30 votes
Accepted

Are images of exoplanets' surfaces technically possible?

With a resolution of 1E-09 radians, Jupiter would be 1 pixel wide at 7 light years. If you had 1E-10 radians, you could resolve the largest features. Visible light has a wavelength of 5E-07 meters, ...
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  • 148k
26 votes
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Why would Kepler rotate towards Earth to transfer data?

Kepler has a parabolic dish antenna fixed to its body. There are many possible designs of transmitting devices. For spacecraft, parabolic dish antennas are preferred, because they have the least ...
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  • 8,446
22 votes
Accepted

What concentration of oxygen in a planetary atmosphere would be indicative of life?

I would argue that no specific level of molecular or atomic oxygen in atmosphere is indicative of carbon-based life (i.e. life as we know it on Earth). A planet could have oxygen rich atmosphere which ...
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  • 75.5k
20 votes

When will we have the technology to directly observe an exoplanet with significant clarity?

It's not currently possible to get the details of a planet from a distance like a light year or more. Furthermore the projects mentioned below do not aim to get good images of the surface, but only to ...
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  • 4,853
15 votes

Technology for unmanned spacecraft to exoplanets

There are incredible, mindboggling distances involved in merely reaching an exoplanet. Alpha Centauri Bb, the closest known exoplanet, is 4.365 light years away. That's 41,295,000,000,000 km (25,660,...
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14 votes
Accepted

Why is TRAPPIST-1f considered habitable?

None of the TRAPPIST-1 planets are "considered habitable"; we don't know nearly enough about them to say that (any news article which referred to the planets themselves as "habitable" needs firm ...
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13 votes
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Which of the planets could we detect today from just the movements of the sun?

Getting hard numbers about how accurate measures we can get from current systems, adapted to the Sun instead of far away stars is difficult, bordering to impossible. But we can get data about the ...
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13 votes

Dark side of an exoplanet - if it was earth-like would its surface light be detectable?

Keep in mind that earth like exoplanets are mostly found as they cross in front of their sun. If you hold a flashlight between you and the sun, you would not be able to tell if it was on or off, ...
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13 votes

Agriculture on an exoplanet

Ignoring the infrared radiation aspect of your question, what you are describing is a situation not too dissimilar to what exists in many parts of Australia. The extreme degree of weathering that has ...
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  • 10.7k
12 votes
Accepted

When will we be able to conclusively confirm or disprove Bode's law?

I would argue that it is disproven already. There have been studies done with Extrasolar planets, and it has been found to only apply in a very small number of instances. There might be some that ...
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  • 118k
11 votes

A Jupiter-sized star?

Jupiter is about as large as a planet can get, physically. Suppose we slowly add hydrogen and helium to Jupiter, so slowly so as to keep it at more or less its current temperature. Surprisingly, it ...
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  • 64.2k
10 votes

Technology for unmanned spacecraft to exoplanets

But I would think an unmanned spacecraft sent for a flyby of an expolanet would be a revolutionary step in this field. Better said: Impossible, at least using anything close to current technology. ...
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  • 64.2k
10 votes

What concentration of oxygen in a planetary atmosphere would be indicative of life?

As @TidalWave said, no specific level of oxygen is by itself sufficient to potentially indicate life. However, based on this article, what astronomers are looking for is the combination of both ...
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  • 574
9 votes

What concentration of oxygen in a planetary atmosphere would be indicative of life?

The first third of Earth's own existence had neglible atmospheric oxygen. (Simple) life existed during a few hundred million years of this period. Thus, atmospheric oxygen does not correlate with ...
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9 votes
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How do we determine and estimate the age of exoplanets like Kepler-452b?

From here: The age of the exoplanet is not independently derived, but instead, taken from the age of the host star. So how do they calculate the age of the host star? Wikipedia has a number of ...
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  • 7,106
9 votes

Would an interstellar exoplanet telescope make sense?

@SF. is right. It is true that a location far from Earth could have access to different orbital planes and thus potentially see a different set of occultations an transits, you would have to move very ...
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  • 148k
9 votes

How to calculate density of unknown planet?

Planets are usually rotating, and so you can't time two passes over a single geographical feature to time an orbit. But you can time successive sunrises to get a good approximation of the orbital ...
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  • 148k
9 votes

Dark side of an exoplanet - if it was earth-like would its surface light be detectable?

City lights are not detectable today, but it is possible in the future. It would require: future generations of telescopes on the ground and in space that would have the capacity to detect phase ...
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  • 23.5k
8 votes

The gases of technology

The best method of analyzing exoplanet atmospheres is called Transit Absorption Spectroscopy. First, we analyze the spectrum of an exoplanet's star. Then, we wait for the planet to pass in front of ...
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  • 5,571
8 votes

Why is TRAPPIST-1f considered habitable?

The temperature estimate is based on no atmosphere. For instance, Earth, without our atmosphere, would have an average temperature of -20°C . The equator should be warmer, and any atmosphere will also ...
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  • 118k
8 votes
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How could I find a potentially habitable exoplanet in same direction as Kepler-186f?

Here is a map of all known exoplanets Go to the link and click in the tight bunch of dots in the upper left - that is the section of sky Kepler is searching. Kepler 186 is at 19h54m37s by 43d57m. ...
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  • 20.8k
8 votes
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Can we make super-massive Telescopes to image exoplanets?

So the main thing of interest in this post seems to be angular resolution. You're after objects that are relatively bright and small. Angular resolution increases linearly with aperture size. However, ...
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  • 6,125
8 votes
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Why are all possibly habitable exoplanets higher mass than Earth?

There is a nice Wikipedia article about the transit method for finding exoplanets by detection of the light intensity drop caused by the planet when passing before its central star. Unfortunately this ...
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  • 46.6k
8 votes

Agriculture on an exoplanet

In general space based plants will probably be hydroponics so most likely initial agriculture will be indoors in vertical farms. Possibly using mechanically harvested/processed materials to carefully ...
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7 votes

Technology for unmanned spacecraft to exoplanets

The most feasible that I've seen, which isn't all that high on the feasibility scale, is a very large, very low mass wire mesh containing sensors that is accelerated and powered by a microwave beam ...
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  • 57.6k
7 votes

Could a 21 meter space telescope detect the nearest exoplanets?

As of 2017, 22 exoplanets have been imaged directly. The most distant of those is 1200 ly away. This shows 4 of them orbiting HR 8799, which is 128 ly away: These observations are good enough to ...
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  • 121k
7 votes

Why would Kepler rotate towards Earth to transfer data?

Why would Kepler rotate towards Earth instead having an antenna always directed to Earth? There was no need to always have an antenna pointed directly at the Earth because communication with the ...
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  • 64.2k
7 votes

Dark side of an exoplanet - if it was earth-like would its surface light be detectable?

Exoplanets are found in a variety of ways. Two rather common ways are star transits and radial velocity changes. Star transits are found by continuously measuring the brightness of the Star, and ...
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6 votes

What concentration of oxygen in a planetary atmosphere would be indicative of life?

Oxygen is a highly reactive element. Gaseous oxygen rapidly combines with other elements. If there's any large amount of free oxygen in the atmosphere, after any significant amount of geological time, ...
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