Posted on 01/09/2018 11:12:12 AM PST by Red Badger
This artist's concept depicts a planetary system. Credit: NASA/JPL-Caltech
An international research team led by Université de Montréal astrophysicist Lauren Weiss has discovered that exoplanets orbiting the same star tend to have similar sizes and a regular orbital spacing. This pattern, revealed by new W. M. Keck Observatory observations of planetary systems discovered by the Kepler Telescope, could suggest that most planetary systems have a different formation history than the solar system.
Thanks in large part to the NASA Kepler Telescope, launched in 2009, many thousands of exoplanets are now known. This large sample allows researchers to not only study individual systems, but also to draw conclusions on planetary systems in general. Dr. Weiss is part of the California Kepler Survey team, which used the W. M. Keck Observatory on Maunakea in Hawaii, to obtain high-resolution spectra of 1305 stars hosting 2025 transiting planets originally discovered by Kepler. From these spectra, they measured precise sizes of the stars and their planets.
In this new analysis led by Weiss and published in The Astronomical Journal, the team focused on 909 planets belonging to 355 multi-planet systems. These planets are mostly located between 1,000 and 4,000 light-years away from Earth. Using a statistical analysis, the team found two surprising patterns. They found that exoplanets tend to be the same sizes as their neighbors. If one planet is small, the next planet around that same star is very likely to be small as well, and if one planet is big, the next is likely to be big. They also found that planets orbiting the same star tend to have a regular orbital spacing.
"The planets in a system tend to be the same size and regularly spaced, like peas in a pod. These patterns would not occur if the planet sizes or spacings were drawn at random." explains Weiss.
The similar sizes and orbital spacing of planets have implications for how most planetary systems form. In classic planet formation theory, planets form in the protoplanetary disk that surrounds a newly formed star. The planets might form in compact configurations with similar sizes and a regular orbital spacing, in a manner similar to the newly observed pattern in exoplanetary systems. However, in our solar system, the inner planets have surprisingly large spacing and diverse sizes. Abundant evidence in the solar system suggests that Jupiter and Saturn disrupted our system's early structure, resulting in the four widely-spaced terrestrial planets we have today. That planets in most systems are still similarly sized and regularly spaced suggests that perhaps they have been mostly undisturbed since their formation.
To test that hypothesis, Weiss is conducting a new study at the Keck Observatory to search for Jupiter analogs around Kepler's multi-planet systems. The planetary systems studied by Weiss and her team have multiple planets quite close to their star. Because of the limited duration of the Kepler Mission, little is known about what kind of planets, if any, exist at larger orbital distances around these systems. They hope to test how the presence or absence of Jupiter-like planets at large orbital distances relate to patterns in the inner planetary systems.
Regardless of their outer populations, the similarity of planets in the inner regions of extrasolar systems requires an explanation. If the deciding factor for planet sizes can be identified, it might help determine which stars are likely to have terrestrial planets that are suitable for life.
The article "The California-Kepler Survey V. Peas in a Pod: Planets in a Kepler Multi-planet System are Similar in Size and Regularly Spaced" is published in The Astronomical Journal.
Explore further: Discovery of new planet reveals distant solar system to rival our own
Journal reference: Astronomical Journal
Johann Bode, please pick up the white courtesy phone.
Good stuff.
Why him?....................
“Planets around other stars are like peas in a pod”
Does this mean ALL planets, or SOME planets? Since it doesn’t say, it is a useless headline.
Seriously, now. Astronomers haven’t observed even a small fraction of all the stars that have planets. Drawing this conclusion is not warranted.
And/or indicating that no two stellar systems are exactly alike.
Heh. Beat me to it.
Agreed.
Seems like we can only detect large planetary objects right now — question: is our technology capable of detecting a solar system like ours? That would include smaller objects like Venus, etc. and the Earth.
Well - depending on what the hypothesis stated they may have been able to select a sample that would be sufficient to predict.
It could still be invalidated with a larger sample, but my guess is they stated their prediction and then sampled a large set to see if that prediction held.
Perfectly reasonable from a scientific point of view.
I think most likely what they are stated in their thesis is that the ‘majority’ are like this since we already know our solar system is not. The further study they mention is to see if systems with both large/small planets exhibit the same pattern ours does. I’m guessing where this is leading is trying to prove that there was a disruption in our system that led to the astroid belt, earth-moon separation, and elusive phantom planet in odd orbit that is continually being discussed.
https://en.wikipedia.org/wiki/Titius%E2%80%93Bode_law
“The Titius–Bode law (sometimes termed just Bode’s law) is a hypothesis that the bodies in some orbital systems, including the Sun’s, orbit at semi-major axes in a function of planetary sequence. The formula suggests that, extending outward, each planet would be approximately twice as far from the Sun as the one before. The hypothesis correctly anticipated the orbits of Ceres (in the asteroid belt) and Uranus, but failed as a predictor of Neptune’s orbit and has eventually been superseded as a theory of solar system formation. It is named for Johann Daniel Titius and Johann Elert Bode.”
If it can’t see the planets far out yet at Jovian distances (20-100 year orbits), then all they are seeing IS the inner rocky worlds. And Earth and Venus are similar in size.
This doesn’t disprove the theoretical model that outer planets are gas giants with long orbits.
The Thunderbolts Project posits an electrical universe. They have a YouTube channel and website (Thunderbolts.info). One theory advanced was that our present solar system resulted from a prior solar-jovian system capturing a saturnian brown dwarf system.
Keck.
This pattern, revealed by new W. M. Keck Observatory observations of planetary systems discovered by the Kepler Telescope, could suggest that most planetary systems have a different formation history than the solar system.
...
I keep trying to convince people that we are rare and special.
Considering that there are trillions of galaxies, I would expect some would have stars much like our sun, surrounded by several planets much like Earth.
No planet is inhabited but ours, but I believe that The LORD has vast amounts of them out there that will be inhabited as billions and billions of years on into infinity. of increased population needs them. They will all be seeded from the earth. Edens revisited, without the wrong choice concerning sin. Praise The LORD!!!
PBS had a show about the Hubble space telescope.
Here are some images of proto solar systems in Orion Nebula
http://burro.case.edu/Academics/Astr221/SolarSys/Formation/OrionProplyds.jpg
http://hubblesite.org/hubble_discoveries/breakthroughs/planetary
They also took a photo of a small area of space, the diameter of a soda straw and found approx 10,000 galaxies with each containing 100 billion stars more or less.
A search at google comes up with the total amount of stars was something like 10 trillion galaxies in the universe and 1,000,000,000,000,000,000,000,000 stars or a “1” with 24 zeros after it. So lots of Star Trek episodes.
The universe is also expanding.
So to sum up we are but a drop on a microscope slide spreading out in some scientists lab. The galaxies are like protozoa.
We are but an atom of hydrogen in the ocean of H2O................................
Psalm 147:4
He telleth the number of the stars; he calleth them all by their names.
I would have to agree with you that they are leaping to conclusions a bit early in the game.
Of course when the only system we had to study was our own they leaped to conclusions there too so they are experienced leapers. :)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
