673:
58:
685:
20:
46:
637:
661:
649:
31:
140:
603:"'Mini-Neptunes' beyond solar system may soon yield signs of life – Cambridge astronomers identify new hycean class of habitable exoplanets, which could accelerate search for life"
602:
705:
106:
128:
150:
627:
341:
A hot, water-covered planet with a hydrogen-rich atmosphere that is possibly capable of harboring extremophilic life.
144:
518:
370:
362:
24:
356:
672:
30:
574:
537:
470:
269:
122:
74:
101:, and speculation has included different kinds of stars, planets, and other astronomical objects.
677:
665:
555:
527:
203:
97:
Hypothetical astronomical objects have been speculated to exist both inside and outside of the
57:
494:
486:
233:
112:
641:
545:
478:
316:
211:
78:
66:
38:
413:
380:
245:
134:
541:
474:
689:
579:
407:
400:
288:
planet where uneven heating of the surface induces spatial features resembling a human
279:
251:
699:
559:
394:
311:
297:
285:
259:
237:
197:
50:
19:
684:
653:
607:
346:
98:
86:
512:
Madhusudhan, Nikku; Piette, Anjali a. A.; Constantinou, Savvas (26 August 2021).
217:
118:
62:
34:
550:
513:
89:", around which he proposed other celestial bodies (including the Sun) moved.
490:
375:
A planet that was originally a moon but has become gravitationally detached.
139:
For stars, planets or moons whose existence is not accepted by science, see:
458:
303:
141:
Planetary objects proposed in religion, astrology, ufology and pseudoscience
82:
498:
45:
482:
424:
A planet with significant amount of strong acids, including sulfuric acid
229:
220:
whose outer layers have been completely stripped off by its parent star.
179:
459:"The potential feasibility of chlorinic photosynthesis on exoplanets"
187:
133:
For extrasolar moons, all of which are currently hypothetical, see:
648:
532:
386:
56:
44:
29:
18:
105:
For hypothetical astronomical objects in the Solar System, see:
85:
defined a hypothetical astronomical object which he called the "
331:
289:
53:. The surface is dark and reddish from hydrocarbon deposits.
351:
A planet whose surface is covered entirely by deep oceans.
325:
328:
81:. For example, in the 5th century BCE, the philosopher
445:
Distinguished
Figures in Mechanism and Machine Science
625:
322:
319:
274:A planet that locates outside the Milky Way galaxy
206:composed primarily of carbon, rather than silicon.
16:
Astronomical bodies believed or speculated to exist
161:Hypothetical types of extrasolar planets include:
514:"Habitability and Biosignatures of Hycean Worlds"
575:"Hycean planets might be habitable ocean worlds"
306:composed mainly of helium instead of hydrogen.
264:A terrestrial planet with little to no water.
8:
192:A planet that directly orbits a black hole.
250:A terrestrial planet that has no metallic
228:A planet with significant amounts of free
149:For hypothetical planets in fiction, see:
93:Types of hypothetical astronomical objects
549:
531:
107:List of hypothetical Solar System objects
163:
41:initially mistaken for a moon of Mercury
23:Artist's concept of Earth, orbited by a
632:
573:Anderson, Paul Scott (29 August 2021).
436:
182:. May have lakes or oceans of ammonia.
178:A planet with significant amounts of
151:Fictional planets of the Solar System
7:
127:For hypothetical black holes, see:
457:Haas, Johnson R. (November 2010).
361:A terrestrial planet that is more
77:have been hypothesized throughout
14:
706:Hypothetical astronomical objects
385:A planet whose shape resembles a
683:
671:
659:
647:
635:
601:Davis, Nicola (25 August 2021).
315:
399:A planet that orbits near the
1:
111:For hypothetical stars, see:
722:
416:of a more massive object.
145:Stars proposed in religion
519:The Astrophysical Journal
157:Hypothetical planet types
551:10.3847/1538-4357/abfd9c
371:Tidally detached exomoon
25:hypothetical second moon
129:Hypothetical black hole
61:Artist's conception of
70:
54:
49:Artist's concept of a
42:
27:
483:10.1089/ast.2009.0364
357:Superhabitable planet
69:, transiting its star
60:
48:
33:
22:
270:Extragalactic planet
123:List of brown dwarfs
75:astronomical objects
542:2021ApJ...918....1M
475:2010AsBio..10..953H
443:Marco Ceccarelli,
204:terrestrial planet
71:
55:
43:
28:
428:
427:
421:Vitriolic planet
234:hydrochloric acid
117:For hypothetical
113:Hypothetical star
713:
688:
687:
676:
675:
664:
663:
662:
652:
651:
640:
639:
638:
631:
620:
619:
617:
615:
598:
592:
591:
589:
587:
570:
564:
563:
553:
535:
509:
503:
502:
454:
448:
441:
338:
337:
334:
333:
330:
327:
324:
321:
212:Chthonian planet
164:
79:recorded history
73:Various unknown
67:Chthonian planet
39:eclipsing binary
721:
720:
716:
715:
714:
712:
711:
710:
696:
695:
694:
682:
670:
660:
658:
646:
636:
634:
626:
624:
623:
613:
611:
600:
599:
595:
585:
583:
580:Earth & Sky
572:
571:
567:
511:
510:
506:
456:
455:
451:
447:(2007), p. 124.
442:
438:
433:
414:Lagrange points
411:
404:
381:Toroidal planet
318:
314:
246:Coreless planet
225:Chlorine planet
175:Ammonia planet
159:
135:Extrasolar moon
95:
17:
12:
11:
5:
719:
717:
709:
708:
698:
697:
693:
692:
680:
668:
656:
644:
622:
621:
593:
565:
504:
469:(9): 953–963.
449:
435:
434:
432:
429:
426:
425:
422:
418:
417:
409:
402:
397:
391:
390:
383:
377:
376:
373:
367:
366:
359:
353:
352:
349:
343:
342:
339:
308:
307:
300:
294:
293:
286:tidally locked
282:
280:Eyeball planet
276:
275:
272:
266:
265:
262:
256:
255:
248:
242:
241:
226:
222:
221:
214:
208:
207:
200:
194:
193:
190:
184:
183:
176:
172:
171:
168:
158:
155:
154:
153:
147:
137:
131:
125:
115:
109:
94:
91:
15:
13:
10:
9:
6:
4:
3:
2:
718:
707:
704:
703:
701:
691:
686:
681:
679:
674:
669:
667:
657:
655:
650:
645:
643:
633:
629:
610:
609:
604:
597:
594:
582:
581:
576:
569:
566:
561:
557:
552:
547:
543:
539:
534:
529:
525:
521:
520:
515:
508:
505:
500:
496:
492:
488:
484:
480:
476:
472:
468:
464:
460:
453:
450:
446:
440:
437:
430:
423:
420:
419:
415:
412:
405:
398:
396:
395:Trojan planet
393:
392:
389:or doughnut.
388:
384:
382:
379:
378:
374:
372:
369:
368:
364:
360:
358:
355:
354:
350:
348:
345:
344:
340:
336:
313:
312:Hycean planet
310:
309:
305:
301:
299:
298:Helium planet
296:
295:
291:
287:
283:
281:
278:
277:
273:
271:
268:
267:
263:
261:
260:Desert planet
258:
257:
253:
249:
247:
244:
243:
239:
238:muriatic acid
235:
231:
227:
224:
223:
219:
215:
213:
210:
209:
205:
201:
199:
198:Carbon planet
196:
195:
191:
189:
186:
185:
181:
177:
174:
173:
169:
166:
165:
162:
156:
152:
148:
146:
142:
138:
136:
132:
130:
126:
124:
120:
116:
114:
110:
108:
104:
103:
102:
100:
92:
90:
88:
84:
80:
76:
68:
65:, a possible
64:
59:
52:
51:carbon planet
47:
40:
37:, a possible
36:
32:
26:
21:
612:. Retrieved
608:The Guardian
606:
596:
584:. Retrieved
578:
568:
523:
517:
507:
466:
463:Astrobiology
462:
452:
444:
439:
365:than Earth.
347:Ocean planet
170:Description
160:
119:brown dwarfs
99:Solar System
96:
87:Central Fire
72:
678:Mathematics
666:Outer space
614:12 December
586:12 December
218:hot Jupiter
63:HD 209458 b
35:31 Crateris
533:2108.10888
431:References
642:Astronomy
560:237290118
491:1557-8070
363:habitable
304:gas giant
83:Philolaus
700:Category
526:(1): 1.
499:21118026
230:chlorine
690:Science
628:Portals
538:Bibcode
471:Bibcode
180:ammonia
121:, see:
558:
497:
489:
188:Blanet
654:Stars
556:S2CID
528:arXiv
387:torus
167:Type
616:2021
588:2021
495:PMID
487:ISSN
252:core
236:and
143:and
546:doi
524:918
479:doi
406:or
290:eye
232:or
702::
605:.
577:.
554:.
544:.
536:.
522:.
516:.
493:.
485:.
477:.
467:10
465:.
461:.
332:ən
326:aɪ
302:A
292:.
284:A
254:.
240:.
216:A
202:A
630::
618:.
590:.
562:.
548::
540::
530::
501:.
481::
473::
410:5
408:L
403:4
401:L
335:/
329:ʃ
323:h
320:ˈ
317:/
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
