https://www.youtube.com/watch?v=LIHVfExRWgY # **Detailed Outline** The video explains that these 20 exoplanets are being named because they are the first carefully chosen targets for the James Webb Space Telescope, selected to fill specific gaps in understanding how planets change with mass, composition, and distance from their stars. ## Intro and naming context - Explains the IAU’s NameExoWorlds 3 contest, where 20 exoplanets get public-chosen names to replace catalog numbers. - Mentions the creator’s earlier entry focusing on the most potentially habitable of the 20 (Gliese 486 b) and notes that contest results will soon make the video itself outdated. ## Why these 20 planets - States that these worlds are not random: they are the first 20 exoplanets James Webb will study, handpicked (largely by NASA teams) for how observable and informative they are. - Sets the goal: use their known masses, sizes, and orbits to see what each can teach about planetary geology, atmospheres, and the transitions between rocky, icy, and gas planets. ## Terrestrial planets (small rocky) - Orders planets by mass, starting with Gliese 367 b (about half Earth’s mass), used to probe how sub‑Earth-size rocky worlds stay geologically active, sustain plate tectonics, and hold atmospheres. - Discusses Gliese 486 b as a hot “super‑Earth” and compares it to similar‑mass LHS 3844 b, showing how orbital distance and stellar radiation can strip or preserve atmospheres even at the same size. - Covers L 168‑9 b (~5 Earth masses) as the largest rocky candidate, expected to have a very thick, detectable atmosphere but likely a Venus‑like hothouse, rounding out a sequence of rocky planets of increasing mass. ## Transition to ice giants - Uses Uranus and Neptune as reference points to show that around 8–20 Earth masses planets become deeply enveloped in thick atmospheres and ices, hiding any solid surface. - Highlights Gliese 1214 b (~8 Earth masses) as key to the unknown transition zone: it might be a super‑Earth with a huge atmosphere, a mini‑Neptune, or an ocean world, illustrating how uncertain this size range remains. - Introduces Gliese 3470 b (about Uranus‑mass) to test whether an exoplanet twin of Uranus really does resemble it, checking assumptions about “Uranus‑like” planets. ## Growing ice giants and early gas giants - Groups three planets just above Neptune’s mass (HAT‑P‑26 b, Gliese 436 b, LTT 9779 b) to study how ice giants evolve as they gain mass and thicker gaseous envelopes. - Explains that by stepping through this mass range, Webb can track how storms, clouds, and atmospheric structure change as planets approach full gas‑giant status. ## Gas giants from Saturn up to super‑Jupiters - Uses Saturn (95 Earth masses) and Jupiter (over 300 Earth masses) as anchors, noting that most of the list sits between and above these, where theory is weaker. - Describes targets like WASP‑166 b, HATS‑72 b, HAT‑P‑12 b, and WASP‑69 b in the Saturn‑to‑sub‑Jupiter range, chosen to map how atmospheres thicken, storms band, and weather patterns become more “Jupiter‑like.” - Notes WASP‑63 b (~120 Earth masses) as a test of whether anything significant changes between Saturn‑class and Jupiter‑class masses or whether they are broadly similar. ## Extreme hot Jupiters and super‑Jovians - Examines very massive, close‑in gas giants like WASP‑19 b and WASP‑121 b (slightly above Jupiter’s mass) to see how extreme irradiation and gravity affect atmospheric chemistry, winds, and heat distribution. - Moves to even heavier planets: WASP‑43 b (~2 Jupiter masses), HD 95086 b (~5 Jupiters), WD 0806‑661 b (~7.5 Jupiters), and HIP 65426 b (>10 Jupiters), treating them as the upper edge of “planet” before brown dwarfs and stars. - Emphasizes that as mass grows, atmospheres and storms become more energetic and complex, and past a point these objects begin to resemble small stars rather than planets. ## Observational strategy and selection logic - Explains that most targets have extremely tight orbits around their stars, not because they are best for life, but because close‑in planets reflect more starlight and transit more often, making them far easier for Webb to detect and characterize. - Argues that the set was chosen to span key “gaps” in the mass–radius spectrum, letting astronomers calibrate how composition and structure change smoothly from small rocky worlds to giant planets and near‑stellar objects. ## Role of HIP 65426 b and knowledge limit - Points out that HIP 65426 b, already imaged directly by Webb in 2022, is both extremely massive and bright, making it a practical first test case for exoplanet imaging with the telescope. - Frames HIP 65426 b as close to the current frontier of planetary science: large enough to be easily studied yet still classified as a planet rather than a star, marking where the “planet” regime ends and stellar physics begins. ## Closing ideas and sponsor segment - Concludes that the 20 exoplanets receiving new names are effectively the “training set” Webb uses to build a general theory of planetary mechanics applicable across many systems, not a list of likely abodes for life. - Ends with a sponsor segment for Brilliant.org, connecting the video’s themes to interactive learning in astrophysics and related STEM topics. 1. [https://www.youtube.com/watch?v=LIHVfExRWgY](https://www.youtube.com/watch?v=LIHVfExRWgY) --- ### [@Planetkid32](https://www.youtube.com/@Planetkid32) Since this video was originally posted before the final results were revealed, here are the names that were ultimately selected for the planets in NameExoWorlds 2022: Gliese 1214 b - Enaiposhia Gliese 3470 b - Phailinsiam Gliese 367 b - Tahay Gliese 436 b - Awohali Gliese 486 b - Su (not Eurypterus) HAT-P-12 b - Puli HAT-P-26 b - Guataubá HATS-72 b - Zembretta HD 95086 b - Levantes HIP 65426 b - Najsakopajk L 168-9 b - Qingluan LHS 3844 b - Kua’kua LTT 9779 b - Cuancoá WASP-121 b - Tylos WASP-166 b - Catalineta WASP-19 b Banksia WASP-43 b - Astrolábos WASP-63 b - Regoč WASP-69 b - Makombé WD 0806-661 b - Ahra ----