astronomy

List of potentially habitable exoplanets

List of potentially habitable exoplanets is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand List of potentially habitable exoplanets rather than just read about it. In short: The following list includes potentially habitable exoplanets. It is mostly based on estimates of habitability by the Habitable Worlds Catalog (HWC), and data from the NASA Exoplanet Archive.

Key takeaways

List of potentially habitable exoplanets belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect List of potentially habitable exoplanets to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of List of potentially habitable exoplanets from memory before moving on to harder problems.

Reference excerpt

The following list includes potentially habitable exoplanets. It is mostly based on estimates of habitability by the Habitable Worlds Catalog (HWC), and data from the NASA Exoplanet Archive. The HWC is maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. Surface planetary habitability is thought to require an orbit at the right distance from the host star for liquid surface water to be present, in addition to various geophysical and geodynamical aspects, atmospheric density, radiation type and intensity, and the host star's plasma environment.

Main list

This is a list of confirmed exoplanets within the circumstellar habitable zone that are either under 10 Earth masses or smaller than 2.5 Earth radii and thus have a chance of being rocky. Note that inclusion on this list does not guarantee habitability, and in particular the larger planets are less likely to have a rocky composition and more likely to be mini-Neptunes. Earth is included for both comparison and reference, while Venus and Mars are included for reference only. Note that mass and radius values prefixed with "~" have not been measured, but are predicted from a mass–radius relationship.

Current candidates

This is a list of notable exoplanets within the circumstellar habitable zone that are either under 10 Earth masses or smaller than 2.5 Earth radii and have not yet been confirmed. Earth is included for both comparison and reference, while Venus and Mars are included for reference only.

Previous candidates Some habitable exoplanets detected by radial velocity were considered as stellar artifacts by some studies. These include Gliese 581 d and g, Gliese 667 Ce and f, Gliese 682 b and c, Kapteyn b, Gliese 229 Ac, HD 85512 b and Gliese 832 c. Several other planets, such as Gliese 180 b, also appear to be examples of planets once considered potentially habitable but later found to be interior to the habitable zone. Similarly, Tau Ceti e, HD 85512 b and Kepler-69c were thought to be likely habitable, but with improved models of the circumstellar habitable zone, PHL does not consider it potentially habitable. Kepler-438b was also initially considered potentially habitable; however, it was later found to be a subject of powerful flares that can strip a planet of its atmosphere, so it is now considered non-habitable. K2-3d and K2-18b were originally considered potentially habitable, and the latter remains listed in the HWC, but recent studies have shown them to be gaseous sub-Neptunes rather than being the Hycean planet and thus unlikely to be habitable. Kepler-1638b was thought to be a possibly habitable planet with a radius smaller than 2 R🜨 after the validation. However based on the later measurement of host star parallax by Gaia, the radius of the planet was revised upward to 3.226+0.201−0.315 R🜨, meaning it is more likely an ice giant like Neptune with poor prospect for habitability. KOI-1686.01 was also considered a potentially habitable exoplanet after its detection in 2011, until proven a false positive by NASA in 2015. Several other KOIs, like Kepler-577b and Kepler-1649b, were considered potentially habitable prior to confirmation, but with new data are no longer considered habitable. TRAPPIST-1 d was considered to be potentially habitable until JWST/NIRSpec data found little evidence for an atmosphere with Earth-like surface pressure, highly likely ruling out habitability.

Illustrations

Worked examples

Example 1 — a first encounter with List of potentially habitable exoplanets

Start with the simplest possible case. Write down what List of potentially habitable exoplanets claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to List of potentially habitable exoplanets before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about List of potentially habitable exoplanets ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of List of potentially habitable exoplanets

In research: List of potentially habitable exoplanets appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses List of potentially habitable exoplanets in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: List of potentially habitable exoplanets is common in secondary-school and first-year university syllabi. It links to neighbouring topics Exoplanets in the habitable zone, Lists of exoplanets, so understanding it makes those chapters shorter.
In everyday life: Look for List of potentially habitable exoplanets outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study List of potentially habitable exoplanets in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what List of potentially habitable exoplanets means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain List of potentially habitable exoplanets out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is List of potentially habitable exoplanets in simple terms?

The following list includes potentially habitable exoplanets. It is mostly based on estimates of habitability by the Habitable Worlds Catalog (HWC), and data from the NASA Exoplanet Archive.

Why does List of potentially habitable exoplanets matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study List of potentially habitable exoplanets?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on List of potentially habitable exoplanets.