Knowledge (XXG)

Orbital period

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3634: 1139: 3646: 549: 62: 3608: 3682: 3706: 3658: 3694: 1387:, making it not a merely different approach to the orbit of an object around its parent, but a period of orbital relations with other objects, normally Earth, and their orbits around the Sun. It applies to the elapsed time where planets return to the same kind of phenomenon or location, such as when any planet returns between its consecutive observed 2160:, the synodic period usually means the Sun-synodic period, namely, the time it takes the moon to complete its illumination phases, completing the solar phases for an astronomer on the planet's surface. The Earth's motion does not determine this value for other planets because an Earth observer is not orbited by the moons in question. For example, 3670: 1126:, the strength of universal gravity can be described using some reference material, such as water: the orbital period for an orbit just above the surface of a spherical body of water is 3 hours and 18 minutes. Conversely, this can be used as a kind of "universal" 1452:, is 29.5 mean solar days, since the Moon's phase and position relative to the Sun and Earth repeats after this period. This is longer than the sidereal period of its orbit around Earth, which is 27.3 mean solar days, owing to the motion of Earth around the Sun. 2172:
The concept of synodic period applies not just to the Earth, but also to other planets as well, and the formula for computation is the same as the one given above. Here is a table which lists the synodic periods of some planets relative to each other:
1270:
of the ellipses in which the centers of the bodies move, or equivalently, the semi-major axis of the ellipse in which one body moves, in the frame of reference with the other body at the origin (which is equal to their constant separation for circular
1439:
is also equal to the synodic period. For celestial bodies in the solar system, the synodic period (with respect to Earth and the Sun) differs from the tropical period owing to Earth's motion around the Sun. For example, the synodic period of the
1564:
Periods can be also defined under different specific astronomical definitions that are mostly caused by the small complex external gravitational influences of other celestial objects. Such variations also include the true placement of the
1477:
from the southern to the northern hemisphere. This period differs from the sidereal period because both the orbital plane of the object and the plane of the ecliptic precess with respect to the fixed stars, so their intersection, the
1757: 1430:
is the amount of time that it takes for an object to reappear at the same point in relation to two or more other objects. In common usage, these two objects are typically Earth and the Sun. The time between two successive
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In the special case of perfectly circular orbits, the semimajor axis a is equal to the radius of the orbit, and the orbital velocity is constant and equal to
1680: 1605:
One of the observable characteristics of two bodies which orbit a third body in different orbits, and thus have different orbital periods, is their
1482:, also precesses with respect to the fixed stars. Although the plane of the ecliptic is often held fixed at the position it occupied at a specific 457: 3485: 1176: 860: 3633: 2677: 2656:
Bradley W. Carroll, Dale A. Ostlie. An introduction to modern astrophysics. 2nd edition. Pearson 2007, p. 49 (equation 2.37 simplified).
3545: 565: 229: 298: 1080:
So, for the Earth as the central body (or any other spherically symmetric body with the same mean density, about 5,515 kg/m, e.g.
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An example of this related period description is the repeated cycles for celestial bodies as observed from the Earth's surface, the
3540: 3420: 2839: 3505: 3259: 2557: 1525: 3578: 3217: 3208: 2945: 1520:) is the interval between two alignments of its rotational axis with the Sun, also viewed as two passages of the object at a 119: 676: 1301:
In a parabolic or hyperbolic trajectory, the motion is not periodic, and the duration of the full trajectory is infinite.
769: 3624: 3525: 2995: 583: 1032: 3470: 1505:), the point of its closest approach to the attracting body. It differs from the sidereal period because the object's 1138: 450: 383: 1486:, the orbital plane of the object still precesses, causing the draconitic period to differ from the sidereal period. 3726: 3450: 3277: 987:
When a very small body is in a circular orbit barely above the surface of a sphere of any radius and mean density
3588: 1150:(average of aphelion and perihelion) of some Solar System orbits (crosses denoting Kepler's values) showing that 3573: 3098: 2568: 1643:
has a synodic period of 398.8 days from Earth; thus, Jupiter's opposition occurs once roughly every 13 months.
1578: 378: 293: 1077:
Thus the orbital period in low orbit depends only on the density of the central body, regardless of its size.
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Inversely, for calculating the distance where a body has to orbit in order to have a given orbital period T:
3583: 2891: 2588: 1785: 1632: 1610: 1436: 1388: 249: 3445: 3047: 2967: 2955: 2583: 1636: 1556:), realigning with the Sun before the orbit completes. This cycle of axial precession for Earth, known as 1392: 1294: 667:
For all ellipses with a given semi-major axis the orbital period is the same, regardless of eccentricity.
654: 443: 166: 35: 3568: 3510: 3480: 3268: 3145: 3113: 3083: 3042: 3027: 2906: 351: 186: 94: 3645: 548: 3593: 3415: 3199: 3088: 3057: 2985: 2960: 2935: 2896: 2877: 2832: 2503: 2047: 1432: 224: 181: 171: 99: 2164:'s synodic period is 1.2648 days, 0.18% longer than Deimos's sidereal period of 1.2624 d. 3710: 3455: 3250: 2990: 2119: 2010: 1590: 1570: 1384: 1163: 479: 266: 104: 3736: 3698: 3686: 3650: 3128: 3017: 2915: 1586: 1355: 339: 214: 2693: 3495: 3393: 3323: 3078: 3032: 2950: 2724: 2673: 2157: 1582: 1545: 1483: 1419: 1407: 1316: 254: 191: 70: 2667: 3662: 3475: 3407: 3171: 3133: 3007: 2977: 2930: 2625: 2535: 1814: 1549: 1339: 1081: 424: 373: 138: 82: 525:
For celestial objects in general, the orbital period is determined by a 360° revolution of
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of 398.8 days from Earth; thus, Jupiter's opposition occurs once roughly every 13 months.
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related to the orbits of objects, each of which are often used in the various fields of
3638: 3611: 3563: 3555: 3550: 3435: 3430: 3341: 3332: 2925: 2911: 2887: 2882: 2857: 2539: 2524: 1566: 1400: 756: 573: 401: 317: 311: 159: 153: 148: 1620:, applying to the elapsed time where planets return to the same kind of phenomenon or 1166:, when both orbiting bodies' masses have to be taken into account, the orbital period 3720: 3465: 3460: 3379: 3022: 2940: 2578: 2573: 2161: 2006: 1752:{\displaystyle {\frac {1}{T_{\mathrm {syn} }}}={\frac {1}{T_{1}}}-{\frac {1}{T_{2}}}} 1537: 1517: 1479: 1373: 1351: 1328: 1127: 1108: 1103: â‰ˆ 1,000 kg/m), or bodies with a similar density, e.g. Saturn's moons 526: 406: 239: 196: 1368:
is more particularly about the position of the parent star. It is the basis for the
540:
Periods in astronomy are expressed in units of time, usually hours, days, or years.
61: 3674: 3530: 3440: 3314: 3297: 3155: 3052: 2920: 2782: 2458: 2101: 1498: 1470: 1465: 1415: 1332: 530: 124: 114: 109: 1532:
is slightly shorter than the period for the Sun to complete one circuit along the
2718: 3535: 3370: 3140: 3120: 3037: 2751: 2493: 2344: 2137: 2083: 1553: 1336: 1310: 515: 288: 3103: 2513: 1594: 1574: 1541: 1502: 1369: 981: 969: 961: 854:, it is possible to rewrite the first equation without measuring the mass as: 368: 324: 283: 1589:, etc. Most are investigated by detailed complex astronomical theories using 44:
Time an astronomical object takes to complete one orbit around another object
17: 3520: 2872: 2593: 2065: 1863: 1494: 1411: 519: 507: 487: 2565:– time that it takes to complete one revolution around its axis of rotation 1469:), is the time that elapses between two passages of the object through its 1418:, particularly they must not be confused with other revolving periods like 1533: 1474: 1249:{\displaystyle T=2\pi {\sqrt {\frac {a^{3}}{G\left(M_{1}+M_{2}\right)}}}} 965: 921:{\displaystyle T={\sqrt {{\frac {a^{3}}{r^{3}}}{\frac {3\pi }{G\rho }}}}} 495: 3425: 2817: 2403: 2281: 2029: 1949: 1892: 1640: 1396: 1104: 851: 1631:
for example, when any planet returns between its consecutive observed
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If the orbital periods of the two bodies around the third are called
1422:. Examples of some of the common orbital ones include the following: 973: 491: 1383:
refers not to the orbital relation to the parent star, but to other
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is the time that elapses between two passages of an object at its
1445: 1343: 1085: 976:, completing an orbit every hour. If the same sphere were made of 752: 547: 503: 483: 89: 2694:"Precession of the Earth's Axis - Wolfram Demonstrations Project" 1767:
Table of synodic periods in the Solar System, relative to Earth:
2248: 1987: 1873: 1529: 1441: 977: 744: 511: 2821: 1593:
using precise positional observations of celestial objects via
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Bate, Roger B.; Mueller, Donald D.; White, Jerry E. (1971),
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half a metre in radius would travel at slightly more than 1
1354:. This is the orbital period in an inertial (non-rotating) 1122:
Thus, as an alternative for using a very small number like
748: 984:
above the surface for sustaining the same orbital period.
956:
is the density of the sphere in kilograms per cubic metre.
572:
of two point masses orbiting each other in a circular or
767: 751:, a small body has to orbit at a distance of 1.08  581: 3622: 2672:. Springer Science & Business Media. p. 50. 1683: 1179: 1035: 863: 772: 733:{\displaystyle a={\sqrt{\frac {GMT^{2}}{4\pi ^{2}}}}} 679: 586: 806:{\displaystyle v_{\text{o}}={\sqrt {\frac {GM}{r}}}} 743:
For instance, for completing an orbit every 24 
3494: 3406: 3350: 3286: 3239: 3179: 3170: 3066: 2976: 2865: 2856: 2669:
Satellite Orbits: Models, Methods, and Applications
991:(in kg/m), the above equation simplifies to (since 1751: 1248: 1066: 960:For instance, a small body in circular orbit 10.5 920: 805: 732: 626:{\displaystyle T=2\pi {\sqrt {\frac {a^{3}}{GM}}}} 625: 1067:{\displaystyle T={\sqrt {\frac {3\pi }{G\rho }}}} 522:orbiting a planet or moon to complete one orbit. 2612: 1473:, the point of its orbit where it crosses the 2833: 451: 8: 980:the small body would need to orbit just 6.7 2752:"Questions and Answers - Sten's Space Blog" 1287:is the sum of the masses of the two bodies, 518:. It may also refer to the time it takes a 3607: 3176: 2862: 2840: 2826: 2818: 2666:Oliver Montenbruck, Eberhard Gill (2000). 2175: 1769: 458: 444: 46: 2168:Synodic periods relative to other planets 1741: 1732: 1721: 1712: 1694: 1693: 1684: 1682: 1231: 1218: 1199: 1192: 1178: 1042: 1034: 944:is the orbit's semi-major axis in metres, 896: 888: 878: 872: 870: 862: 824:is the circular orbit's radius in meters, 786: 777: 771: 723: 715: 700: 686: 678: 606: 599: 585: 2489: 2486:Example of orbital periods: binary stars 1763:Examples of sidereal and synodic periods 1137: 3629: 2723:(6th ed.). Springer. p. 145. 2605: 349: 264: 68: 54: 3486:Transposition, docking, and extraction 2777: 2775: 2773: 2771: 2769: 2767: 2765: 34:For the album by Bump of Chicken, see 2717:Hannu Karttunen; et al. (2016). 1327:, determined by a 360° revolution of 663:is the mass of the more massive body. 7: 1674:, their synodic period is given by: 1560:, recurs roughly every 25,772 years. 1364:can be defined in several ways. The 1350:, this period is referred to as the 1497:(in the case of the planets in the 1701: 1698: 1695: 544:Small body orbiting a central body 25: 3546:Kepler's laws of planetary motion 964:above the surface of a sphere of 230:Kepler's laws of planetary motion 3704: 3692: 3680: 3668: 3656: 3644: 3632: 3606: 3541:Interplanetary Transport Network 3421:Collision avoidance (spacecraft) 2613:Bate, Mueller & White (1971) 850:For a perfect sphere of uniform 846:Effect of central body's density 478:) is the amount of time a given 60: 3506:Astronomical coordinate systems 3260:Longitude of the ascending node 2558:Geosynchronous orbit derivation 1158:² is constant (green line) 3579:Retrograde and prograde motion 1170:can be calculated as follows: 1134:Two bodies orbiting each other 1130:if we have a unit of density. 1099:and for a body made of water ( 1088:with 5,243 kg/m) we get: 950:is the gravitational constant, 1: 2806:Fundamentals of Astrodynamics 3526:Equatorial coordinate system 1799: 1609:, which is the time between 1581:by other planets or bodies, 1806: 1792: 1558:precession of the equinoxes 1111:with 984 kg/m we get: 384:Tsiolkovsky rocket equation 3753: 3278:Longitude of the periapsis 2698:demonstrations.wolfram.com 2156:In the case of a planet's 1509:typically advances slowly. 1395:to the Sun. For example, 1308: 838:times (≈ 0.707 times) the 747:around a mass of 100  486:around another object. In 353:Engineering and efficiency 172:Bi-elliptic transfer orbit 33: 26: 3602: 3589:Specific angular momentum 1867: 1778: 1775: 1772: 1639:to the Sun. For example, 1107:with 1,088 kg/m and 1084:with 5,427 kg/m and 2569:Satellite revisit period 1552:(rotate with respect to 1323:typically refers to the 1311:Lunar month § Types 755:from the central body's 490:, it usually applies to 379:Propellant mass fraction 278:Gravitational influences 27:Not to be confused with 3584:Specific orbital energy 2589:List of periodic comets 2177:Orbital period (years) 1372:, and respectively the 1142:Log-log plot of period 845: 556:) and semi-minor axis ( 537:Earth around the Sun. 250:Specific orbital energy 2996:Geostationary transfer 2783:"Planetary Fact Sheet" 2584:Opposition (astronomy) 2545:500,000 years or more 1753: 1444:'s orbit as seen from 1342:. For the case of the 1295:gravitational constant 1250: 1159: 1068: 938:is the sphere's radius 922: 807: 734: 655:gravitational constant 627: 561: 482:takes to complete one 167:Hohmann transfer orbit 3569:Orbital state vectors 3511:Characteristic energy 3481:Trans-lunar injection 3269:Argument of periapsis 2946:Prograde / Retrograde 2907:Hyperbolic trajectory 2756:www.astronomycafe.net 2720:Fundamental Astronomy 1754: 1251: 1141: 1069: 923: 808: 735: 628: 568:, the orbital period 552:The semi-major axis ( 551: 363:Preflight engineering 95:Argument of periapsis 3416:Bi-elliptic transfer 2936:Parabolic trajectory 2627:Density of the Earth 2504:AM Canum Venaticorum 1681: 1346:orbiting around the 1340:projected in the sky 1177: 1033: 861: 828:This corresponds to 770: 677: 584: 419:Propulsive maneuvers 3456:Low-energy transfer 2787:nssdc.gsfc.nasa.gov 2178: 2011:near-Earth asteroid 1591:celestial mechanics 1571:astronomical bodies 1164:celestial mechanics 1146:vs semi-major axis 480:astronomical object 396:Efficiency measures 299:Sphere of influence 268:Celestial mechanics 50:Part of a series on 3451:Inclination change 3099:Distant retrograde 2646:, wolframalpha.com 2630:, wolframalpha.com 2176: 1749: 1587:general relativity 1491:anomalistic period 1448:, relative to the 1435:or two successive 1420:rotational periods 1356:frame of reference 1266:is the sum of the 1246: 1160: 1064: 918: 803: 730: 623: 566:Kepler's Third Law 562: 506:orbiting planets, 215:Dynamical friction 3727:Time in astronomy 3620: 3619: 3594:Two-line elements 3402: 3401: 3324:Eccentric anomaly 3166: 3165: 3033:Orbit of the Moon 2892:Highly elliptical 2679:978-3-540-67280-7 2549: 2548: 2483: 2482: 2154: 2153: 1747: 1727: 1707: 1583:orbital resonance 1567:centre of gravity 1457:draconitic period 1385:celestial objects 1317:celestial objects 1244: 1243: 1062: 1061: 916: 914: 894: 801: 800: 780: 728: 722: 621: 620: 476:revolution period 468: 467: 318:Lagrangian points 255:Vis-viva equation 225:Kepler's equation 72:Orbital mechanics 16:(Redirected from 3744: 3709: 3708: 3707: 3697: 3696: 3695: 3685: 3684: 3683: 3673: 3672: 3661: 3660: 3659: 3649: 3648: 3637: 3636: 3628: 3610: 3609: 3551:Lagrangian point 3446:Hohmann transfer 3391: 3377: 3368: 3359: 3339: 3330: 3321: 3312: 3308: 3304: 3295: 3275: 3266: 3257: 3248: 3228: 3224: 3215: 3206: 3197: 3177: 3146:Heliosynchronous 3095:Lagrange points 3048:Transatmospheric 2863: 2842: 2835: 2828: 2819: 2809: 2791: 2790: 2779: 2760: 2759: 2748: 2742: 2741: 2739: 2737: 2714: 2708: 2707: 2705: 2704: 2690: 2684: 2683: 2663: 2657: 2654: 2648: 2647: 2643:Density of water 2638: 2632: 2631: 2622: 2616: 2610: 2536:Proxima Centauri 2498:Orbital period. 2490: 2179: 1808: 1801: 1794: 1776:Sidereal period 1770: 1758: 1756: 1755: 1750: 1748: 1746: 1745: 1733: 1728: 1726: 1725: 1713: 1708: 1706: 1705: 1704: 1685: 1667: <  1630: 1629: 1625: 1546:equatorial plane 1335:relative to the 1319:in general, the 1255: 1253: 1252: 1247: 1245: 1242: 1241: 1237: 1236: 1235: 1223: 1222: 1204: 1203: 1194: 1193: 1073: 1071: 1070: 1065: 1063: 1060: 1052: 1044: 1043: 1025: 1018: 1015: 1013: 1012: 1009: 1006: 927: 925: 924: 919: 917: 915: 913: 905: 897: 895: 893: 892: 883: 882: 873: 871: 837: 836: 832: 813: 810: 809: 804: 802: 796: 788: 787: 782: 781: 778: 739: 737: 736: 731: 729: 727: 721: 720: 719: 706: 705: 704: 688: 687: 633: 630: 629: 624: 622: 619: 611: 610: 601: 600: 460: 453: 446: 425:Orbital maneuver 374:Payload fraction 354: 335:Lissajous orbits 269: 240:Orbital velocity 187:Hyperbolic orbit 83:Orbital elements 73: 64: 47: 21: 3752: 3751: 3747: 3746: 3745: 3743: 3742: 3741: 3717: 3716: 3715: 3705: 3703: 3693: 3691: 3681: 3679: 3667: 3657: 3655: 3643: 3631: 3623: 3621: 3616: 3598: 3516:Escape velocity 3497: 3490: 3471:Rocket equation 3398: 3390: 3384: 3375: 3366: 3357: 3346: 3337: 3328: 3319: 3310: 3306: 3302: 3293: 3282: 3273: 3264: 3255: 3246: 3235: 3226: 3222: 3218:Semi-minor axis 3213: 3209:Semi-major axis 3204: 3195: 3189: 3162: 3084:Areosynchronous 3068: 3062: 3043:Sun-synchronous 3028:Near-equatorial 2972: 2852: 2846: 2816: 2803: 2800: 2795: 2794: 2781: 2780: 2763: 2750: 2749: 2745: 2735: 2733: 2731: 2716: 2715: 2711: 2702: 2700: 2692: 2691: 2687: 2680: 2665: 2664: 2660: 2655: 2651: 2640: 2639: 2635: 2624: 2623: 2619: 2611: 2607: 2602: 2563:Rotation period 2554: 2508:17.146 minutes 2488: 2170: 1779:Synodic period 1765: 1737: 1717: 1689: 1679: 1678: 1673: 1666: 1659: 1652: 1627: 1623: 1621: 1603: 1554:reference stars 1522:right ascension 1514:tropical period 1507:semi-major axis 1461:draconic period 1406:There are many 1366:tropical period 1362:Orbital periods 1325:sidereal period 1313: 1307: 1305:Related periods 1286: 1279: 1268:semi-major axes 1227: 1214: 1213: 1209: 1205: 1195: 1175: 1174: 1136: 1053: 1045: 1031: 1030: 1016: 1010: 1007: 1004: 1003: 1001: 992: 906: 898: 884: 874: 859: 858: 848: 840:escape velocity 834: 830: 829: 789: 773: 768: 766: 711: 707: 696: 689: 675: 674: 646:semi-major axis 644:is the orbit's 612: 602: 582: 580: 560:) of an ellipse 546: 510:orbiting other 464: 435: 434: 430:Orbit insertion 420: 412: 411: 397: 389: 388: 364: 356: 352: 345: 344: 340:Lyapunov orbits 331: 330: 314: 304: 303: 279: 271: 267: 260: 259: 245:Surface gravity 220:Escape velocity 210: 202: 201: 182:Parabolic orbit 178: 177: 144: 142: 139:two-body orbits 130: 129: 120:Semi-major axis 85: 75: 71: 45: 42: 32: 29:Rotation period 23: 22: 15: 12: 11: 5: 3750: 3748: 3740: 3739: 3734: 3729: 3719: 3718: 3714: 3713: 3701: 3689: 3677: 3665: 3653: 3641: 3618: 3617: 3615: 3614: 3612:List of orbits 3603: 3600: 3599: 3597: 3596: 3591: 3586: 3581: 3576: 3571: 3566: 3564:Orbit equation 3561: 3553: 3548: 3543: 3538: 3533: 3528: 3523: 3518: 3513: 3508: 3502: 3500: 3492: 3491: 3489: 3488: 3483: 3478: 3473: 3468: 3463: 3458: 3453: 3448: 3443: 3438: 3436:Gravity assist 3433: 3431:Delta-v budget 3428: 3423: 3418: 3412: 3410: 3404: 3403: 3400: 3399: 3397: 3396: 3388: 3382: 3373: 3364: 3362:Orbital period 3354: 3352: 3348: 3347: 3345: 3344: 3342:True longitude 3335: 3333:Mean longitude 3326: 3317: 3300: 3290: 3288: 3284: 3283: 3281: 3280: 3271: 3262: 3253: 3243: 3241: 3237: 3236: 3234: 3233: 3220: 3211: 3202: 3192: 3190: 3188: 3187: 3184: 3180: 3174: 3168: 3167: 3164: 3163: 3161: 3160: 3159: 3158: 3150: 3149: 3148: 3143: 3138: 3137: 3136: 3123: 3118: 3117: 3116: 3111: 3106: 3101: 3093: 3092: 3091: 3089:Areostationary 3086: 3081: 3072: 3070: 3064: 3063: 3061: 3060: 3058:Very low Earth 3055: 3050: 3045: 3040: 3035: 3030: 3025: 3020: 3015: 3010: 3005: 3000: 2999: 2998: 2993: 2986:Geosynchronous 2982: 2980: 2974: 2973: 2971: 2970: 2968:Transfer orbit 2965: 2964: 2963: 2958: 2948: 2943: 2938: 2933: 2928: 2926:Lagrange point 2923: 2918: 2909: 2904: 2899: 2894: 2885: 2880: 2875: 2869: 2867: 2860: 2854: 2853: 2848:Gravitational 2847: 2845: 2844: 2837: 2830: 2822: 2815: 2814:External links 2812: 2811: 2810: 2799: 2796: 2793: 2792: 2761: 2743: 2729: 2709: 2685: 2678: 2658: 2649: 2633: 2617: 2604: 2603: 2601: 2598: 2597: 2596: 2591: 2586: 2581: 2576: 2571: 2566: 2560: 2553: 2550: 2547: 2546: 2543: 2540:Alpha Centauri 2532: 2531: 2528: 2525:Alpha Centauri 2521: 2520: 2517: 2510: 2509: 2506: 2500: 2499: 2496: 2487: 2484: 2481: 2480: 2477: 2475: 2473: 2471: 2469: 2467: 2465: 2463: 2461: 2455: 2454: 2451: 2448: 2446: 2444: 2442: 2440: 2438: 2436: 2434: 2428: 2427: 2424: 2421: 2418: 2416: 2414: 2412: 2410: 2408: 2406: 2400: 2399: 2396: 2393: 2390: 2387: 2385: 2383: 2381: 2379: 2377: 2371: 2370: 2367: 2364: 2361: 2358: 2355: 2353: 2351: 2349: 2347: 2341: 2340: 2337: 2334: 2331: 2328: 2325: 2322: 2320: 2318: 2316: 2310: 2309: 2306: 2303: 2300: 2297: 2294: 2291: 2288: 2286: 2284: 2278: 2277: 2274: 2271: 2268: 2265: 2262: 2259: 2256: 2253: 2251: 2245: 2244: 2241: 2238: 2235: 2232: 2229: 2226: 2223: 2220: 2217: 2211: 2210: 2207: 2204: 2201: 2198: 2195: 2192: 2189: 2186: 2183: 2169: 2166: 2152: 2151: 2148: 2145: 2143: 2140: 2134: 2133: 2130: 2127: 2125: 2122: 2116: 2115: 2112: 2109: 2107: 2104: 2098: 2097: 2094: 2091: 2089: 2086: 2080: 2079: 2076: 2073: 2071: 2068: 2062: 2061: 2058: 2055: 2053: 2050: 2044: 2043: 2040: 2037: 2035: 2032: 2026: 2025: 2022: 2019: 2017: 2014: 2003: 2002: 1999: 1996: 1993: 1990: 1984: 1983: 1980: 1977: 1974: 1971: 1965: 1964: 1961: 1958: 1955: 1952: 1946: 1945: 1942: 1939: 1936: 1933: 1927: 1926: 1923: 1920: 1917: 1914: 1908: 1907: 1904: 1901: 1898: 1895: 1889: 1888: 1885: 1882: 1879: 1876: 1870: 1869: 1866: 1860: 1855: 1849: 1848: 1845: 1842: 1839: 1836: 1830: 1829: 1826: 1823: 1820: 1817: 1811: 1810: 1803: 1796: 1789: 1781: 1780: 1777: 1774: 1764: 1761: 1760: 1759: 1744: 1740: 1736: 1731: 1724: 1720: 1716: 1711: 1703: 1700: 1697: 1692: 1688: 1671: 1664: 1657: 1650: 1618:synodic period 1607:synodic period 1602: 1601:Synodic period 1599: 1562: 1561: 1540:) because the 1510: 1487: 1471:ascending node 1453: 1428:synodic period 1401:synodic period 1381:synodic period 1321:orbital period 1306: 1303: 1299: 1298: 1288: 1284: 1277: 1272: 1257: 1256: 1240: 1234: 1230: 1226: 1221: 1217: 1212: 1208: 1202: 1198: 1191: 1188: 1185: 1182: 1135: 1132: 1120: 1119: 1097: 1096: 1075: 1074: 1059: 1056: 1051: 1048: 1041: 1038: 958: 957: 951: 945: 939: 929: 928: 912: 909: 904: 901: 891: 887: 881: 877: 869: 866: 847: 844: 826: 825: 815: 814: 799: 795: 792: 785: 776: 757:center of mass 741: 740: 726: 718: 714: 710: 703: 699: 695: 692: 685: 682: 665: 664: 658: 648: 635: 634: 618: 615: 609: 605: 598: 595: 592: 589: 574:elliptic orbit 545: 542: 472:orbital period 466: 465: 463: 462: 455: 448: 440: 437: 436: 433: 432: 427: 421: 418: 417: 414: 413: 410: 409: 404: 402:Gravity assist 398: 395: 394: 391: 390: 387: 386: 381: 376: 371: 365: 362: 361: 358: 357: 350: 347: 346: 343: 342: 337: 329: 328: 320: 316: 315: 310: 309: 306: 305: 302: 301: 296: 291: 286: 280: 277: 276: 273: 272: 265: 262: 261: 258: 257: 252: 247: 242: 237: 235:Orbital period 232: 227: 222: 217: 211: 208: 207: 204: 203: 200: 199: 197:Decaying orbit 194: 189: 184: 176: 175: 169: 162: 160:Transfer orbit 158: 157: 156: 154:Elliptic orbit 151: 149:Circular orbit 145: 136: 135: 132: 131: 128: 127: 122: 117: 112: 107: 102: 97: 92: 86: 81: 80: 77: 76: 69: 66: 65: 57: 56: 52: 51: 43: 37:Orbital Period 24: 14: 13: 10: 9: 6: 4: 3: 2: 3749: 3738: 3735: 3733: 3730: 3728: 3725: 3724: 3722: 3712: 3702: 3700: 3690: 3688: 3678: 3676: 3671: 3666: 3664: 3654: 3652: 3647: 3642: 3640: 3635: 3630: 3626: 3613: 3605: 3604: 3601: 3595: 3592: 3590: 3587: 3585: 3582: 3580: 3577: 3575: 3572: 3570: 3567: 3565: 3562: 3560: 3559:-body problem 3558: 3554: 3552: 3549: 3547: 3544: 3542: 3539: 3537: 3534: 3532: 3529: 3527: 3524: 3522: 3519: 3517: 3514: 3512: 3509: 3507: 3504: 3503: 3501: 3499: 3493: 3487: 3484: 3482: 3479: 3477: 3474: 3472: 3469: 3467: 3464: 3462: 3461:Oberth effect 3459: 3457: 3454: 3452: 3449: 3447: 3444: 3442: 3439: 3437: 3434: 3432: 3429: 3427: 3424: 3422: 3419: 3417: 3414: 3413: 3411: 3409: 3405: 3395: 3387: 3383: 3381: 3380:Orbital speed 3374: 3372: 3365: 3363: 3356: 3355: 3353: 3349: 3343: 3336: 3334: 3327: 3325: 3318: 3316: 3301: 3299: 3292: 3291: 3289: 3285: 3279: 3272: 3270: 3263: 3261: 3254: 3252: 3245: 3244: 3242: 3238: 3232: 3221: 3219: 3212: 3210: 3203: 3201: 3194: 3193: 3191: 3185: 3182: 3181: 3178: 3175: 3173: 3169: 3157: 3154: 3153: 3151: 3147: 3144: 3142: 3139: 3135: 3134:Earth's orbit 3132: 3131: 3130: 3127: 3126: 3124: 3122: 3119: 3115: 3112: 3110: 3107: 3105: 3102: 3100: 3097: 3096: 3094: 3090: 3087: 3085: 3082: 3080: 3077: 3076: 3074: 3073: 3071: 3065: 3059: 3056: 3054: 3051: 3049: 3046: 3044: 3041: 3039: 3036: 3034: 3031: 3029: 3026: 3024: 3021: 3019: 3016: 3014: 3011: 3009: 3006: 3004: 3001: 2997: 2994: 2992: 2991:Geostationary 2989: 2988: 2987: 2984: 2983: 2981: 2979: 2975: 2969: 2966: 2962: 2959: 2957: 2954: 2953: 2952: 2949: 2947: 2944: 2942: 2939: 2937: 2934: 2932: 2929: 2927: 2924: 2922: 2919: 2917: 2913: 2910: 2908: 2905: 2903: 2900: 2898: 2895: 2893: 2889: 2886: 2884: 2881: 2879: 2876: 2874: 2871: 2870: 2868: 2864: 2861: 2859: 2855: 2851: 2843: 2838: 2836: 2831: 2829: 2824: 2823: 2820: 2813: 2807: 2802: 2801: 2797: 2788: 2784: 2778: 2776: 2774: 2772: 2770: 2768: 2766: 2762: 2757: 2753: 2747: 2744: 2732: 2730:9783662530450 2726: 2722: 2721: 2713: 2710: 2699: 2695: 2689: 2686: 2681: 2675: 2671: 2670: 2662: 2659: 2653: 2650: 2645: 2644: 2637: 2634: 2629: 2628: 2621: 2618: 2615:, p. 33. 2614: 2609: 2606: 2599: 2595: 2592: 2590: 2587: 2585: 2582: 2580: 2579:Sidereal year 2577: 2575: 2574:Sidereal time 2572: 2570: 2567: 2564: 2561: 2559: 2556: 2555: 2551: 2544: 2541: 2537: 2534: 2533: 2529: 2526: 2523: 2522: 2519:12.9075 days 2518: 2515: 2512: 2511: 2507: 2505: 2502: 2501: 2497: 2495: 2492: 2491: 2485: 2478: 2476: 2474: 2472: 2470: 2468: 2466: 2464: 2462: 2460: 2457: 2456: 2452: 2449: 2447: 2445: 2443: 2441: 2439: 2437: 2435: 2433: 2430: 2429: 2425: 2422: 2419: 2417: 2415: 2413: 2411: 2409: 2407: 2405: 2402: 2401: 2397: 2394: 2391: 2388: 2386: 2384: 2382: 2380: 2378: 2376: 2373: 2372: 2368: 2365: 2362: 2359: 2356: 2354: 2352: 2350: 2348: 2346: 2343: 2342: 2338: 2335: 2332: 2329: 2326: 2323: 2321: 2319: 2317: 2315: 2312: 2311: 2307: 2304: 2301: 2298: 2295: 2292: 2289: 2287: 2285: 2283: 2280: 2279: 2275: 2272: 2269: 2266: 2263: 2260: 2257: 2254: 2252: 2250: 2247: 2246: 2242: 2239: 2236: 2233: 2230: 2227: 2224: 2221: 2218: 2216: 2213: 2212: 2208: 2205: 2202: 2199: 2196: 2193: 2190: 2187: 2184: 2181: 2180: 2174: 2167: 2165: 2163: 2159: 2149: 2146: 2144: 2141: 2139: 2136: 2135: 2131: 2128: 2126: 2123: 2121: 2118: 2117: 2113: 2110: 2108: 2105: 2103: 2100: 2099: 2095: 2092: 2090: 2087: 2085: 2082: 2081: 2077: 2074: 2072: 2069: 2067: 2064: 2063: 2059: 2056: 2054: 2051: 2049: 2046: 2045: 2041: 2038: 2036: 2033: 2031: 2028: 2027: 2023: 2020: 2018: 2015: 2012: 2008: 2007:99942 Apophis 2005: 2004: 2000: 1997: 1994: 1991: 1989: 1986: 1985: 1981: 1978: 1975: 1972: 1970: 1967: 1966: 1962: 1959: 1956: 1953: 1951: 1948: 1947: 1943: 1940: 1937: 1934: 1932: 1929: 1928: 1924: 1921: 1918: 1915: 1913: 1910: 1909: 1905: 1902: 1899: 1896: 1894: 1891: 1890: 1886: 1883: 1880: 1877: 1875: 1872: 1871: 1865: 1861: 1859: 1856: 1854: 1851: 1850: 1846: 1843: 1840: 1837: 1835: 1832: 1831: 1827: 1824: 1822:87.9691 days 1821: 1818: 1816: 1813: 1812: 1804: 1797: 1790: 1787: 1783: 1782: 1771: 1768: 1762: 1742: 1738: 1734: 1729: 1722: 1718: 1714: 1709: 1690: 1686: 1677: 1676: 1675: 1670: 1663: 1656: 1649: 1644: 1642: 1638: 1634: 1619: 1614: 1612: 1608: 1600: 1598: 1596: 1592: 1588: 1584: 1580: 1579:perturbations 1576: 1572: 1568: 1559: 1555: 1551: 1547: 1543: 1542:inclined axis 1539: 1538:sidereal year 1535: 1531: 1527: 1523: 1519: 1518:tropical year 1515: 1511: 1508: 1504: 1501:, called the 1500: 1496: 1492: 1488: 1485: 1481: 1480:line of nodes 1476: 1472: 1468: 1467: 1462: 1458: 1454: 1451: 1447: 1443: 1438: 1434: 1429: 1425: 1424: 1423: 1421: 1417: 1413: 1409: 1404: 1402: 1398: 1394: 1390: 1386: 1382: 1377: 1375: 1374:calendar year 1371: 1367: 1363: 1359: 1357: 1353: 1352:sidereal year 1349: 1345: 1341: 1338: 1334: 1330: 1326: 1322: 1318: 1312: 1304: 1302: 1296: 1292: 1289: 1283: 1276: 1273: 1269: 1265: 1262: 1261: 1260: 1238: 1232: 1228: 1224: 1219: 1215: 1210: 1206: 1200: 1196: 1189: 1186: 1183: 1180: 1173: 1172: 1171: 1169: 1165: 1157: 1153: 1149: 1145: 1140: 1133: 1131: 1129: 1125: 1117: 1114: 1113: 1112: 1110: 1106: 1102: 1094: 1091: 1090: 1089: 1087: 1083: 1078: 1057: 1054: 1049: 1046: 1039: 1036: 1029: 1028: 1027: 1024: 1021: 999: 995: 990: 985: 983: 979: 975: 971: 967: 963: 955: 952: 949: 946: 943: 940: 937: 934: 933: 932: 910: 907: 902: 899: 889: 885: 879: 875: 867: 864: 857: 856: 855: 853: 843: 841: 823: 820: 819: 818: 812: 797: 793: 790: 783: 774: 765: 764: 763: 760: 758: 754: 750: 746: 724: 716: 712: 708: 701: 697: 693: 690: 683: 680: 673: 672: 671: 668: 662: 659: 656: 652: 649: 647: 643: 640: 639: 638: 632: 616: 613: 607: 603: 596: 593: 590: 587: 579: 578: 577: 575: 571: 567: 564:According to 559: 555: 550: 543: 541: 538: 536: 532: 528: 523: 521: 517: 513: 509: 505: 501: 498:orbiting the 497: 493: 489: 485: 481: 477: 473: 461: 456: 454: 449: 447: 442: 441: 439: 438: 431: 428: 426: 423: 422: 416: 415: 408: 407:Oberth effect 405: 403: 400: 399: 393: 392: 385: 382: 380: 377: 375: 372: 370: 367: 366: 360: 359: 355: 348: 341: 338: 336: 333: 332: 326: 322: 321: 319: 313: 312:N-body orbits 308: 307: 300: 297: 295: 294:Perturbations 292: 290: 287: 285: 282: 281: 275: 274: 270: 263: 256: 253: 251: 248: 246: 243: 241: 238: 236: 233: 231: 228: 226: 223: 221: 218: 216: 213: 212: 206: 205: 198: 195: 193: 190: 188: 185: 183: 180: 179: 173: 170: 168: 164: 163: 161: 155: 152: 150: 147: 146: 140: 134: 133: 126: 123: 121: 118: 116: 115:Orbital nodes 113: 111: 108: 106: 103: 101: 98: 96: 93: 91: 88: 87: 84: 79: 78: 74: 67: 63: 59: 58: 55:Astrodynamics 53: 49: 48: 40: 38: 30: 19: 18:Synodic cycle 3711:Solar System 3574:Perturbation 3556: 3531:Ground track 3441:Gravity turn 3392:   3385: 3378:   3369:   3361: 3360:   3340:   3331:   3322:   3315:True anomaly 3313:   3298:Mean anomaly 3296:   3276:   3267:   3258:   3249:   3229:   3216:   3207:   3200:Eccentricity 3198:   3156:Lunar cycler 3129:Heliocentric 3069:other points 3018:Medium Earth 2916:Non-inclined 2805: 2798:Bibliography 2786: 2755: 2746: 2734:. Retrieved 2719: 2712: 2701:. Retrieved 2697: 2688: 2668: 2661: 2652: 2642: 2636: 2626: 2620: 2608: 2530:79.91 years 2459:50000 Quaoar 2182:Relative to 2171: 2155: 2102:50000 Quaoar 1969:134340 Pluto 1857: 1766: 1668: 1661: 1654: 1647: 1645: 1633:conjunctions 1617: 1615: 1611:conjunctions 1606: 1604: 1569:between two 1563: 1557: 1528:. One Earth 1516:of Earth (a 1513: 1499:Solar System 1490: 1466:nodal period 1464: 1460: 1456: 1437:conjunctions 1427: 1416:astrophysics 1405: 1389:conjunctions 1380: 1378: 1365: 1361: 1360: 1324: 1320: 1314: 1300: 1290: 1281: 1274: 1263: 1258: 1167: 1161: 1155: 1151: 1147: 1143: 1128:unit of time 1123: 1121: 1118:= 3.30 hours 1115: 1100: 1098: 1095:= 1.41 hours 1092: 1079: 1076: 1022: 1019: 997: 993: 988: 986: 959: 953: 947: 941: 935: 930: 849: 827: 821: 816: 761: 742: 669: 666: 660: 650: 641: 636: 569: 563: 557: 553: 539: 534: 524: 516:binary stars 475: 471: 469: 234: 192:Radial orbit 143:eccentricity 125:True anomaly 110:Mean anomaly 100:Eccentricity 36: 3699:Outer space 3687:Spaceflight 3651:Mathematics 3536:Hill sphere 3371:Mean motion 3251:Inclination 3240:Orientation 3141:Mars cycler 3079:Areocentric 2951:Synchronous 2736:December 7, 2494:Binary star 2345:2060 Chiron 2138:90377 Sedna 2120:136199 Eris 2084:2060 Chiron 1995:27.32 days 1841:224.7 days 1637:oppositions 1433:oppositions 1393:oppositions 1337:fixed stars 1331:around its 529:around its 325:Halo orbits 289:Hill sphere 105:Inclination 3721:Categories 3476:Rendezvous 3172:Parameters 3008:High Earth 2978:Geocentric 2931:Osculating 2888:Elliptical 2703:2019-02-10 2514:Beta Lyrae 1864:solar days 1862:365.25636 1660:, so that 1595:astrometry 1575:barycenter 1512:Also, the 1503:perihelion 1370:solar year 1309:See also: 508:exoplanets 369:Mass ratio 284:Barycenter 3737:Durations 3663:Astronomy 3521:Ephemeris 3498:mechanics 3408:Maneuvers 3351:Variation 3114:Libration 3109:Lissajous 3013:Low Earth 3003:Graveyard 2902:Horseshoe 2594:Leap year 2066:10 Hygiea 1819:0.240846 1730:− 1495:periapsis 1412:astronomy 1190:π 1058:ρ 1050:π 911:ρ 903:π 713:π 597:π 520:satellite 496:asteroids 488:astronomy 209:Equations 137:Types of 3287:Position 2912:Inclined 2883:Circular 2552:See also 2200:Neptune 2188:Jupiter 2024:2,837.6 2001:29.5306 1635:with or 1622:location 1534:ecliptic 1475:ecliptic 1391:with or 1329:one body 1271:orbits), 1000: = 996: = 966:tungsten 527:one body 3639:Physics 3625:Portals 3496:Orbital 3466:Phasing 3426:Delta-v 3231:Apsides 3225:,  3023:Molniya 2941:Parking 2878:Capture 2866:General 2808:, Dover 2450:1810.4 2404:Neptune 2282:Jupiter 2206:Quaoar 2197:Uranus 2194:Chiron 2191:Saturn 2150:365.3 2147:1.0001 2048:1 Ceres 2030:4 Vesta 1998:0.0809 1992:0.0748 1976:90,560 1957:59,800 1950:Neptune 1938:30,589 1919:10,747 1893:Jupiter 1828:115.88 1815:Mercury 1773:Object 1641:Jupiter 1628:  1624:  1550:precess 1548:slowly 1408:periods 1397:Jupiter 1333:primary 1293:is the 1259:where: 1154:³/ 1105:Iapetus 1082:Mercury 1014:⁠ 1002:⁠ 931:where: 852:density 833:⁄ 817:where: 653:is the 637:where: 531:primary 492:planets 39:(album) 3732:Orbits 3152:Other 3053:Tundra 2921:Kepler 2897:Escape 2850:orbits 2727:  2676:  2479:594.2 2453:447.4 2426:234.0 2423:386.1 2420:490.8 2398:98.93 2395:118.7 2392:127.0 2389:171.4 2375:Uranus 2369:55.44 2366:61.14 2363:63.28 2360:72.65 2357:126.1 2339:31.11 2336:32.82 2333:33.43 2330:35.87 2327:45.37 2324:70.87 2314:Saturn 2308:12.12 2305:12.37 2302:12.46 2299:12.78 2296:13.81 2293:15.51 2290:19.85 2276:1.887 2273:1.893 2270:1.895 2267:1.903 2264:1.924 2261:1.954 2258:2.009 2255:2.236 2243:557.0 2240:287.5 2237:248.1 2234:164.8 2231:84.01 2228:50.42 2225:29.46 2222:11.86 2219:1.881 2203:Pluto 2162:Deimos 2142:12050 2132:365.9 2129:1.002 2114:366.5 2111:1.003 2106:287.5 2096:372.6 2093:1.020 2088:50.42 2078:445.4 2075:1.219 2070:5.557 2060:466.7 2057:1.278 2052:4.600 2042:504.0 2039:1.380 2034:3.629 2021:7.769 2016:0.886 1982:366.7 1979:1.004 1973:248.1 1963:367.5 1960:1.006 1954:164.8 1944:369.7 1941:1.012 1935:84.01 1931:Uranus 1925:378.1 1922:1.035 1916:29.46 1912:Saturn 1906:398.9 1903:1.092 1897:11.86 1887:779.9 1884:2.135 1881:687.0 1878:1.881 1847:583.9 1844:1.599 1838:0.615 1825:0.317 1459:(also 1399:has a 1109:Tethys 753:meters 474:(also 3675:Stars 3394:Epoch 3183:Shape 3121:Lunar 3075:Mars 3067:About 3038:Polar 2858:Types 2600:Notes 2432:Pluto 2209:Eris 2185:Mars 1900:4331 1853:Earth 1834:Venus 1484:epoch 1446:Earth 1344:Earth 1086:Venus 745:hours 514:, or 512:stars 504:moons 484:orbit 90:Apsis 3186:Size 3125:Sun 3104:Halo 2956:semi 2738:2018 2725:ISBN 2674:ISBN 2249:Mars 2158:moon 2124:557 1988:Moon 1874:Mars 1653:and 1544:and 1530:year 1526:0 hr 1489:The 1455:The 1442:Moon 1426:The 1414:and 1379:The 1315:For 978:lead 576:is: 535:e.g. 470:The 2961:sub 2873:Box 2542:AB 2527:AB 2516:AB 2215:Sun 1577:), 1536:(a 1524:of 1463:or 1450:Sun 1348:Sun 1162:In 500:Sun 494:or 141:by 3723:: 3309:, 3305:, 2914:/ 2890:/ 2785:. 2764:^ 2754:. 2696:. 2538:– 2013:) 1868:— 1809:) 1802:) 1800:yr 1795:) 1788:) 1786:yr 1613:. 1597:. 1585:, 1376:. 1358:. 1280:+ 1026:) 998:VĪ 982:mm 970:mm 962:cm 842:. 835:√2 759:. 749:kg 533:, 502:, 3627:: 3557:n 3389:0 3386:t 3376:v 3367:n 3358:T 3338:l 3329:L 3320:E 3311:f 3307:θ 3303:ÎŊ 3294:M 3274:Ī– 3265:Ī‰ 3256:Ί 3247:i 3227:q 3223:Q 3214:b 3205:a 3196:e 2841:e 2834:t 2827:v 2789:. 2758:. 2740:. 2706:. 2682:. 2009:( 1858:1 1807:d 1805:( 1798:( 1793:d 1791:( 1784:( 1743:2 1739:T 1735:1 1723:1 1719:T 1715:1 1710:= 1702:n 1699:y 1696:s 1691:T 1687:1 1672:2 1669:T 1665:1 1662:T 1658:2 1655:T 1651:1 1648:T 1626:— 1573:( 1297:. 1291:G 1285:2 1282:M 1278:1 1275:M 1264:a 1239:) 1233:2 1229:M 1225:+ 1220:1 1216:M 1211:( 1207:G 1201:3 1197:a 1187:2 1184:= 1181:T 1168:T 1156:T 1152:a 1148:a 1144:T 1124:G 1116:T 1101:Ī 1093:T 1055:G 1047:3 1040:= 1037:T 1023:Ī 1020:a 1017:Ī€ 1011:3 1008:/ 1005:4 994:M 989:Ī 974:s 972:/ 954:Ī 948:G 942:a 936:r 908:G 900:3 890:3 886:r 880:3 876:a 868:= 865:T 831:1 822:r 798:r 794:M 791:G 784:= 779:o 775:v 725:3 717:2 709:4 702:2 698:T 694:M 691:G 684:= 681:a 661:M 657:, 651:G 642:a 617:M 614:G 608:3 604:a 594:2 591:= 588:T 570:T 558:b 554:a 459:e 452:t 445:v 327:) 323:( 174:) 165:( 41:. 31:. 20:)

Index

Synodic cycle
Rotation period
Orbital Period (album)

Orbital mechanics
Orbital elements
Apsis
Argument of periapsis
Eccentricity
Inclination
Mean anomaly
Orbital nodes
Semi-major axis
True anomaly
two-body orbits
Circular orbit
Elliptic orbit
Transfer orbit
Hohmann transfer orbit
Bi-elliptic transfer orbit
Parabolic orbit
Hyperbolic orbit
Radial orbit
Decaying orbit
Dynamical friction
Escape velocity
Kepler's equation
Kepler's laws of planetary motion
Orbital period
Orbital velocity

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