All Questions
Tagged with exoplanets planets
33 questions
78
votes
6
answers
10k
views
How can we see planets thousands of light years away but don't know if there are more planets in the solar system?
That is basically my question, it arose when I saw an article (here is the scientific paper, which should be free to read) saying two Caltech scientists might have found the 9th planet of the solar ...
- 1,768
10
votes
2
answers
2k
views
How can a gas giant be about the same size but six times more massive than Jupiter?
I've just read this article: http://www.sci-news.com/astronomy/science-kepler-432b-new-super-jupiter-exoplanet-02490.html
And I wondered how this could be possible?
Maybe it's because this gas giant ...
- 1,643
8
votes
3
answers
359
views
Is a rogue 'exoplanet' classed as a exoplanet?
Given that the term planet strictly (according to the IAU) refers to a body around the sun, rogue planets can't be called that, so I assume they must be called rogue exoplanets?
But do they even ...
- 6,987
8
votes
1
answer
4k
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What is the percentage of stars with planetary systems
We have discovered quite a number of exoplanets to date. The Kepler spacecraft has examined 150,000 stars and found 1,059 exoplanets.
We know that Kepler, as well as all other exoplanet searches to ...
- 11.2k
7
votes
2
answers
510
views
Earliest terrestrial planet?
If I've understood correctly, the heavier elements needed for terrestrial planets such as iron can only form in supernova.
If that is indeed true, how long since the beginning of the universe would ...
- 692
7
votes
0
answers
113
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Are there certain alignments in planetary orbits that create interesting effects in the moons or planets? [closed]
We have some interesting examples such as Mercury's perihelion
The planet Mercury is especially susceptible to Jupiter's influence
because of a small celestial coincidence: Mercury's perihelion, ...
- 3,662
6
votes
2
answers
1k
views
How does rogue planet PSO J318.5-22 stay 800ºC?
According to this article, the rogue planet (meaning a planet which does not orbit a star) PSO J318.5-22 has a surface temperature of 800ºC and weather that features molten iron rain. Without a star ...
- 738
4
votes
2
answers
227
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Is it possible that only one hemisphere of a planet has an atmosphere?
Suppose there is a tidally locked planet orbiting a star. The planet's surface consists of a global ocean, that is, liquid water. At the inner hemisphere the temperature is so high that the water is ...
- 11.3k
4
votes
2
answers
208
views
Are there planets orbiting something else than a star?
Exoplanet is a planet that orbits a star different from our Sun.
Are there any planets (that we know of) which orbit something else? (Like different giant planet or black hole or maybe neutron star.)
- 269
4
votes
1
answer
297
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What would be the color of a deep, pure and vast liquid $\rm CO_2$ ocean if viewed from space (ignoring the atmosphere's influence)?
So far I had no luck trying to find the visible absorption spectrum of $\rm CO_2$ anywhere, all I get is the far infrared absorption spectrum and stuff like that.
If you just search "what color ...
- 43
4
votes
1
answer
536
views
What day/night cycles, climate and seasons would experience Alpha Centauri Bb inhabitants?
Alpha Centauri Bb is an exoplanet orbiting Alpha Centauri B. It is asserted that given the close distance to the star the planet should be tidally locked.
The orbiting period of the planet is about ...
- 11.3k
3
votes
1
answer
2k
views
How is the stellar flux for exoplanets calculated?
I have noticed that in many Wikipedia articles, the stellar flux received by each planet is stated. I tried to calculate this stellar flux from the given data, but the results didn't seem to be ...
- 3,934
3
votes
1
answer
87
views
Have we observed sufficient extra-solar planetary systems to establish a planetary distribution pattern? [duplicate]
From Kepler And Extra-Solar Planetary Observations
As of January 2015, Kepler and its follow-up observations had found 1,013 confirmed exoplanets in about 440 stellar systems, along with a further ...
user81619
2
votes
2
answers
157
views
For a planet which has a temperature gradient, hot in the center and cooler on the surface, why do we get absorption lines?
For a planet which has a temperature gradient, hot in the center and cooler on the surface, why do we see absorption lines?
Similarly, why do we see emission lines if the planet is hot on the ...
- 1,015
2
votes
2
answers
184
views
Is drinking water an important feature for finding habitable exoplanets? Has it been found?
We need drinking water to live on other planets. Has drinking water been found on other exoplanets? Is drinking water an important feature for finding habitable exoplanets?
I want to (self) study in ...
- 376
2
votes
1
answer
219
views
Calculating the size of exoplanets with moons
When astronomers detect an exoplanet using its transit and calculate its size to be, say twice the earths size, do they have any way of knowing that its actually not a slightly smaller planet with a ...
- 303
2
votes
0
answers
102
views
What orbit does a planet have to have to be a planet? [closed]
Other questions have dealt with where you could find a planet-like object, and what a planet has to consist of to count as a planet. But this question is directed as what orbit or path an object would ...
- 121
1
vote
2
answers
1k
views
What is the unit of time "JD" in an astronomical context?
For my high school physics project I am required to research a planetary system. The orbital period of the planets are given in JD. What are these units? I've tried to research it, and I've found it ...
- 135
1
vote
1
answer
43
views
Can a planemo turn into a star?
I read this question
Why is planet CFBDSIR2149-0403 hot?
and wonder what will happen to this "planemo". Will it attract more mass as it flows around in the gas clouds in space and eventually light ...
- 439
1
vote
1
answer
4k
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Is there a simple formula for calculating semimajor axis bounds of "habitable zone"?
I understand that an accurate determination of the bounds of the "habitable zone" for a given stellar system depends on a large number of factors, including many beyond characteristics of the parent ...
- 5,169
1
vote
1
answer
277
views
Looking for a formula or model for planetary equilibrium temperature which takes into account the greenhouse effect
For a project I'm working on, I have made a bunch of hypothetical random planets orbiting random stars. I have come across the Stefan–Boltzmann law, which works nicely for any planet without an ...
- 11
1
vote
1
answer
85
views
Spectroscopy and the current state of our ability to determine the composition of extra-solar planets
I was interested in learning more about the status of our scientific understanding and technological instruments regarding extra solar spectroscopy.
I am motivated by this almost 3 year old question/...
1
vote
0
answers
44
views
When do planets formed via core accretion in a proto-planetary disk stop gaining mass?
I was just trying to go over some of the contents in my exo planets course and wanted to know that if all the planets that form via core accretion continue to attract all the dust in a proto-planetary ...
- 1,545
0
votes
2
answers
92
views
Study of exoplanets reaching saturation point [closed]
In recent exoplanet meeting The Next 40 Years of Exoplanets, it was mentioned a few times that the field/topic is becoming saturated.
In what ways is it becoming saturated, and can you see the effect ...
- 235
0
votes
3
answers
2k
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Why do gas giants have similarly coloured stripes?
After looking at Jupiter and searching 'exoplanets gas giants' on google I found that many had stripes on them. I found that pretty peculiar. So why do they have stripes. I think it has something to ...
- 2,700
0
votes
2
answers
67
views
How to track orbit of an exoplanet?
I was wondering if there is an established method to keep track of the orbit of an exoplanet assuming we know $a$ - the semi-major axis of the orbit, $e$ - the eccentricity of the orbit, and $i$ - the ...
- 500
0
votes
1
answer
815
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Where to start, if I would like to run a planet climate simulation? [closed]
I would like to understand the math behind it, and maybe write an own climate simulator program. I know, that it is a really hard subject. But I'm curious, and I would like to learn more about it. But ...
- 307
0
votes
1
answer
256
views
What is the difference between habitable and Goldilocks zone?
If I am right, Habitable Zone means that a planet is on such a distance from its Star which makes it good candidate for supporting some sort of life.
But then what is Goldilocks zone and how is it ...
- 117
0
votes
0
answers
41
views
Winds or waves in specific conditions?
Winds are mainly produced by differences in temperature of the atmosphere and waves are mainly produced by winds.
However, could a rogue planet (without orbiting any star and with a cold core so no ...
- 2,878
0
votes
1
answer
123
views
Fusion inside a planet with high concentration of radioactive elements?
If an Earth-sized or larger planet had sufficiently large amounts of radium, thorium or uranium, couldn't the resulting fission trigger periodic fusion of hydrogen? I'm thinking of fission happening ...
- 140
0
votes
1
answer
44
views
how find resonance in extrasolar planet? [closed]
I make this program, i have a 2xN matrix in which the columns are the ID of planets and their period, the rows are the number of planets, for istance something like that:
...
-1
votes
2
answers
98
views
Did we adapt to Earth or Earth to us? [closed]
I often hear that Earth is a unique planet because it has life and it has its own inhabitance. We also see a proper balance between plants and humans and other animals. Why life is not possible on ...
- 12.1k
-2
votes
3
answers
1k
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Why is Mars so cold when it has so much atmospheric $CO_2$?
Mars has 1/10 of Earth's atmosphere but that atmosphere is 95% CO2. Why is Mars so cold when it has so much atmospheric CO2?
- 15