G9V Star System Generated (Seed: 1768741858)
Star Details
Spectral Class: G9V
Temperature: 5,240 K
Mass: 0.91 sol
Luminosity: 0.72 lux
Habitable Zone (HZ)
Inner Boundary: 0.81 AU
Outer Boundary: 1.17 AU
Physical Limits
Snow Line: 4.07 AU
Max System Radius: 19.1 AU
Planetary System (10 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.51 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.89
Radius: 1.89
Gravity: 1.37 G
Time & Orbit
Eccentricity (e): 0.141
Orbit Range: 0.44 AU - 0.58 AU
Year: 139 Days
Day: 38.8 Hours
Environment
Temp: 145 °C
Axial Tilt: 123.3 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 2 - Terrestrial
Semi-Major Axis: 1.23 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.77
Radius: 1.26
Gravity: 1.11 G
Time & Orbit
Eccentricity (e): 0.216
Orbit Range: 0.96 AU - 1.5 AU
Year: 522 Days
Day: 33 Hours
Environment
Temp: -39 °C
Axial Tilt: 37.2 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 3 - Terrestrial
Semi-Major Axis: 1.48 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.16
Radius: 0.48
Gravity: 0.69 G
Time & Orbit
Eccentricity (e): 0.125
Orbit Range: 1.3 AU - 1.67 AU
Year: 689 Days
Day: 36.5 Hours
Environment
Temp: -53 °C
Axial Tilt: 39.4 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 4 - Terrestrial
Semi-Major Axis: 1.58 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 3.41
Radius: 1.63
Gravity: 1.28 G
Time & Orbit
Eccentricity (e): 0.018
Orbit Range: 1.55 AU - 1.61 AU
Year: 760 Days
Day: 28.3 Hours
Environment
Temp: -61 °C
Axial Tilt: 39.9 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 103,675,957 km
- M1: 1,469,051 km (0.078 R)
Planet 5 - Terrestrial
Semi-Major Axis: 3.05 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.88
Radius: 1.89
Gravity: 1.37 G
Time & Orbit
Eccentricity (e): 0.006
Orbit Range: 3.03 AU - 3.07 AU
Year: 2039 Days
Day: 43.8 Hours
Environment
Temp: -110 °C
Axial Tilt: 37.4 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (2)
Outer Limit: 103,675,957 km
- M1: 1,079,049 km (0.12 R)
- M2: 2,021,815 km (0.111 R)
Planet 6 - Gas Giant
Semi-Major Axis: 5.02 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 88.2
Radius: 8.5
Gravity: 1.22 G
Time & Orbit
Eccentricity (e): 0.034
Orbit Range: 4.85 AU - 5.19 AU
Year: 4307 Days
Day: 12.3 Hours
Environment
Temp: -151 °C
Axial Tilt: 24.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (41)
Outer Limit: 103,675,957 km
- M1: 138,827 km (0.025 R)
- M2: 277,654 km (0.119 R)
- M3: 381,475 km (0.097 R)
- M4: 481,705 km (0.114 R)
- M5: 551,867 km (0.093 R)
- M6: 632,949 km (0.099 R)
- M7: 1,285,195 km (0.115 R)
- M8: 1,696,141 km (0.03 R)
- M9: 1,932,057 km (0.075 R)
- M10: 2,059,514 km (0.063 R)
- M11: 2,135,210 km (0.114 R)
- M12: 2,412,864 km (0.048 R)
- M13: 2,504,268 km (0.091 R)
- M14: 2,620,207 km (0.118 R)
- M15: 2,929,725 km (0.061 R)
- M16: 3,480,394 km (0.113 R)
- M17: 3,820,730 km (0.12 R)
- M18: 4,062,629 km (0.063 R)
- M19: 4,199,212 km (0.09 R)
- M20: 4,351,204 km (0.049 R)
- M21: 4,505,140 km (0.095 R)
- M22: 5,375,799 km (0.11 R)
- M23: 5,631,911 km (0.11 R)
- M24: 6,663,538 km (0.111 R)
- M25: 6,808,797 km (0.084 R)
- M26: 6,971,410 km (0.117 R)
- M27: 7,053,091 km (0.072 R)
- M28: 7,118,764 km (0.05 R)
- M29: 7,201,043 km (0.093 R)
- M30: 7,500,239 km (0.051 R)
- M31: 8,613,845 km (0.109 R)
- M32: 8,895,837 km (0.054 R)
- M33: 9,073,709 km (0.039 R)
- M34: 9,288,681 km (0.093 R)
- M35: 9,870,019 km (0.093 R)
- M36: 10,407,075 km (0.091 R)
- M37: 11,010,702 km (0.118 R)
- M38: 11,067,998 km (0.052 R)
- M39: 11,742,236 km (0.104 R)
- M40: 12,588,960 km (0.026 R)
- M41: 13,434,936 km (0.119 R)
Planet 7 - Gas Giant
Semi-Major Axis: 5.56 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 654.8
Radius: 9.5
Gravity: 7.26 G
Time & Orbit
Eccentricity (e): 0.114
Orbit Range: 4.93 AU - 6.19 AU
Year: 5020 Days
Day: 13.8 Hours
Environment
Temp: -161 °C
Axial Tilt: 8.7 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (84)
Outer Limit: 103,675,957 km
- M1: 125,662 km (0.052 R)
- M2: 235,617 km (0.119 R)
- M3: 296,204 km (0.065 R)
- M4: 382,971 km (0.066 R)
- M5: 460,313 km (0.105 R)
- M6: 752,776 km (0.089 R)
- M7: 1,100,143 km (0.045 R)
- M8: 1,478,476 km (0.078 R)
- M9: 1,640,939 km (0.092 R)
- M10: 1,930,860 km (0.098 R)
- M11: 2,037,074 km (0.054 R)
- M12: 2,127,282 km (0.115 R)
- M13: 2,237,087 km (0.095 R)
- M14: 2,462,680 km (0.113 R)
- M15: 2,735,397 km (0.081 R)
- M16: 2,915,812 km (0.082 R)
- M17: 3,416,217 km (0.09 R)
- M18: 3,523,778 km (0.07 R)
- M19: 4,147,601 km (0.036 R)
- M20: 4,542,988 km (0.032 R)
- M21: 5,470,196 km (0.084 R)
- M22: 5,775,076 km (0.119 R)
- M23: 6,007,402 km (0.095 R)
- M24: 6,085,492 km (0.032 R)
- M25: 6,427,921 km (0.069 R)
- M26: 6,967,072 km (0.077 R)
- M27: 7,159,156 km (0.082 R)
- M28: 7,380,860 km (0.075 R)
- M29: 7,576,833 km (0.107 R)
- M30: 7,802,875 km (0.119 R)
- M31: 7,916,719 km (0.111 R)
- M32: 8,174,925 km (0.11 R)
- M33: 8,348,459 km (0.092 R)
- M34: 8,552,660 km (0.075 R)
- M35: 8,906,608 km (0.116 R)
- M36: 9,355,701 km (0.119 R)
- M37: 9,537,463 km (0.1 R)
- M38: 10,432,208 km (0.114 R)
- M39: 10,778,527 km (0.03 R)
- M40: 11,224,927 km (0.1 R)
- M41: 11,353,581 km (0.093 R)
- M42: 11,677,311 km (0.108 R)
- M43: 12,367,106 km (0.041 R)
- M44: 13,137,835 km (0.047 R)
- M45: 13,443,613 km (0.114 R)
- M46: 13,683,119 km (0.062 R)
- M47: 13,923,971 km (0.073 R)
- M48: 14,131,613 km (0.11 R)
- M49: 14,201,027 km (0.103 R)
- M50: 14,270,590 km (0.059 R)
- M51: 14,584,895 km (0.06 R)
- M52: 14,795,828 km (0.099 R)
- M53: 15,901,206 km (0.037 R)
- M54: 16,082,070 km (0.092 R)
- M55: 16,227,180 km (0.096 R)
- M56: 16,665,203 km (0.103 R)
- M57: 17,329,417 km (0.094 R)
- M58: 17,664,816 km (0.102 R)
- M59: 18,115,405 km (0.052 R)
- M60: 18,304,197 km (0.1 R)
- M61: 19,104,546 km (0.116 R)
- M62: 19,258,332 km (0.11 R)
- M63: 20,897,177 km (0.102 R)
- M64: 21,813,614 km (0.1 R)
- M65: 22,095,007 km (0.109 R)
- M66: 22,256,423 km (0.098 R)
- M67: 22,580,452 km (0.096 R)
- M68: 23,232,998 km (0.099 R)
- M69: 23,438,246 km (0.074 R)
- M70: 23,767,960 km (0.095 R)
- M71: 23,974,704 km (0.111 R)
- M72: 24,891,590 km (0.118 R)
- M73: 25,312,259 km (0.066 R)
- M74: 26,032,722 km (0.073 R)
- M75: 26,117,843 km (0.11 R)
- M76: 26,630,964 km (0.11 R)
- M77: 26,802,852 km (0.091 R)
- M78: 27,104,292 km (0.119 R)
- M79: 27,277,077 km (0.1 R)
- M80: 27,536,929 km (0.07 R)
- M81: 27,797,678 km (0.073 R)
- M82: 28,146,690 km (0.076 R)
- M83: 28,760,639 km (0.077 R)
- M84: 29,113,541 km (0.088 R)
Planet 8 - Gas Giant
Semi-Major Axis: 6.11 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 453.7
Radius: 12.9
Gravity: 2.73 G
Time & Orbit
Eccentricity (e): 0.244
Orbit Range: 4.62 AU - 7.6 AU
Year: 5783 Days
Day: 12.3 Hours
Environment
Temp: -168 °C
Axial Tilt: 8.9 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (73)
Outer Limit: 103,675,957 km
- M1: 167,699 km (0.115 R)
- M2: 248,183 km (0.077 R)
- M3: 399,875 km (0.069 R)
- M4: 492,626 km (0.084 R)
- M5: 850,015 km (0.09 R)
- M6: 1,086,230 km (0.07 R)
- M7: 1,419,684 km (0.108 R)
- M8: 1,835,865 km (0.107 R)
- M9: 1,920,388 km (0.115 R)
- M10: 2,164,083 km (0.073 R)
- M11: 2,326,247 km (0.115 R)
- M12: 2,436,800 km (0.063 R)
- M13: 2,548,998 km (0.094 R)
- M14: 2,759,333 km (0.103 R)
- M15: 3,035,640 km (0.043 R)
- M16: 3,116,124 km (0.107 R)
- M17: 3,218,000 km (0.107 R)
- M18: 4,274,310 km (0.116 R)
- M19: 4,923,116 km (0.103 R)
- M20: 5,381,185 km (0.07 R)
- M21: 5,878,149 km (0.107 R)
- M22: 6,106,735 km (0.116 R)
- M23: 6,260,671 km (0.081 R)
- M24: 6,364,043 km (0.104 R)
- M25: 6,625,091 km (0.066 R)
- M26: 6,809,845 km (0.089 R)
- M27: 6,916,209 km (0.105 R)
- M28: 7,538,835 km (0.04 R)
- M29: 7,870,793 km (0.095 R)
- M30: 8,066,766 km (0.091 R)
- M31: 8,235,961 km (0.105 R)
- M32: 8,463,350 km (0.105 R)
- M33: 8,866,516 km (0.085 R)
- M34: 9,041,247 km (0.102 R)
- M35: 9,512,779 km (0.102 R)
- M36: 9,931,952 km (0.07 R)
- M37: 10,204,520 km (0.09 R)
- M38: 10,695,500 km (0.097 R)
- M39: 10,819,367 km (0.092 R)
- M40: 11,509,611 km (0.089 R)
- M41: 11,892,133 km (0.105 R)
- M42: 13,530,828 km (0.069 R)
- M43: 14,070,129 km (0.116 R)
- M44: 14,479,279 km (0.032 R)
- M45: 15,344,104 km (0.067 R)
- M46: 15,800,378 km (0.107 R)
- M47: 17,051,315 km (0.1 R)
- M48: 17,159,923 km (0.11 R)
- M49: 17,597,048 km (0.111 R)
- M50: 17,927,360 km (0.119 R)
- M51: 18,668,617 km (0.042 R)
- M52: 18,780,666 km (0.041 R)
- M53: 19,193,407 km (0.116 R)
- M54: 19,571,291 km (0.076 R)
- M55: 19,685,285 km (0.111 R)
- M56: 20,028,013 km (0.081 R)
- M57: 21,614,948 km (0.118 R)
- M58: 21,811,220 km (0.041 R)
- M59: 22,841,500 km (0.109 R)
- M60: 23,001,421 km (0.113 R)
- M61: 23,483,425 km (0.11 R)
- M62: 23,564,058 km (0.098 R)
- M63: 23,887,638 km (0.074 R)
- M64: 24,702,947 km (0.113 R)
- M65: 25,072,902 km (0.057 R)
- M66: 25,320,487 km (0.046 R)
- M67: 26,781,011 km (0.062 R)
- M68: 26,991,944 km (0.11 R)
- M69: 27,203,326 km (0.096 R)
- M70: 28,526,519 km (0.109 R)
- M71: 28,612,538 km (0.074 R)
- M72: 28,698,706 km (0.108 R)
- M73: 28,828,108 km (0.085 R)
Planet 9 - Gas Giant
Semi-Major Axis: 9.05 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 207.2
Radius: 9.1
Gravity: 2.5 G
Time & Orbit
Eccentricity (e): 0.114
Orbit Range: 8.02 AU - 10.08 AU
Year: 10424 Days
Day: 8.5 Hours
Environment
Temp: -182 °C
Axial Tilt: 10.5 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (83)
Outer Limit: 103,675,957 km
- M1: 206,445 km (0.11 R)
- M2: 470,784 km (0.111 R)
- M3: 585,676 km (0.108 R)
- M4: 672,143 km (0.095 R)
- M5: 1,033,123 km (0.078 R)
- M6: 1,552,676 km (0.093 R)
- M7: 1,640,640 km (0.085 R)
- M8: 1,730,249 km (0.106 R)
- M9: 2,066,844 km (0.069 R)
- M10: 2,526,558 km (0.099 R)
- M11: 2,736,295 km (0.094 R)
- M12: 3,039,679 km (0.114 R)
- M13: 3,218,000 km (0.104 R)
- M14: 3,399,612 km (0.118 R)
- M15: 3,725,885 km (0.061 R)
- M16: 3,820,879 km (0.086 R)
- M17: 3,916,771 km (0.117 R)
- M18: 4,013,412 km (0.04 R)
- M19: 4,110,949 km (0.06 R)
- M20: 4,233,919 km (0.087 R)
- M21: 4,358,235 km (0.088 R)
- M22: 5,128,963 km (0.073 R)
- M23: 5,368,469 km (0.078 R)
- M24: 5,584,339 km (0.096 R)
- M25: 5,830,727 km (0.05 R)
- M26: 6,305,999 km (0.109 R)
- M27: 6,910,075 km (0.07 R)
- M28: 7,086,152 km (0.099 R)
- M29: 7,592,990 km (0.093 R)
- M30: 7,774,601 km (0.078 R)
- M31: 8,204,097 km (0.111 R)
- M32: 8,453,177 km (0.098 R)
- M33: 8,515,709 km (0.046 R)
- M34: 8,641,521 km (0.116 R)
- M35: 8,799,496 km (0.11 R)
- M36: 9,702,020 km (0.1 R)
- M37: 10,264,508 km (0.109 R)
- M38: 10,499,078 km (0.094 R)
- M39: 10,939,494 km (0.103 R)
- M40: 11,420,750 km (0.12 R)
- M41: 11,490,014 km (0.11 R)
- M42: 12,226,036 km (0.103 R)
- M43: 12,581,929 km (0.068 R)
- M44: 13,158,479 km (0.11 R)
- M45: 13,559,850 km (0.042 R)
- M46: 14,262,661 km (0.087 R)
- M47: 14,412,109 km (0.072 R)
- M48: 14,977,290 km (0.094 R)
- M49: 15,205,427 km (0.092 R)
- M50: 15,281,722 km (0.047 R)
- M51: 16,051,552 km (0.112 R)
- M52: 17,110,855 km (0.079 R)
- M53: 17,269,728 km (0.097 R)
- M54: 17,468,992 km (0.098 R)
- M55: 17,669,005 km (0.102 R)
- M56: 18,233,138 km (0.088 R)
- M57: 18,885,086 km (0.088 R)
- M58: 19,710,716 km (0.117 R)
- M59: 20,421,755 km (0.089 R)
- M60: 20,971,228 km (0.07 R)
- M61: 21,311,862 km (0.057 R)
- M62: 21,654,142 km (0.085 R)
- M63: 22,214,386 km (0.091 R)
- M64: 23,129,476 km (0.055 R)
- M65: 23,790,549 km (0.083 R)
- M66: 24,502,635 km (0.118 R)
- M67: 26,359,145 km (0.113 R)
- M68: 26,726,707 km (0.06 R)
- M69: 27,049,689 km (0.107 R)
- M70: 27,234,741 km (0.079 R)
- M71: 27,652,867 km (0.059 R)
- M72: 28,448,279 km (0.09 R)
- M73: 28,589,499 km (0.106 R)
- M74: 28,730,869 km (0.077 R)
- M75: 28,919,812 km (0.118 R)
- M76: 29,298,893 km (0.092 R)
- M77: 29,822,635 km (0.057 R)
- M78: 29,966,099 km (0.118 R)
- M79: 30,061,842 km (0.047 R)
- M80: 30,590,221 km (0.041 R)
- M81: 31,121,593 km (0.107 R)
- M82: 31,851,182 km (0.103 R)
- M83: 32,438,952 km (0.035 R)
Planet 10 - Ice Giant
Semi-Major Axis: 18.08 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 800
Radius: 7.9
Gravity: 12.82 G
Time & Orbit
Eccentricity (e): 0.23
Orbit Range: 13.92 AU - 22.24 AU
Year: 29435 Days
Day: 23.6 Hours
Environment
Temp: -194 °C
Axial Tilt: 39.9 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (93)
Outer Limit: 103,675,957 km
- M1: 217,814 km (0.08 R)
- M2: 307,872 km (0.107 R)
- M3: 483,351 km (0.055 R)
- M4: 1,120,189 km (0.036 R)
- M5: 1,256,323 km (0.103 R)
- M6: 1,697,337 km (0.086 R)
- M7: 1,975,589 km (0.045 R)
- M8: 3,324,663 km (0.089 R)
- M9: 4,137,578 km (0.03 R)
- M10: 4,243,493 km (0.045 R)
- M11: 5,065,683 km (0.114 R)
- M12: 5,350,517 km (0.105 R)
- M13: 5,876,504 km (0.084 R)
- M14: 6,418,945 km (0.106 R)
- M15: 7,166,935 km (0.073 R)
- M16: 8,340,081 km (0.111 R)
- M17: 9,362,583 km (0.102 R)
- M18: 9,853,114 km (0.105 R)
- M19: 10,640,897 km (0.099 R)
- M20: 10,713,601 km (0.114 R)
- M21: 12,505,484 km (0.05 R)
- M22: 13,514,372 km (0.074 R)
- M23: 14,308,139 km (0.067 R)
- M24: 15,691,769 km (0.103 R)
- M25: 15,857,374 km (0.111 R)
- M26: 15,940,401 km (0.098 R)
- M27: 16,525,628 km (0.077 R)
- M28: 17,975,830 km (0.091 R)
- M29: 19,555,284 km (0.098 R)
- M30: 20,451,824 km (0.101 R)
- M31: 20,905,106 km (0.116 R)
- M32: 22,377,897 km (0.083 R)
- M33: 24,552,900 km (0.077 R)
- M34: 24,648,942 km (0.066 R)
- M35: 25,034,605 km (0.091 R)
- M36: 25,909,454 km (0.108 R)
- M37: 26,992,393 km (0.098 R)
- M38: 30,225,801 km (0.085 R)
- M39: 30,845,435 km (0.07 R)
- M40: 31,469,408 km (0.058 R)
- M41: 33,047,516 km (0.11 R)
- M42: 33,685,850 km (0.098 R)
- M43: 34,543,345 km (0.047 R)
- M44: 35,408,170 km (0.117 R)
- M45: 35,952,108 km (0.054 R)
- M46: 37,158,765 km (0.098 R)
- M47: 40,176,453 km (0.052 R)
- M48: 40,971,566 km (0.101 R)
- M49: 41,085,559 km (0.068 R)
- M50: 43,271,782 km (0.031 R)
- M51: 43,853,419 km (0.076 R)
- M52: 46,205,546 km (0.041 R)
- M53: 46,680,819 km (0.044 R)
- M54: 49,202,740 km (0.05 R)
- M55: 49,445,238 km (0.106 R)
- M56: 51,399,435 km (0.066 R)
- M57: 52,138,747 km (0.099 R)
- M58: 53,005,817 km (0.118 R)
- M59: 54,127,502 km (0.034 R)
- M60: 55,509,038 km (0.111 R)
- M61: 56,775,085 km (0.105 R)
- M62: 58,306,817 km (0.119 R)
- M63: 63,246,240 km (0.065 R)
- M64: 63,378,036 km (0.032 R)
- M65: 64,038,361 km (0.086 R)
- M66: 65,632,326 km (0.052 R)
- M67: 67,778,008 km (0.093 R)
- M68: 68,859,451 km (0.116 R)
- M69: 69,130,672 km (0.085 R)
- M70: 70,219,146 km (0.044 R)
- M71: 70,355,729 km (0.112 R)
- M72: 72,275,518 km (0.114 R)
- M73: 73,657,204 km (0.059 R)
- M74: 75,886,213 km (0.104 R)
- M75: 76,166,409 km (0.076 R)
- M76: 84,584,880 km (0.071 R)
- M77: 86,040,617 km (0.048 R)
- M78: 86,625,245 km (0.099 R)
- M79: 88,534,413 km (0.096 R)
- M80: 90,605,895 km (0.081 R)
- M81: 91,946,142 km (0.107 R)
- M82: 92,244,740 km (0.093 R)
- M83: 92,394,188 km (0.04 R)
- M84: 92,543,786 km (0.088 R)
- M85: 93,292,673 km (0.071 R)
- M86: 94,344,645 km (0.054 R)
- M87: 94,947,525 km (0.065 R)
- M88: 96,157,023 km (0.086 R)
- M89: 96,611,950 km (0.079 R)
- M90: 98,438,690 km (0.117 R)
- M91: 99,050,097 km (0.118 R)
- M92: 99,662,849 km (0.12 R)
- M93: 99,816,187 km (0.116 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: 553 - 19,228 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.