Questions tagged [exoplanets]

Exoplanets (also known as Exosolar or Extrasolar planets) are planets outside the solar system.

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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 ...
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Lift and drag coefficients on other planets

The question I'm trying to answer seemed simple: how hard would it be to fly on a planet with lower gravity but also thinner atmosphere compared to Earth. If the answer could hint me at how much ...
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How close would Earth have to be for us to detect it was habitable, and then inhabited?

Given our current technology (or technology that is near implementation), how close would a clone of our Solar System (and so also Earth) have to be to us in order to detect that the cloned Earth was ...
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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 ...
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How can spectroscopy be used to find the composition of exoplanet atmospheres?

How can astronomers use light spectroscopy to measure the composition of different planets when they can't directly image the planet because the star that they are orbiting is so much bigger and ...
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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 ...
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Is our solar system really that odd?

I have been learning about the solar system from popular science shows. In these shows they suggest that, after having seeing around 2500 other solar systems, astronomers have concluded that our ...
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Atmospheres and oceans on lower gravity planets

Using Earth as an example, how much less gravity could the planet exert and still retain its atmosphere and oceans? Or is it a matter of size, mass, magnetosphere, place in the solar system, all of ...
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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 ...
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Infrared Telescopes and Surface Area

I have been reading a paper on about exoplanets, specifically measuring the temperature of exoplanets using infrared telescopes. The paper compares exoplanets with neutron stars (NS) remarking that ...
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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 ...
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Research on exoplanets using available data from TESS

I am a high school student who is proposing research on exoplanets for my junior research project, I have several questions: I have seen studies where researchers survey star systems and then find ...
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Proxima Centauri radio signal

I have recently seen an article about an unusual radio signal coming from Proxima Centauri region. I understand there is a debate around the nature of this signal. My question is related to this ...
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How do Astronomers Measure the Mass of a Planet using Doppler Spectroscopy?

So, I am making an essay explaining planet-hunting techniques. And while I do get how astronomers measure the semi-major axis of a planetary orbit (using Kepler Laws), I don't get how they measure the ...
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Exoplanet surface detail: Limitations on size of space telescope array

How big could an array of space telescopes acting as an interferometer be ? How big would it have to be to resolve exoplanet surface detail the size of Iceland at a distance of 100 light years ?
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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 ...
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Simulation of relativistic probe passing through an external solar system

I recently read about the Breakthrough Initiative to launch "StarShot", a nano-probe that is designed to travel to Alpha Centauri at $0.2c$. One of the challenges to be solved involves the precise ...
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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 ...
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Datasets for calculation of exoplanet properties

I would like to create program for calculation exoplanet properties, but I only found transit dataset from Kepler on NASA website. From light curve I can calculate: planet radius $r$ from $\frac{r_{...
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Global Circulation Model of tidally locked planets for PC?

Is there some free simple Global Circulation Model that can handle tidally locked planets and can be easily compiled and used on a PC computer? It does not have to be very precise, I am interested ...
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Which planets of our solar system could be discovered from another solar system with present technology?

Recently many exoplanets have been found orbiting nearby stars. Assume there is a civilization with identical technology residing in a nearby (< 100 light years) solar system. Could they discover ...
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Can we know if an exoplanet has a magnetic field?

The recent discovery of the exoplanet Proxima b gave rise to several questions concerning its habitability and its potential to host life. A major concern is the huge amount of radiation coming from ...
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Formation of Life on various planets

Is there any theory that suggests every creature (including bacteria and fungi) in our planet is formed by the atoms of our planet. If that is true, then is it possible that any other organisms will ...
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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 ...
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Why is relativistic beaming/ Doppler beaming occur at non-relativistic speeds

The reflexive motion of a binary star system causes the host star to occasionally wobble towards and away from an observer on Earth, which gives rise to an effect called relativistic beaming. This is ...
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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 ...
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On Planets orbiting binary stars

Several years ago a discovery was made of planet orbiting a star of a binary system (two stars orbiting each other). Since binary star systems are plentiful in our galaxy, I presume we will be ...
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How is global warming distributed with respect to altitude?

Lets assume a sea level temperature increase 2c/3c. Then, what is the temperature increase at 10 km altitude? Temperature increase at 30 km altitude? Temperature increase at 70 km altitude? And ...
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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 ...
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Finding distance Range for an Exoplanet to be detectable

I have been trying to solve the following problem, I found while reading some Exoplanet detection techniques, namely, radial velocity method and Astrometry. Problem statement: " Imagine yourself ...
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Rayleigh Scattering and Red Giants

Rayleigh scattering is responsible for the color of the sky. Consider a planet with an atmospheric composition similar to Earth's but orbiting a red giant. Suppose further that the planet is in the ...
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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?
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Non-discoveries by the Kepler space telescope: exomoons, co-orbital planets, trojans

I am just reading the review article Advances in exoplanet science from Kepler (arxiv preprint: http://arxiv.org/abs/1409.1595), and I found a remarkable paragraph (last paragraph in section "...
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How does TESS focus on bright nearby stars?

How does the Transiting Exoplanet Survey Satellite "focus on" bright nearby stars, in contrast to the Kepler Mission's focus on dim distant stars? I understand that the fields of view of the two ...
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Doppler method for detecting exoplanets

Why does the Doppler method for detecting exoplanets only give the minimum mass for the exoplanet and not the actual mass? Is it to do with whether the exoplanet is a face on orbit or a side on ...
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Why does a starshade have to be put so far away from the telescope?

I understand why starshades have the shape they do, but i don't seem to understand why they have to be put so far away from the telescope. Why can't we keep the same apodization function, but just ...
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Sodium sometimes absorbs orange-yellow light, sometimes emits it? Huh?

Usually, we are told that sodium emits orangish-yellowish light, which is why city streetlamps are that color. Now, I read in New Scientist magazine that exoplanet WASP-96b is bluish because the ...
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Do any naked-eye stars have planets

Are there any known exoplanets around naked-eye stars? I know that Fomalhaut has a planet, and Vega has a dust belt that may be a protoplanetary disk or even analogous to our Kuiper belt. What else is ...
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Have scientists thought about these two questions? [closed]

I would like to know if our vision bends with the earth or if the earth truly is round. If I look through a strong enough telescope to see around the world, would I be able to see the back of my head? ...
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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 ...
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Gas giant evolution over lifetime

In various types of stars, one can learn how they evolve differently, depending on factors such as their size and chemistry. Some stars have a short lifetime and others much longer. But, what is ...
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are alignment of star systems' orbital planes with ours better than random?

It obviously helps our observation of exoplanets if they transit their star from our point-of-view. I would guess that the chances of this alignment are better than if their orbital plane was randomly ...
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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 ...
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Why do we refer to life on Earth when we talk about life on other planets? [closed]

I have always had thoughts about extraterrestrial life and I wonder why researchers largely compare the conditions for existence of life to that on the Earth? Is it impossible that on a remote ...
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In searching for an exoplanet by observing transitions, isn't it rather rare that an orbital plane would line up with Earth?

Given that we are at a random orientation to any remote star system, it seems to me that there is only a narrow angle at which transits of exoplanets can be observed. Imagine a large mathematical ...
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Planets capable of life: dead or still alive?

There are some planets that scientists speculate may be capable of supporting life. However, these planets are hundreds of light years away. How can we be sure they are still capable of supporting ...
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Exoplanet detection via space-based parasol

I remember from watching Cosmos years ago, Carl Sagan suggested an interesting hypothetical method for directly seeing exoplanets. He proposed that in the 'future' we could launch a satellite designed ...
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Do stars of higher metallicity have more planets in highly-inclined Pluto-like orbits?

In an answer to a previous question of mine, one that asked about the planar orbits of inner planets, I was told the following (emphasis mine): On the subject of different solar systems, I would ...
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Why did population III stars lack planets?

Jay Wacker1 (professor of physics at the SLAC National Accelerator Laboratory) stated: The first stars (known as Pop III) were made out of hydrogen and helium. They had no planets. Why couldn't ...
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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 ...