386:
367:
406:
20:
216:
347:
1793:
658:
145:
232:
The physical nature of lunar rays has historically been a subject of speculation. Early hypotheses suggested that they were deposits of salt from evaporated water. Later they were thought to be deposits of volcanic ash or streaks of dust. After the impact origin of craters became accepted,
244:(FeO). Low portions of FeO result in brighter materials, so such a ray system can retain its lighter appearance for longer periods. Thus the material composition needs to be factored into the albedo analysis to determine age.
183:
The layering of rays across other surface features can be useful as an indicator of the relative age of the impact crater, because over time various processes obliterate the rays. On non-atmosphered bodies such as the Moon,
168:) or thermal properties from the surface on which they are deposited. Typically, visible rays have a higher albedo than the surrounding surface. More rarely an impact will excavate low albedo material, for example
1769:
385:
240:
Recent studies suggest that the relative brightness of a lunar ray system is not always a reliable indicator of the age of a ray system. Instead the albedo also depends on the portion of
1716:
196:
causes a steady reduction of the differential between the ejecta's albedo and that of the underlying material. Micrometeorites in particular produce a glassy melt in the
318:
Most lateral transport of primary ejecta from impact craters is limited to a distance of a few crater radii, but some larger impacts, such as the impacts that made the
1674:
180:. Thermal rays, as seen on Mars, are especially apparent at night when slopes and shadows do not influence the infrared energy emitted by the Martian surface.
96:
of their originating crater, and are often accompanied by small secondary craters formed by larger chunks of ejecta. Ray systems have been identified on the
1709:
346:
366:
1702:
1349:
458:
1283:
1688:
1681:
518:
Chipping pieces off Mars: Martian craters with rays may be the long-sought sources for the Mars meteorites found on Earth
551:
405:
38:
1747:
1732:
429:
1154:
1140:
153:
138:
1306:
1299:
1276:
586:
967:
772:
1335:
1478:
1048:
1041:
1027:
983:
1147:
795:
689:
675:
623:
35:. This 30 m (98 ft) diameter crater formed between July 2010 and May 2012 (19 November 2013;
990:
958:
319:
252:
220:
121:
1372:
1232:
1818:
1695:
1326:
1200:
940:
630:
607:
392:
376:
292:
1239:
870:
644:
600:
544:
484:
1776:
1292:
1262:
974:
905:
256:
522:
517:
476:
1605:
1591:
1409:
1358:
912:
248:
209:
89:
336:
craters, each with a clear ray system, were observed from the ground by the astronauts of
8:
1388:
1225:
569:
276:
237:
suggested during the 1960s that the rays were the result of fragmented ejecta material.
1573:
1425:
1193:
1094:
841:
779:
737:
411:
333:
329:
264:
1755:
1515:
1214:
1179:
1172:
666:
537:
477:
372:
312:
130:
113:
71:
284:
1651:
1315:
1117:
933:
926:
886:
728:
682:
657:
509:
504:
353:
304:
268:
260:
234:
185:
109:
19:
1658:
1395:
1248:
1011:
288:
280:
164:
wavelengths, when ejecta are made of material with different reflectivity (i.e.,
1418:
1342:
1207:
1124:
1101:
323:
296:
272:
215:
1812:
1796:
1762:
1644:
1538:
1471:
1080:
1020:
857:
834:
802:
788:
765:
308:
88:, looking somewhat like many thin spokes coming from the hub of a wheel. The
85:
53:
40:
24:
1630:
1446:
1365:
1186:
1064:
879:
719:
593:
462:
434:
300:
105:
1004:
116:
of the outer planets. Originally it was thought that they existed only on
16:
Radial streaks of material thrown out during formation of an impact crater
1739:
1723:
1665:
1637:
1623:
1598:
1489:
1439:
1110:
848:
827:
614:
247:
Among the lunar craters on the near side with pronounced ray systems are
1552:
1131:
1057:
997:
951:
893:
712:
241:
189:
177:
1559:
1545:
1531:
1508:
1457:
1087:
811:
751:
705:
637:
415:
396:
357:
337:
1566:
1524:
1501:
1379:
744:
197:
161:
93:
758:
201:
193:
169:
165:
117:
80:
32:
1432:
1255:
1073:
696:
101:
1464:
820:
560:
326:
craters, launched primary ejecta halfway around the moon.
205:
173:
149:
144:
125:
97:
28:
523:
http://www.astronomy.com/asy/default.aspx?c=a&id=2980
395:
extend for hundreds of kilometers from the small crater (
291:
of the Moon, such as the rays radiating from the craters
459:
Spectacular new
Martian impact crater spotted from orbit
529:
212:
on the moon), or by other impact craters or ejecta.
505:Lunar Crater Rays Point to a New Lunar Time Scale
483:. Cambridge: Cambridge University Press. p.
124:, but more recently they have been identified on
1810:
510:http://www.psrd.hawaii.edu/Sept04/LunarRays.html
352:Asymmetrical ray system about the lunar crater
92:may extend for lengths up to several times the
545:
156:at night. Image covers an area 32 km across.
479:Lunar SourceBook: A Users Guide to the Moon
552:
538:
508:, Planetary Science Research Discoveries.
160:Rays appear at visible, and in some cases
287:. Similar ray systems also occur on the
223:, one of the freshest craters on Mercury
214:
143:
18:
128:in infrared images taken from orbit by
1811:
474:
84:thrown out during the formation of an
533:
148:Gratteri crater, a rayed crater on
13:
204:. Rays can also become covered by
31:showing a prominent ray system of
14:
1830:
1770:Lilith (hypothetical second moon)
78:comprises radial streaks of fine
1792:
1791:
1733:Moon landing conspiracy theories
656:
430:List of craters with ray systems
404:
384:
365:
345:
1155:Selenographic coordinate system
1034:
1682:Artificial objects on the Moon
468:
452:
311:, and the small but prominent
1:
773:Total penumbral lunar eclipse
521:, Astronomy Magazine Online.
502:Martel, L.M.V. (Sept., 2004)
440:
227:
1748:Moon is made of green cheese
1042:Permanently shadowed craters
445:
7:
423:
275:. Smaller examples include
10:
1835:
1675:Craters named after people
1148:Transient lunar phenomenon
796:Solar eclipses on the Moon
515:Burnham, R. (March, 2005)
495:
1786:
1615:
1583:
1488:
1405:
1325:
1164:
867:
665:
654:
576:
567:
559:
208:flows (such as those of
1696:Moon in science fiction
1201:Giant-impact hypothesis
1049:South Pole–Aitken basin
1717:futuristic exploration
1240:Late Heavy Bombardment
512:. (Accessed 9/15/2005)
475:French, Bevan (1991).
224:
157:
67:
1777:Splitting of the Moon
1689:Memorials on the Moon
1293:Lunar sample displays
975:Peak of eternal light
218:
147:
22:
525:(Accessed 8/07/2006)
120:or moons lacking an
1277:Lunar laser ranging
152:that was imaged by
50: /
1426:Lunisolar calendar
1095:Lunar basalt 70017
842:Tidal acceleration
697:Perigee and apogee
587:Internal structure
375:crater (Mosaic of
225:
158:
68:
1806:
1805:
1756:Natural satellite
1215:Lunar magma ocean
991:Volcanic features
188:from exposure to
131:2001 Mars Odyssey
72:planetary geology
1826:
1799:
1795:
1794:
1779:
1772:
1765:
1758:
1751:
1742:
1735:
1726:
1719:
1712:
1705:
1698:
1691:
1684:
1677:
1668:
1661:
1654:
1647:
1640:
1633:
1626:
1608:
1601:
1599:Meridian passage
1594:
1576:
1569:
1562:
1555:
1548:
1541:
1534:
1527:
1518:
1511:
1504:
1481:
1474:
1467:
1460:
1449:
1442:
1435:
1428:
1421:
1398:
1391:
1382:
1375:
1368:
1361:
1352:
1345:
1338:
1318:
1316:Lunar seismology
1309:
1302:
1295:
1286:
1279:
1272:
1265:
1258:
1251:
1249:Lunar meteorites
1242:
1235:
1228:
1217:
1210:
1203:
1196:
1189:
1182:
1175:
1157:
1150:
1143:
1134:
1127:
1120:
1118:Space weathering
1113:
1104:
1097:
1090:
1083:
1076:
1067:
1060:
1051:
1044:
1037:
1030:
1023:
1014:
1007:
1000:
993:
986:
977:
970:
961:
954:
943:
936:
929:
922:
915:
908:
901:
896:
889:
882:
860:
851:
844:
837:
830:
823:
814:
805:
798:
791:
782:
775:
768:
761:
754:
747:
740:
731:
722:
715:
708:
699:
692:
685:
683:Orbital elements
678:
660:
647:
640:
633:
626:
617:
610:
603:
596:
589:
554:
547:
540:
531:
530:
489:
488:
482:
472:
466:
456:
408:
388:
369:
349:
235:Eugene Shoemaker
200:that lowers the
186:space weathering
176:deposits on the
136:
65:
64:
62:
61:
60:
55:
51:
48:
47:
46:
43:
1834:
1833:
1829:
1828:
1827:
1825:
1824:
1823:
1809:
1808:
1807:
1802:
1790:
1782:
1775:
1768:
1761:
1754:
1745:
1738:
1731:
1722:
1715:
1708:
1701:
1694:
1687:
1680:
1673:
1664:
1659:Man in the Moon
1657:
1650:
1643:
1636:
1629:
1622:
1611:
1604:
1597:
1590:
1584:Daily phenomena
1579:
1572:
1565:
1558:
1551:
1544:
1537:
1532:Super and micro
1530:
1523:
1514:
1507:
1500:
1493:
1484:
1477:
1470:
1463:
1456:
1445:
1438:
1431:
1424:
1417:
1407:
1401:
1396:Lunar resources
1394:
1387:
1378:
1371:
1364:
1357:
1348:
1341:
1334:
1321:
1314:
1305:
1298:
1291:
1282:
1275:
1270:
1261:
1254:
1247:
1238:
1231:
1224:
1213:
1206:
1199:
1192:
1185:
1178:
1171:
1160:
1153:
1146:
1139:
1130:
1123:
1116:
1109:
1100:
1093:
1086:
1079:
1072:
1063:
1056:
1047:
1040:
1033:
1026:
1019:
1010:
1003:
996:
989:
982:
973:
966:
957:
950:
939:
932:
925:
920:
911:
904:
899:
892:
885:
878:
869:
863:
856:
847:
840:
833:
826:
819:
810:
801:
794:
787:
778:
771:
764:
757:
750:
743:
736:
727:
718:
711:
704:
695:
688:
681:
674:
661:
652:
643:
636:
629:
622:
613:
606:
599:
592:
585:
578:
572:
563:
558:
528:
498:
493:
492:
473:
469:
457:
453:
448:
443:
426:
419:
409:
400:
389:
380:
370:
361:
350:
230:
194:micrometeorites
134:
58:
56:
52:
49:
44:
41:
39:
37:
36:
17:
12:
11:
5:
1832:
1822:
1821:
1819:Impact craters
1804:
1803:
1801:
1800:
1787:
1784:
1783:
1781:
1780:
1773:
1766:
1759:
1752:
1743:
1736:
1729:
1728:
1727:
1720:
1713:
1706:
1692:
1685:
1678:
1671:
1670:
1669:
1662:
1648:
1641:
1634:
1627:
1619:
1617:
1613:
1612:
1610:
1609:
1602:
1595:
1587:
1585:
1581:
1580:
1578:
1577:
1570:
1563:
1556:
1549:
1542:
1535:
1528:
1521:
1520:
1519:
1505:
1497:
1495:
1486:
1485:
1483:
1482:
1479:Lunar distance
1475:
1468:
1461:
1454:
1453:
1452:
1451:
1450:
1429:
1422:
1419:Lunar calendar
1414:
1412:
1403:
1402:
1400:
1399:
1392:
1385:
1384:
1383:
1369:
1362:
1355:
1354:
1353:
1346:
1343:Apollo program
1331:
1329:
1323:
1322:
1320:
1319:
1312:
1311:
1310:
1303:
1289:
1288:
1287:
1280:
1268:
1267:
1266:
1259:
1252:
1245:
1244:
1243:
1222:
1221:
1220:
1219:
1218:
1211:
1190:
1183:
1176:
1168:
1166:
1162:
1161:
1159:
1158:
1151:
1144:
1137:
1136:
1135:
1128:
1125:Micrometeorite
1114:
1107:
1106:
1105:
1102:Changesite-(Y)
1098:
1084:
1081:Wrinkle ridges
1077:
1070:
1069:
1068:
1054:
1053:
1052:
1045:
1038:
1031:
1017:
1016:
1015:
1008:
1001:
987:
980:
979:
978:
964:
963:
962:
948:
947:
946:
945:
944:
930:
918:
917:
916:
909:
897:
890:
883:
875:
873:
865:
864:
862:
861:
854:
853:
852:
845:
838:
831:
817:
816:
815:
808:
807:
806:
799:
792:
785:
784:
783:
776:
755:
748:
734:
733:
732:
725:
724:
723:
709:
702:
701:
700:
679:
676:Lunar distance
671:
669:
663:
662:
655:
653:
651:
650:
649:
648:
634:
627:
624:Magnetic field
620:
619:
618:
604:
597:
590:
582:
580:
574:
573:
568:
565:
564:
557:
556:
549:
542:
534:
527:
526:
513:
499:
497:
494:
491:
490:
467:
450:
449:
447:
444:
442:
439:
438:
437:
432:
425:
422:
421:
420:
410:
403:
401:
393:Giordano Bruno
390:
383:
381:
371:
364:
362:
351:
344:
293:Giordano Bruno
229:
226:
139:thermal imager
15:
9:
6:
4:
3:
2:
1831:
1820:
1817:
1816:
1814:
1798:
1789:
1788:
1785:
1778:
1774:
1771:
1767:
1764:
1763:Double planet
1760:
1757:
1753:
1749:
1744:
1741:
1737:
1734:
1730:
1725:
1721:
1718:
1714:
1711:
1707:
1704:
1700:
1699:
1697:
1693:
1690:
1686:
1683:
1679:
1676:
1672:
1667:
1663:
1660:
1656:
1655:
1653:
1649:
1646:
1645:Moon illusion
1642:
1639:
1635:
1632:
1628:
1625:
1624:Lunar deities
1621:
1620:
1618:
1614:
1607:
1603:
1600:
1596:
1593:
1589:
1588:
1586:
1582:
1575:
1571:
1568:
1564:
1561:
1557:
1554:
1550:
1547:
1543:
1540:
1536:
1533:
1529:
1526:
1522:
1517:
1513:
1512:
1510:
1506:
1503:
1499:
1498:
1496:
1491:
1487:
1480:
1476:
1473:
1472:Lunar station
1469:
1466:
1462:
1459:
1455:
1448:
1444:
1443:
1441:
1437:
1436:
1434:
1430:
1427:
1423:
1420:
1416:
1415:
1413:
1411:
1406:Time-telling
1404:
1397:
1393:
1390:
1386:
1381:
1377:
1376:
1374:
1370:
1367:
1363:
1360:
1356:
1351:
1347:
1344:
1340:
1339:
1337:
1333:
1332:
1330:
1328:
1324:
1317:
1313:
1308:
1304:
1301:
1297:
1296:
1294:
1290:
1285:
1281:
1278:
1274:
1273:
1269:
1264:
1260:
1257:
1253:
1250:
1246:
1241:
1237:
1236:
1234:
1230:
1229:
1227:
1223:
1216:
1212:
1209:
1205:
1204:
1202:
1198:
1197:
1195:
1191:
1188:
1184:
1181:
1177:
1174:
1170:
1169:
1167:
1163:
1156:
1152:
1149:
1145:
1142:
1138:
1133:
1129:
1126:
1122:
1121:
1119:
1115:
1112:
1108:
1103:
1099:
1096:
1092:
1091:
1089:
1085:
1082:
1078:
1075:
1071:
1066:
1062:
1061:
1059:
1055:
1050:
1046:
1043:
1039:
1036:
1032:
1029:
1025:
1024:
1022:
1018:
1013:
1009:
1006:
1002:
999:
995:
994:
992:
988:
985:
981:
976:
972:
971:
969:
965:
960:
956:
955:
953:
949:
942:
938:
937:
935:
931:
928:
924:
923:
919:
914:
910:
907:
903:
902:
898:
895:
891:
888:
884:
881:
877:
876:
874:
872:
866:
859:
858:Lunar station
855:
850:
846:
843:
839:
836:
835:Tidal locking
832:
829:
825:
824:
822:
818:
813:
809:
804:
803:Eclipse cycle
800:
797:
793:
790:
789:Solar eclipse
786:
781:
777:
774:
770:
769:
767:
766:Lunar eclipse
763:
762:
760:
756:
753:
749:
746:
742:
741:
739:
735:
730:
726:
721:
717:
716:
714:
710:
707:
703:
698:
694:
693:
691:
687:
686:
684:
680:
677:
673:
672:
670:
668:
664:
659:
646:
642:
641:
639:
635:
632:
628:
625:
621:
616:
612:
611:
609:
608:Gravity field
605:
602:
598:
595:
591:
588:
584:
583:
581:
575:
571:
566:
562:
555:
550:
548:
543:
541:
536:
535:
532:
524:
520:
519:
514:
511:
507:
506:
501:
500:
486:
481:
480:
471:
465:, Feb 6 2014.
464:
460:
455:
451:
436:
433:
431:
428:
427:
417:
413:
407:
402:
398:
394:
387:
382:
378:
374:
368:
363:
359:
355:
348:
343:
342:
341:
339:
335:
331:
327:
325:
321:
316:
314:
310:
306:
302:
298:
294:
290:
286:
282:
278:
274:
270:
266:
262:
258:
254:
250:
245:
243:
238:
236:
222:
217:
213:
211:
207:
203:
199:
195:
191:
187:
181:
179:
175:
171:
167:
163:
155:
151:
146:
142:
140:
133:
132:
127:
123:
119:
115:
111:
107:
103:
99:
95:
91:
87:
86:impact crater
83:
82:
77:
73:
63:
34:
30:
26:
25:impact crater
21:
1631:Lunar effect
1447:Nodal period
1373:Colonization
1187:Lunar theory
880:Selenography
720:Nodal period
516:
503:
478:
470:
463:Ars Technica
454:
435:Reiner Gamma
391:The rays of
328:
317:
246:
239:
231:
219:The rays of
182:
159:
129:
106:Kamil Crater
79:
75:
69:
54:3.7°N 53.4°E
1740:Moon Treaty
1724:Hollow Moon
1666:Moon rabbit
1638:Earth phase
1440:Lunar month
1327:Exploration
1271:Experiments
1173:Observation
1035:Ray systems
900:Hemispheres
868:Surface and
849:Tidal range
828:Tidal force
631:Sodium tail
615:Hill sphere
249:Aristarchus
210:Lichtenberg
190:cosmic rays
178:lunar maria
112:, and some
57: /
1710:Apollo era
1652:Pareidolia
1410:navigation
1132:Sputtering
1012:Lava tubes
934:South pole
927:North pole
887:Terminator
729:Precession
645:Earthshine
601:Atmosphere
594:Topography
579:properties
441:References
377:Clementine
320:Copernicus
277:Censorinus
253:Copernicus
242:iron oxide
228:Lunar rays
122:atmosphere
76:ray system
1458:Fortnight
1350:Explorers
1307:Apollo 17
1300:Apollo 11
1263:Volcanism
1233:Timescale
1180:Libration
968:Mountains
906:Near side
812:Supermoon
752:Full moon
706:Libration
638:Moonlight
446:Citations
416:Apollo 16
412:South Ray
397:Apollo 11
358:Apollo 15
340:in 1972.
338:Apollo 16
334:South Ray
330:North Ray
265:Dionysius
59:3.7; 53.4
1813:Category
1797:Category
1592:Moonrise
1525:Crescent
1465:Sennight
1380:Moonbase
1336:Missions
1005:Calderas
913:Far side
871:features
759:Eclipses
745:New moon
690:Distance
577:Physical
424:See also
373:Pierazzo
313:Pierazzo
289:far side
198:regolith
170:basaltic
162:infrared
94:diameter
1616:Related
1606:Moonset
1389:Tourism
1366:Landing
1226:Geology
1165:Science
1021:Craters
984:Valleys
570:Outline
496:Sources
379:images)
354:Proclus
305:Jackson
269:Glushko
261:Proclus
118:planets
110:Mercury
45:53°24′E
1574:Tetrad
1490:Phases
1359:Probes
1194:Origin
1141:Quakes
1074:Rilles
1065:swirls
780:Tetrad
738:Syzygy
418:image)
399:image)
360:image)
283:, and
281:Stella
271:, and
257:Kepler
221:Kuiper
202:albedo
166:albedo
154:THEMIS
81:ejecta
42:3°42′N
33:ejecta
23:Fresh
1553:Black
1539:Blood
1516:Names
1494:names
1433:Month
1284:ALSEP
1256:KREEP
1208:Theia
1111:Water
1088:Rocks
998:Domes
952:Maria
921:Poles
713:Nodes
667:Orbit
324:Tycho
297:Necho
285:Linné
273:Tycho
135:'
114:moons
102:Earth
1703:list
1560:Dark
1546:Blue
1509:Full
1408:and
1058:Soil
1028:List
959:List
941:Face
894:Limb
821:Tide
561:Moon
332:and
322:and
309:King
206:lava
192:and
174:lava
150:Mars
126:Mars
98:Moon
90:rays
74:, a
29:Mars
1567:Wet
1502:New
1492:and
485:287
301:Ohm
108:),
70:In
27:on
1815::
461:,
315:.
307:,
303:,
299:,
295:,
279:,
267:,
263:,
259:,
255:,
251:,
141:.
137:s
100:,
66:).
1750:"
1746:"
553:e
546:t
539:v
487:.
414:(
356:(
172:-
104:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
