G8V Star System Generated (Seed: 1766928361)
Star Details
Spectral Class: G7V
Temperature: 5,400 K
Mass: 0.95 sol
Luminosity: 0.84 lux
Habitable Zone (HZ)
Inner Boundary: 0.87 AU
Outer Boundary: 1.26 AU
Physical Limits
Snow Line: 4.4 AU
Max System Radius: 19.5 AU
Planetary System (9 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.64 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.45
Radius: 0.73
Gravity: 0.84 G
Time & Orbit
Eccentricity (e): 0.195
Orbit Range: 0.52 AU - 0.76 AU
Year: 192 Days
Day: 38.6 Hours
Environment
Temp: 193 °C
Axial Tilt: 22.7 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (1)
Outer Limit: 102,302,916 km
- M1: 167,998 km (0.063 R)
Planet 2 - Terrestrial
Semi-Major Axis: 1.08 AU
Status: HZ
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 3.02
Radius: 1.56
Gravity: 1.24 G
Time & Orbit
Eccentricity (e): 0.135
Orbit Range: 0.93 AU - 1.23 AU
Year: 421 Days
Day: 40.6 Hours
Environment
Temp: 13 °C
Axial Tilt: 35.6 °
Atmosphere: Nâ‚‚, Oâ‚‚
Biome: Oceanic/Continental
Planet 3 - Terrestrial
Semi-Major Axis: 1.28 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.12
Radius: 1.35
Gravity: 1.16 G
Time & Orbit
Eccentricity (e): 0.232
Orbit Range: 0.98 AU - 1.58 AU
Year: 543 Days
Day: 47.6 Hours
Environment
Temp: -31 °C
Axial Tilt: 32.6 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 102,302,916 km
- M1: 484,398 km (0.096 R)
Planet 4 - Terrestrial
Semi-Major Axis: 2.08 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 3.64
Radius: 1.68
Gravity: 1.29 G
Time & Orbit
Eccentricity (e): 0.037
Orbit Range: 2 AU - 2.16 AU
Year: 1124 Days
Day: 36.7 Hours
Environment
Temp: -74 °C
Axial Tilt: 19.5 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 5 - Gas Giant
Semi-Major Axis: 7.12 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 76.2
Radius: 11.3
Gravity: 0.6 G
Time & Orbit
Eccentricity (e): 0.087
Orbit Range: 6.5 AU - 7.74 AU
Year: 7119 Days
Day: 9 Hours
Environment
Temp: -170 °C
Axial Tilt: 43.9 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (52)
Outer Limit: 102,302,916 km
- M1: 200,012 km (0.108 R)
- M2: 375,790 km (0.112 R)
- M3: 449,841 km (0.081 R)
- M4: 522,695 km (0.119 R)
- M5: 666,159 km (0.097 R)
- M6: 898,784 km (0.119 R)
- M7: 1,025,194 km (0.106 R)
- M8: 1,106,276 km (0.053 R)
- M9: 1,189,602 km (0.054 R)
- M10: 1,307,934 km (0.113 R)
- M11: 2,325,349 km (0.056 R)
- M12: 2,915,662 km (0.106 R)
- M13: 3,197,804 km (0.103 R)
- M14: 3,273,501 km (0.092 R)
- M15: 3,629,693 km (0.107 R)
- M16: 4,806,879 km (0.119 R)
- M17: 5,961,475 km (0.107 R)
- M18: 6,396,805 km (0.114 R)
- M19: 6,647,381 km (0.101 R)
- M20: 6,725,172 km (0.08 R)
- M21: 7,078,971 km (0.1 R)
- M22: 7,278,086 km (0.12 R)
- M23: 7,479,146 km (0.114 R)
- M24: 7,600,619 km (0.112 R)
- M25: 8,554,156 km (0.026 R)
- M26: 8,745,043 km (0.102 R)
- M27: 9,023,444 km (0.073 R)
- M28: 9,787,441 km (0.067 R)
- M29: 9,876,003 km (0.109 R)
- M30: 10,009,594 km (0.089 R)
- M31: 10,188,363 km (0.082 R)
- M32: 10,617,559 km (0.08 R)
- M33: 10,754,292 km (0.114 R)
- M34: 11,052,590 km (0.092 R)
- M35: 11,680,901 km (0.04 R)
- M36: 11,798,634 km (0.059 R)
- M37: 12,201,502 km (0.085 R)
- M38: 12,368,752 km (0.076 R)
- M39: 12,705,497 km (0.111 R)
- M40: 13,142,921 km (0.09 R)
- M41: 13,240,908 km (0.113 R)
- M42: 13,486,697 km (0.115 R)
- M43: 13,634,799 km (0.064 R)
- M44: 13,808,482 km (0.092 R)
- M45: 13,932,798 km (0.113 R)
- M46: 14,132,810 km (0.08 R)
- M47: 14,484,814 km (0.106 R)
- M48: 14,865,391 km (0.12 R)
- M49: 15,636,119 km (0.085 R)
- M50: 16,790,117 km (0.07 R)
- M51: 17,377,438 km (0.114 R)
- M52: 18,380,342 km (0.078 R)
Planet 6 - Gas Giant
Semi-Major Axis: 9.1 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 737.4
Radius: 9.3
Gravity: 8.53 G
Time & Orbit
Eccentricity (e): 0.224
Orbit Range: 7.06 AU - 11.14 AU
Year: 10287 Days
Day: 13.3 Hours
Environment
Temp: -177 °C
Axial Tilt: 47.5 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (89)
Outer Limit: 102,302,916 km
- M1: 138,827 km (0.109 R)
- M2: 325,076 km (0.095 R)
- M3: 849,716 km (0.101 R)
- M4: 981,811 km (0.103 R)
- M5: 1,040,603 km (0.053 R)
- M6: 1,141,581 km (0.099 R)
- M7: 1,671,457 km (0.077 R)
- M8: 1,766,601 km (0.054 R)
- M9: 2,988,217 km (0.064 R)
- M10: 3,075,433 km (0.077 R)
- M11: 3,163,546 km (0.119 R)
- M12: 3,463,191 km (0.111 R)
- M13: 3,961,651 km (0.086 R)
- M14: 4,057,693 km (0.086 R)
- M15: 4,853,553 km (0.082 R)
- M16: 4,956,477 km (0.075 R)
- M17: 5,025,441 km (0.05 R)
- M18: 5,304,591 km (0.064 R)
- M19: 6,660,845 km (0.117 R)
- M20: 7,006,267 km (0.085 R)
- M21: 8,036,996 km (0.096 R)
- M22: 8,322,429 km (0.036 R)
- M23: 8,445,847 km (0.037 R)
- M24: 8,569,864 km (0.116 R)
- M25: 8,819,842 km (0.074 R)
- M26: 9,072,064 km (0.112 R)
- M27: 10,017,373 km (0.117 R)
- M28: 10,192,701 km (0.089 R)
- M29: 10,457,490 km (0.112 R)
- M30: 10,813,981 km (0.059 R)
- M31: 11,174,662 km (0.071 R)
- M32: 11,493,455 km (0.09 R)
- M33: 11,676,862 km (0.094 R)
- M34: 12,000,442 km (0.066 R)
- M35: 12,280,040 km (0.111 R)
- M36: 13,227,593 km (0.087 R)
- M37: 13,807,435 km (0.046 R)
- M38: 15,142,296 km (0.07 R)
- M39: 15,444,484 km (0.108 R)
- M40: 15,647,189 km (0.114 R)
- M41: 15,952,668 km (0.116 R)
- M42: 16,363,165 km (0.072 R)
- M43: 16,933,133 km (0.094 R)
- M44: 17,615,299 km (0.059 R)
- M45: 18,092,815 km (0.047 R)
- M46: 19,496,043 km (0.097 R)
- M47: 19,660,152 km (0.034 R)
- M48: 19,989,866 km (0.092 R)
- M49: 20,599,028 km (0.09 R)
- M50: 20,989,928 km (0.098 R)
- M51: 21,383,220 km (0.111 R)
- M52: 21,835,754 km (0.096 R)
- M53: 22,120,140 km (0.057 R)
- M54: 23,444,230 km (0.109 R)
- M55: 23,910,826 km (0.108 R)
- M56: 24,086,604 km (0.11 R)
- M57: 25,807,577 km (0.102 R)
- M58: 26,956,489 km (0.098 R)
- M59: 28,369,441 km (0.096 R)
- M60: 28,431,524 km (0.103 R)
- M61: 30,438,679 km (0.104 R)
- M62: 30,692,696 km (0.11 R)
- M63: 30,820,004 km (0.052 R)
- M64: 31,395,208 km (0.071 R)
- M65: 32,296,834 km (0.113 R)
- M66: 32,361,610 km (0.073 R)
- M67: 32,620,863 km (0.117 R)
- M68: 33,665,206 km (0.043 R)
- M69: 34,654,197 km (0.114 R)
- M70: 34,919,434 km (0.098 R)
- M71: 35,318,711 km (0.108 R)
- M72: 35,987,563 km (0.066 R)
- M73: 36,054,732 km (0.094 R)
- M74: 36,458,347 km (0.109 R)
- M75: 37,541,735 km (0.07 R)
- M76: 38,087,468 km (0.075 R)
- M77: 38,155,835 km (0.081 R)
- M78: 39,601,548 km (0.059 R)
- M79: 40,087,592 km (0.115 R)
- M80: 40,226,718 km (0.092 R)
- M81: 41,205,537 km (0.12 R)
- M82: 41,557,092 km (0.106 R)
- M83: 41,698,013 km (0.101 R)
- M84: 42,404,713 km (0.104 R)
- M85: 42,475,623 km (0.074 R)
- M86: 44,692,813 km (0.089 R)
- M87: 44,837,175 km (0.085 R)
- M88: 46,216,168 km (0.103 R)
- M89: 49,686,689 km (0.106 R)
Planet 7 - Gas Giant
Semi-Major Axis: 9.34 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 520
Radius: 9
Gravity: 6.42 G
Time & Orbit
Eccentricity (e): 0.037
Orbit Range: 8.99 AU - 9.69 AU
Year: 10697 Days
Day: 12 Hours
Environment
Temp: -180 °C
Axial Tilt: 39.5 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (83)
Outer Limit: 102,302,916 km
- M1: 133,142 km (0.111 R)
- M2: 292,314 km (0.057 R)
- M3: 668,553 km (0.091 R)
- M4: 903,122 km (0.077 R)
- M5: 1,144,274 km (0.091 R)
- M6: 1,468,901 km (0.056 R)
- M7: 1,598,154 km (0.039 R)
- M8: 2,128,179 km (0.105 R)
- M9: 3,059,127 km (0.097 R)
- M10: 3,683,399 km (0.068 R)
- M11: 3,771,662 km (0.049 R)
- M12: 3,920,212 km (0.041 R)
- M13: 4,691,838 km (0.07 R)
- M14: 5,342,439 km (0.114 R)
- M15: 6,160,291 km (0.071 R)
- M16: 6,230,153 km (0.097 R)
- M17: 6,335,470 km (0.085 R)
- M18: 6,835,127 km (0.068 R)
- M19: 7,683,496 km (0.113 R)
- M20: 8,760,451 km (0.09 R)
- M21: 9,116,644 km (0.076 R)
- M22: 9,518,015 km (0.039 R)
- M23: 10,213,645 km (0.101 R)
- M24: 11,957,657 km (0.053 R)
- M25: 12,089,004 km (0.102 R)
- M26: 12,176,668 km (0.109 R)
- M27: 12,397,026 km (0.099 R)
- M28: 12,485,438 km (0.101 R)
- M29: 12,796,901 km (0.117 R)
- M30: 13,020,849 km (0.081 R)
- M31: 13,110,757 km (0.088 R)
- M32: 14,718,336 km (0.095 R)
- M33: 14,952,906 km (0.086 R)
- M34: 15,760,285 km (0.118 R)
- M35: 15,904,198 km (0.097 R)
- M36: 16,048,560 km (0.118 R)
- M37: 16,435,570 km (0.06 R)
- M38: 18,366,579 km (0.079 R)
- M39: 18,771,391 km (0.104 R)
- M40: 19,230,507 km (0.102 R)
- M41: 19,744,825 km (0.077 R)
- M42: 20,003,778 km (0.094 R)
- M43: 20,159,659 km (0.091 R)
- M44: 20,629,696 km (0.108 R)
- M45: 21,262,046 km (0.09 R)
- M46: 21,954,236 km (0.072 R)
- M47: 22,437,885 km (0.114 R)
- M48: 22,599,900 km (0.118 R)
- M49: 23,634,668 km (0.114 R)
- M50: 23,799,525 km (0.093 R)
- M51: 25,976,623 km (0.109 R)
- M52: 27,520,922 km (0.096 R)
- M53: 27,752,200 km (0.115 R)
- M54: 27,868,139 km (0.079 R)
- M55: 28,100,314 km (0.081 R)
- M56: 28,216,702 km (0.103 R)
- M57: 28,275,045 km (0.082 R)
- M58: 28,391,581 km (0.064 R)
- M59: 28,859,673 km (0.071 R)
- M60: 29,685,005 km (0.095 R)
- M61: 30,817,311 km (0.067 R)
- M62: 30,937,288 km (0.069 R)
- M63: 31,057,565 km (0.071 R)
- M64: 31,298,268 km (0.085 R)
- M65: 31,358,706 km (0.086 R)
- M66: 32,878,770 km (0.05 R)
- M67: 33,185,595 km (0.096 R)
- M68: 35,297,618 km (0.109 R)
- M69: 35,800,865 km (0.119 R)
- M70: 35,927,125 km (0.075 R)
- M71: 36,496,794 km (0.106 R)
- M72: 36,941,848 km (0.12 R)
- M73: 38,610,911 km (0.074 R)
- M74: 39,064,492 km (0.064 R)
- M75: 39,585,093 km (0.115 R)
- M76: 39,911,515 km (0.104 R)
- M77: 40,830,495 km (0.031 R)
- M78: 41,424,847 km (0.096 R)
- M79: 41,889,199 km (0.067 R)
- M80: 41,955,620 km (0.077 R)
- M81: 42,756,119 km (0.115 R)
- M82: 44,847,048 km (0.067 R)
- M83: 45,255,600 km (0.1 R)
Planet 8 - Ice Giant
Semi-Major Axis: 17.53 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 61.8
Radius: 6
Gravity: 1.72 G
Time & Orbit
Eccentricity (e): 0.002
Orbit Range: 17.49 AU - 17.57 AU
Year: 27504 Days
Day: 18.1 Hours
Environment
Temp: -204 °C
Axial Tilt: 16.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (72)
Outer Limit: 102,302,916 km
- M1: 374,443 km (0.036 R)
- M2: 517,609 km (0.116 R)
- M3: 617,989 km (0.097 R)
- M4: 905,516 km (0.112 R)
- M5: 974,780 km (0.08 R)
- M6: 1,632,562 km (0.074 R)
- M7: 2,257,731 km (0.095 R)
- M8: 2,473,152 km (0.076 R)
- M9: 2,695,305 km (0.113 R)
- M10: 3,079,771 km (0.071 R)
- M11: 3,372,534 km (0.079 R)
- M12: 3,899,268 km (0.101 R)
- M13: 5,120,885 km (0.032 R)
- M14: 5,435,639 km (0.112 R)
- M15: 5,691,900 km (0.099 R)
- M16: 6,927,728 km (0.054 R)
- M17: 7,275,543 km (0.111 R)
- M18: 8,206,341 km (0.119 R)
- M19: 8,352,947 km (0.098 R)
- M20: 8,685,802 km (0.062 R)
- M21: 9,710,099 km (0.046 R)
- M22: 9,787,441 km (0.071 R)
- M23: 10,453,600 km (0.054 R)
- M24: 10,493,243 km (0.067 R)
- M25: 10,812,186 km (0.065 R)
- M26: 11,418,656 km (0.109 R)
- M27: 12,161,110 km (0.114 R)
- M28: 12,454,023 km (0.083 R)
- M29: 12,496,060 km (0.06 R)
- M30: 12,580,283 km (0.04 R)
- M31: 13,605,478 km (0.104 R)
- M32: 13,953,143 km (0.046 R)
- M33: 14,128,023 km (0.097 R)
- M34: 14,746,012 km (0.084 R)
- M35: 15,508,362 km (0.043 R)
- M36: 16,421,358 km (0.083 R)
- M37: 16,652,337 km (0.102 R)
- M38: 17,728,844 km (0.1 R)
- M39: 17,918,235 km (0.069 R)
- M40: 18,442,874 km (0.103 R)
- M41: 18,634,808 km (0.09 R)
- M42: 18,972,451 km (0.115 R)
- M43: 19,069,241 km (0.101 R)
- M44: 19,948,128 km (0.092 R)
- M45: 20,790,214 km (0.104 R)
- M46: 22,765,505 km (0.08 R)
- M47: 23,437,199 km (0.1 R)
- M48: 23,853,829 km (0.09 R)
- M49: 23,958,249 km (0.101 R)
- M50: 25,490,879 km (0.114 R)
- M51: 25,597,841 km (0.072 R)
- M52: 25,811,916 km (0.107 R)
- M53: 26,620,492 km (0.066 R)
- M54: 26,728,801 km (0.116 R)
- M55: 27,546,653 km (0.077 R)
- M56: 27,766,262 km (0.071 R)
- M57: 29,206,890 km (0.099 R)
- M58: 29,936,329 km (0.117 R)
- M59: 29,992,727 km (0.109 R)
- M60: 32,276,040 km (0.12 R)
- M61: 32,797,388 km (0.059 R)
- M62: 33,030,013 km (0.078 R)
- M63: 33,204,893 km (0.114 R)
- M64: 34,555,463 km (0.116 R)
- M65: 37,370,595 km (0.064 R)
- M66: 38,162,118 km (0.095 R)
- M67: 38,345,525 km (0.113 R)
- M68: 38,590,566 km (0.095 R)
- M69: 39,452,399 km (0.114 R)
- M70: 39,885,784 km (0.079 R)
- M71: 41,257,746 km (0.109 R)
- M72: 41,697,564 km (0.049 R)
Planet 9 - Ice Giant
Semi-Major Axis: 18.87 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 705.8
Radius: 6.7
Gravity: 15.72 G
Time & Orbit
Eccentricity (e): 0.12
Orbit Range: 16.61 AU - 21.13 AU
Year: 30718 Days
Day: 24 Hours
Environment
Temp: -200 °C
Axial Tilt: 22.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (92)
Outer Limit: 102,302,916 km
- M1: 143,165 km (0.116 R)
- M2: 536,757 km (0.091 R)
- M3: 840,590 km (0.112 R)
- M4: 994,826 km (0.094 R)
- M5: 1,661,434 km (0.096 R)
- M6: 2,058,168 km (0.116 R)
- M7: 2,310,090 km (0.048 R)
- M8: 2,982,383 km (0.089 R)
- M9: 4,600,883 km (0.078 R)
- M10: 4,655,187 km (0.103 R)
- M11: 5,097,398 km (0.105 R)
- M12: 5,266,743 km (0.049 R)
- M13: 5,380,587 km (0.113 R)
- M14: 6,381,546 km (0.113 R)
- M15: 6,503,169 km (0.092 R)
- M16: 7,954,717 km (0.106 R)
- M17: 8,615,940 km (0.056 R)
- M18: 9,021,200 km (0.044 R)
- M19: 9,226,149 km (0.066 R)
- M20: 10,631,322 km (0.101 R)
- M21: 10,775,385 km (0.106 R)
- M22: 11,432,120 km (0.115 R)
- M23: 14,027,792 km (0.063 R)
- M24: 14,824,551 km (0.053 R)
- M25: 16,295,247 km (0.098 R)
- M26: 16,712,027 km (0.03 R)
- M27: 16,879,726 km (0.117 R)
- M28: 17,470,937 km (0.11 R)
- M29: 18,935,051 km (0.089 R)
- M30: 19,903,249 km (0.093 R)
- M31: 19,991,960 km (0.112 R)
- M32: 20,438,061 km (0.052 R)
- M33: 22,347,080 km (0.052 R)
- M34: 22,995,885 km (0.119 R)
- M35: 23,182,434 km (0.041 R)
- M36: 24,407,042 km (0.095 R)
- M37: 25,075,296 km (0.117 R)
- M38: 25,171,188 km (0.08 R)
- M39: 31,870,630 km (0.065 R)
- M40: 33,547,023 km (0.087 R)
- M41: 33,970,684 km (0.115 R)
- M42: 34,395,991 km (0.114 R)
- M43: 34,502,655 km (0.097 R)
- M44: 34,823,093 km (0.065 R)
- M45: 35,682,683 km (0.076 R)
- M46: 36,440,396 km (0.058 R)
- M47: 36,657,911 km (0.045 R)
- M48: 37,313,000 km (0.119 R)
- M49: 37,861,875 km (0.057 R)
- M50: 38,302,889 km (0.115 R)
- M51: 38,856,401 km (0.106 R)
- M52: 42,461,860 km (0.119 R)
- M53: 43,841,302 km (0.109 R)
- M54: 44,420,245 km (0.1 R)
- M55: 44,536,483 km (0.087 R)
- M56: 45,352,090 km (0.106 R)
- M57: 47,828,384 km (0.073 R)
- M58: 48,424,532 km (0.088 R)
- M59: 48,544,060 km (0.027 R)
- M60: 49,503,581 km (0.091 R)
- M61: 50,106,460 km (0.102 R)
- M62: 50,833,207 km (0.097 R)
- M63: 52,052,130 km (0.059 R)
- M64: 55,141,476 km (0.062 R)
- M65: 55,766,346 km (0.094 R)
- M66: 56,645,234 km (0.084 R)
- M67: 59,181,366 km (0.066 R)
- M68: 63,577,150 km (0.089 R)
- M69: 63,969,994 km (0.097 R)
- M70: 64,889,872 km (0.069 R)
- M71: 65,021,667 km (0.057 R)
- M72: 66,078,875 km (0.109 R)
- M73: 67,675,534 km (0.082 R)
- M74: 68,344,535 km (0.057 R)
- M75: 68,612,764 km (0.029 R)
- M76: 68,881,292 km (0.05 R)
- M77: 71,722,306 km (0.041 R)
- M78: 73,088,583 km (0.068 R)
- M79: 73,637,457 km (0.099 R)
- M80: 73,774,938 km (0.103 R)
- M81: 74,601,466 km (0.105 R)
- M82: 77,238,727 km (0.112 R)
- M83: 81,748,804 km (0.091 R)
- M84: 82,318,622 km (0.056 R)
- M85: 84,754,823 km (0.098 R)
- M86: 86,054,081 km (0.111 R)
- M87: 87,359,921 km (0.105 R)
- M88: 89,550,931 km (0.089 R)
- M89: 89,697,686 km (0.097 R)
- M90: 94,285,105 km (0.107 R)
- M91: 95,781,084 km (0.068 R)
- M92: 96,381,719 km (0.053 R)
Kuiper Belt
Range: 30 - 58 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 378 - 12,674 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.