luminosity when the planet leaves from in front of the star. If the orbit is perfectly circular, then the time it takes to go from full brightness to reduced brightness, and the time it takes to go back, would be precisely equal. But if the orbit is elliptical, then the planet will be traveling faster at one of these points than at the other, and there would be a time difference. Based on how big this time difference is, we can determine just how elliptical the orbit is. Obviously, as with all measurements, there is an error range around the resulting values.

As for other orbits in the star system... the transit method allow us to detect some of the planets, but perhaps not all of them (if, for example, the planets in the star system are orbiting in different planes). Usually, however, we detect most of them, because if the orbital plane is visible from our vantage point, then that is the same orbital plane for all the planets, and they will all appear to transit in front of the star. But, of course, there are exceptions which orbit out of plane, like Pluto in our own solar system. Such planets can be detected by other means, however, such as the gravitational wobble technique, and, indeed, studying planetary systems detected by Kepler using the transit method with other techniques will be a priority of exoplanet scientists worldwide throughout the coming years.

Edited February 9, 2011 by Bonam

[Bonam]

and then how do you determine if the planet destination has a magnetic field to protect us from solar radiation?

Actually, that is relatively straighforward. Before we send any probes to any planets, we would study them spectroscopically, that is, find the emission lines from the planet. Obviously, we would be looking for the presence of oxygen in the atmosphere and water on the surface, and these both have distinct emission lines. But, another advantage of spectroscopy is the Zeeman effect. Due to this effect, in the presence of a magnetic field, the spectral lines "split" into multiple lines. So, where we would normally see just one oxygen emission line, if there was a magnetic field, we would see (for example) three spectral lines. The separation between these lines (as in, in picometers of wavelength on the EM spectrum) tells you the strength of the magnetic field, as described on the page I linked.

So, as soon as we can take exoplanetary spectra (there are already a few proposals to launch observatory spacecraft with this capability), we will be able to tell not only the presence of the right gases in exoplanetary atmospheres, but also the presence and strength of magnetic fields.

We already use this method to measure the strengths of magnetic fields around stars, neutron stars, and black holes, and extending the methodology to planets just means using a more precise instrument (or not: for example, Jupiter's magnetic field is actually stronger than the Sun's).

years or decades in a low G or no G environment like a space craft will make it next to impossible to function on a earth like planet when you arrive...

For a spacecraft that is to undertake an interstellar journey, it would be a trivial matter to give it an axial spin which would produce centrifugal force equivalent to 1g within a habitable area of the craft.

you could send thousands of probes for a thousand years and not find a suitable planet...

That's why you study things with telescopes from our own solar system first? The Kepler telescope is the first of these, but other missions which can give us more precise data are planned.

then there are those nasty microbial things we will have zero immunity from, simple diseases such chicken pocks and measles killed our indigenous populations in the millions...NASA now sterilizes it's probes so that earth microbes don't infect other potential biospheres in our solar system potentially destroying any life that may be there...I know no one wants to discuss this point because it destroys the travel fantasy dead in it's tracks but that's the reality of it...our simple arrival on a planet and the germs we introduce could destroy the planet or it's germs could(more than likely) destroy us...

The biology that would have evolved on any other planet would be drastically different from our own, as it would have evolved independently. Diseases can affect us because they have evolved over billions of years to be able to interact with the biologies of the animals and plants in their environment. On another planet, any living organisms would likely not even have anything chemically similar to our DNA/RNA. There simply would be no basis for them to interact with each other. It is the same thing as what prevents certain diseases on Earth from jumping between species... but here there is a lot of similarity between animals, and a slight mutation can allow the disease to transition. On another planet, we'd have no similarities with the native lifeforms at all, and it would likely take millions of years of cohabitation before natural evolution would allow any alien germs to affect human beings.

Edited February 9, 2011 by Bonam

[Bonam]

Just to sum up... sending any kind of spacecraft, especially a manned one, to a planet in another system would obviously be very difficult. There are many problems that would have to be solved, both engineering problems to be resolved and additional scientific data that would be needed. But, none of these problems are unsolvable, they are all within the scope of human ingenuity, and conceptual solutions to all these problems can already be described in great detail today. The primary limitations, as of today, that prevent us from launching an interstellar mission are:

1) Any interstellar mission would need a very very large mass, and putting such a mass into space (from Earth) in the first place would be prohibitively expensive. This can be resolved in the future if we develop cheaper access to space from Earth or can produce and launch materials from lower gravity bodies in the solar system (for example the Moon, Mars, comets, etc).

2) The opposition to and restrictions on the use of nuclear power and nuclear weapons in space. Any interstellar mission would have to be nuclear powered, and nuclear propulsion would be a necessity as well.

Existing designs for robotic interstellar probes based on presently available technology that can travel a few light years in a few decades have initial masses on the order of ~10,000 tons and use thousands of miniature nuclear bombs for propulsion. The present launch costs for this mass of material are on the order of ~$40 billion. As well, development and production would also cost tens of billions, and probably it would total to well over $100 billion. But, that is also about the cost of the international space station program (estimated at $150-$250 billion USD).

If we wanted to put in the same level of effort and money as went into the space station, we could design, build, and launch an unmanned interstellar probe within ~20 years and have it arrive at (for example) our nearest neighboring star system (Alpha-Beta-Proxima Centauri) about 50 years after launch, with a peak speed around ~0.1c using nuclear pulse propulsion.

Within a few decades, when we have space-rated fusion system, the required masses will drop significantly and the required travel times will drop slightly. Note that even if fusion research for power production on Earth keeps on taking longer and longer as it has been throughout the last 50 years, the level of development already achieved in fusion is all that is necessary for use in space. On Earth, you want continuous (steady state) net energy production to build a power plant, but in space, you can settle for short bursts of high power that are supplemented by another energy source (a fission system), and existing fusion research has already achieved this.

Edited February 9, 2011 by Bonam

[Bonam]

double post

Edited February 9, 2011 by Bonam

[GWiz]

Actually, that is relatively straighforward. Before we send any probes to any planets, we would study them spectroscopically, that is, find the emission lines from the planet. Obviously, we would be looking for the presence of oxygen in the atmosphere and water on the surface, and these both have distinct emission lines. But, another advantage of spectroscopy is the Zeeman effect. Due to this effect, in the presence of a magnetic field, the spectral lines "split" into multiple lines. So, where we would normally see just one oxygen emission line, if there was a magnetic field, we would see (for example) three spectral lines. The separation between these lines (as in, in picometers of wavelength on the EM spectrum) tells you the strength of the magnetic field, as described on the page I linked.

So, as soon as we can take exoplanetary spectra (there are already a few proposals to launch observatory spacecraft with this capability), we will be able to tell not only the presence of the right gases in exoplanetary atmospheres, but also the presence and strength of magnetic fields.

We already use this method to measure the strengths of magnetic fields around stars, neutron stars, and black holes, and extending the methodology to planets just means using a more precise instrument (or not: for example, Jupiter's magnetic field is actually stronger than the Sun's).

For a spacecraft that is to undertake an interstellar journey, it would be a trivial matter to give it an axial spin which would produce centrifugal force equivalent to 1g within a habitable area of the craft.

That's why you study things with telescopes from our own solar system first? The Kepler telescope is the first of these, but other missions which can give us more precise data are planned.

The biology that would have evolved on any other planet would be drastically different from our own, as it would have evolved independently. Diseases can affect us because they have evolved over billions of years to be able to interact with the biologies of the animals and plants in their environment. On another planet, any living organisms would likely not even have anything chemically similar to our DNA/RNA. There simply would be no basis for them to interact with each other. It is the same thing as what prevents certain diseases on Earth from jumping between species... but here there is a lot of similarity between animals, and a slight mutation can allow the disease to transition. On another planet, we'd have no similarities with the native lifeforms at all, and it would likely take millions of years of cohabitation before natural evolution would allow any alien germs to affect human beings.

The Rings of Jupiter

Jupiter has a series of rings circling it! Unlike Saturn's rings, which are clearly visible from Earth even through small telescopes, Jupiter's rings are very difficult to see. So difficult, in fact, that they weren't discovered until a few years ago. Jupiter's rings were first found by the Voyager 1 spacecraft in 1979.

There are three parts to Jupiter's rings. The innermost, cloud-like ring is called the Halo Ring. The next one out is the Main Ring, which is quite narrow and thin. Beyond the Main Ring is the wispy, nearly transparent Gossamer Ring. As shown in the diagram, the Gossamer Ring has two parts: the Amalthea Gossamer Ring (closer to Jupiter) and the Thebe Gossamer Ring.

Saturn's rings are mostly made of ice. Jupiter's rings are different - they are very dark and difficult to see. They are made up of small bits of dust. The Galileo spacecraft helped us discover where that dust comes from. Meteors striking the surface of Jupiter's small, inner moons kick up dust which then goes into orbit around Jupiter, forming the rings.

http://www.windows2universe.org/jupiter/rings.html

I'm confident that as a scientist you will see the relevance of this post...

How would one determine the cycle of an eliptical orbit based even on a complete single years observation... Since all measurements and hyposthesis are based on a relationship to an observable star is one observing it at it's closest or farthest point in relation to said star... Does this closeness vary on a cyclical basis as do all the planets in our own solar system... Being that we are looking at a variety of stars that encompass these "earth sized" (as opposed to earth like) planets, and as far as I know (I stand to be corrected) none of them are the same as our sun what variables does that add to the composition, orbits, etc. in the calculations pertaining to any single "planet" referrenced in this thread?

What would be your best estimate of the TIME it would take a probe, using the best and latest technology available today, to physically reach the nearest of these newly discovered planets were that probe to be launched this year?

One other point I'd like to make is that before speculating too much about travelling to these newly found Planets everyons should really read the "source material" about them - http://www.nasa.gov/mission_pages/kepler/news/new_planetary_system.html - presented in easy to understand "layman's terms"...

- All of the planets orbiting Kepler-11, a yellow dwarf star, are larger than Earth, with the largest ones being comparable in size to Uranus and Neptune. The innermost planet, Kepler-11b, is ten times closer to its star than Earth is to the sun. Moving outwards, the other planets are Kepler-11c, Kepler-11d, Kepler-11e, Kepler-11f, and the outermost planet, Kepler-11g, which is twice as close to its star than Earth is to the sun.

"The five inner planets are all closer to their star than any planet is to our sun and the sixth planet is still fairly close," said Lissauer.

If placed in our solar system, Kepler-11g would orbit between Mercury and Venus, and the other five planets would orbit between Mercury and our sun. The orbits of the five inner planets in the Kepler-11 planetary system are much closer together than any of the planets in our solar system. The inner five exoplanets have orbital periods between 10 and 47 days around the dwarf star, while Kepler-11g has a period of 118 days. -

[GWiz]

Sorry Bonam, I got busy with something else and took some time to post my previous post thereby cross posting with your latest post...

err, it's complicated...

Edited February 9, 2011 by GWiz