G4V Star System Generated (Seed: 1766178782)
Star Details
Spectral Class: G0V
Temperature: 6,000 K
Mass: 1.1 sol
Luminosity: 1.4 lux
Habitable Zone (HZ)
Inner Boundary: 1.13 AU
Outer Boundary: 1.63 AU
Physical Limits
Snow Line: 5.68 AU
Max System Radius: 21 AU
Planetary System (7 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.65 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.33
Radius: 0.64
Gravity: 0.81 G
Time & Orbit
Eccentricity (e): 0.136
Orbit Range: 0.56 AU - 0.74 AU
Year: 183 Days
Day: 17 Hours
Environment
Temp: 227 °C
Axial Tilt: 32.8 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (1)
Outer Limit: 75,937,644 km
- M1: 257,159 km (0.044 R)
Planet 2 - Terrestrial
Semi-Major Axis: 1.41 AU
Status: HZ
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.76
Radius: 0.9
Gravity: 0.94 G
Time & Orbit
Eccentricity (e): 0.183
Orbit Range: 1.15 AU - 1.67 AU
Year: 583 Days
Day: 15.1 Hours
Environment
Temp: 12 °C
Axial Tilt: 39.7 °
Atmosphere: Nâ‚‚, Oâ‚‚
Biome: Arid/Tundra
Planet 3 - Gas Giant
Semi-Major Axis: 6.57 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 33.4
Radius: 14
Gravity: 0.17 G
Time & Orbit
Eccentricity (e): 0.131
Orbit Range: 5.71 AU - 7.43 AU
Year: 5865 Days
Day: 8.8 Hours
Environment
Temp: -150 °C
Axial Tilt: 14.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (50)
Outer Limit: 75,937,644 km
- M1: 174,431 km (0.101 R)
- M2: 351,854 km (0.101 R)
- M3: 458,069 km (0.107 R)
- M4: 556,654 km (0.032 R)
- M5: 835,055 km (0.118 R)
- M6: 948,151 km (0.116 R)
- M7: 1,044,492 km (0.069 R)
- M8: 1,231,639 km (0.073 R)
- M9: 1,329,775 km (0.115 R)
- M10: 1,534,425 km (0.072 R)
- M11: 1,796,072 km (0.068 R)
- M12: 2,131,770 km (0.117 R)
- M13: 2,241,574 km (0.11 R)
- M14: 2,593,129 km (0.102 R)
- M15: 2,819,321 km (0.069 R)
- M16: 2,951,566 km (0.1 R)
- M17: 3,041,026 km (0.036 R)
- M18: 3,131,233 km (0.037 R)
- M19: 3,245,376 km (0.104 R)
- M20: 3,337,828 km (0.089 R)
- M21: 3,910,788 km (0.102 R)
- M22: 4,133,688 km (0.093 R)
- M23: 4,272,066 km (0.102 R)
- M24: 4,399,075 km (0.111 R)
- M25: 4,801,344 km (0.115 R)
- M26: 4,920,424 km (0.073 R)
- M27: 5,365,328 km (0.116 R)
- M28: 5,461,519 km (0.105 R)
- M29: 5,572,072 km (0.11 R)
- M30: 5,711,198 km (0.084 R)
- M31: 6,294,330 km (0.112 R)
- M32: 6,527,105 km (0.113 R)
- M33: 6,659,349 km (0.118 R)
- M34: 6,807,302 km (0.089 R)
- M35: 7,151,676 km (0.12 R)
- M36: 7,548,110 km (0.118 R)
- M37: 8,045,822 km (0.113 R)
- M38: 8,219,356 km (0.109 R)
- M39: 8,314,500 km (0.113 R)
- M40: 8,634,639 km (0.104 R)
- M41: 8,779,899 km (0.093 R)
- M42: 8,909,900 km (0.052 R)
- M43: 9,452,491 km (0.081 R)
- M44: 9,955,140 km (0.092 R)
- M45: 10,415,004 km (0.094 R)
- M46: 11,004,120 km (0.099 R)
- M47: 11,338,023 km (0.073 R)
- M48: 11,693,168 km (0.107 R)
- M49: 11,961,995 km (0.049 R)
- M50: 12,178,463 km (0.1 R)
Planet 4 - Gas Giant
Semi-Major Axis: 7.32 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 901.9
Radius: 13.7
Gravity: 4.81 G
Time & Orbit
Eccentricity (e): 0.093
Orbit Range: 6.64 AU - 8 AU
Year: 6897 Days
Day: 13.9 Hours
Environment
Temp: -151 °C
Axial Tilt: 48.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (82)
Outer Limit: 75,937,644 km
- M1: 173,982 km (0.095 R)
- M2: 260,899 km (0.078 R)
- M3: 404,213 km (0.103 R)
- M4: 599,887 km (0.106 R)
- M5: 697,126 km (0.062 R)
- M6: 1,042,996 km (0.034 R)
- M7: 1,146,967 km (0.077 R)
- M8: 1,254,677 km (0.116 R)
- M9: 1,385,127 km (0.101 R)
- M10: 1,619,846 km (0.082 R)
- M11: 2,332,680 km (0.117 R)
- M12: 2,686,778 km (0.113 R)
- M13: 3,058,229 km (0.082 R)
- M14: 3,160,255 km (0.1 R)
- M15: 3,988,878 km (0.055 R)
- M16: 4,100,627 km (0.086 R)
- M17: 4,645,911 km (0.115 R)
- M18: 4,763,645 km (0.108 R)
- M19: 6,221,327 km (0.036 R)
- M20: 6,614,470 km (0.116 R)
- M21: 7,185,335 km (0.044 R)
- M22: 7,322,068 km (0.089 R)
- M23: 8,018,296 km (0.095 R)
- M24: 8,160,115 km (0.075 R)
- M25: 8,338,585 km (0.064 R)
- M26: 8,518,402 km (0.083 R)
- M27: 9,028,680 km (0.112 R)
- M28: 9,139,233 km (0.067 R)
- M29: 10,347,685 km (0.104 R)
- M30: 11,128,286 km (0.101 R)
- M31: 11,247,067 km (0.108 R)
- M32: 11,605,803 km (0.04 R)
- M33: 12,049,510 km (0.117 R)
- M34: 12,995,268 km (0.028 R)
- M35: 13,120,332 km (0.051 R)
- M36: 13,371,806 km (0.106 R)
- M37: 13,624,776 km (0.079 R)
- M38: 14,739,729 km (0.103 R)
- M39: 14,957,543 km (0.099 R)
- M40: 15,044,908 km (0.106 R)
- M41: 15,352,182 km (0.031 R)
- M42: 15,440,445 km (0.081 R)
- M43: 16,466,686 km (0.113 R)
- M44: 16,919,669 km (0.094 R)
- M45: 17,285,136 km (0.065 R)
- M46: 17,468,843 km (0.093 R)
- M47: 17,838,200 km (0.083 R)
- M48: 18,584,693 km (0.102 R)
- M49: 18,725,764 km (0.088 R)
- M50: 19,341,359 km (0.052 R)
- M51: 20,059,878 km (0.047 R)
- M52: 21,129,652 km (0.029 R)
- M53: 21,770,380 km (0.075 R)
- M54: 22,168,011 km (0.12 R)
- M55: 22,367,724 km (0.054 R)
- M56: 22,567,886 km (0.1 R)
- M57: 22,869,475 km (0.055 R)
- M58: 23,121,697 km (0.099 R)
- M59: 24,088,997 km (0.12 R)
- M60: 24,242,933 km (0.078 R)
- M61: 24,448,630 km (0.118 R)
- M62: 25,225,343 km (0.109 R)
- M63: 25,329,612 km (0.097 R)
- M64: 25,590,661 km (0.084 R)
- M65: 26,696,937 km (0.061 R)
- M66: 26,856,259 km (0.097 R)
- M67: 27,550,243 km (0.084 R)
- M68: 28,196,207 km (0.115 R)
- M69: 28,956,014 km (0.116 R)
- M70: 29,393,289 km (0.105 R)
- M71: 29,557,846 km (0.08 R)
- M72: 30,385,123 km (0.046 R)
- M73: 30,718,128 km (0.097 R)
- M74: 31,893,368 km (0.065 R)
- M75: 33,083,270 km (0.057 R)
- M76: 34,057,152 km (0.106 R)
- M77: 34,229,938 km (0.08 R)
- M78: 35,740,128 km (0.069 R)
- M79: 36,091,683 km (0.105 R)
- M80: 37,807,271 km (0.071 R)
- M81: 38,945,562 km (0.088 R)
- M82: 39,428,314 km (0.111 R)
Planet 5 - Ice Giant
Semi-Major Axis: 13.36 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 769.5
Radius: 4.9
Gravity: 32.05 G
Time & Orbit
Eccentricity (e): 0.029
Orbit Range: 12.97 AU - 13.75 AU
Year: 17006 Days
Day: 16.4 Hours
Environment
Temp: -173 °C
Axial Tilt: 26.8 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (95)
Outer Limit: 75,937,644 km
- M1: 111,750 km (0.114 R)
- M2: 142,716 km (0.084 R)
- M3: 358,287 km (0.036 R)
- M4: 545,434 km (0.06 R)
- M5: 715,527 km (0.115 R)
- M6: 760,705 km (0.055 R)
- M7: 853,905 km (0.079 R)
- M8: 1,000,959 km (0.119 R)
- M9: 1,635,853 km (0.107 R)
- M10: 1,696,141 km (0.036 R)
- M11: 1,912,609 km (0.093 R)
- M12: 2,439,941 km (0.112 R)
- M13: 4,222,998 km (0.103 R)
- M14: 4,305,876 km (0.052 R)
- M15: 4,728,789 km (0.098 R)
- M16: 6,215,792 km (0.076 R)
- M17: 7,280,629 km (0.066 R)
- M18: 7,480,342 km (0.101 R)
- M19: 8,348,608 km (0.092 R)
- M20: 9,140,879 km (0.12 R)
- M21: 11,081,013 km (0.112 R)
- M22: 11,425,986 km (0.111 R)
- M23: 12,660,767 km (0.038 R)
- M24: 12,961,010 km (0.116 R)
- M25: 13,629,712 km (0.059 R)
- M26: 14,372,017 km (0.082 R)
- M27: 14,811,087 km (0.062 R)
- M28: 15,063,907 km (0.073 R)
- M29: 15,895,522 km (0.12 R)
- M30: 16,284,327 km (0.076 R)
- M31: 16,414,626 km (0.096 R)
- M32: 16,676,273 km (0.045 R)
- M33: 16,741,947 km (0.045 R)
- M34: 21,544,188 km (0.06 R)
- M35: 22,624,883 km (0.049 R)
- M36: 22,916,000 km (0.075 R)
- M37: 24,167,087 km (0.096 R)
- M38: 24,614,086 km (0.12 R)
- M39: 24,838,482 km (0.075 R)
- M40: 25,138,875 km (0.104 R)
- M41: 25,289,370 km (0.066 R)
- M42: 25,743,101 km (0.079 R)
- M43: 27,739,784 km (0.059 R)
- M44: 28,520,834 km (0.071 R)
- M45: 29,071,953 km (0.1 R)
- M46: 30,264,696 km (0.094 R)
- M47: 30,424,916 km (0.081 R)
- M48: 31,473,298 km (0.046 R)
- M49: 31,554,380 km (0.087 R)
- M50: 32,287,708 km (0.101 R)
- M51: 33,191,579 km (0.099 R)
- M52: 34,270,628 km (0.11 R)
- M53: 34,940,228 km (0.068 R)
- M54: 35,698,689 km (0.099 R)
- M55: 38,439,472 km (0.082 R)
- M56: 39,309,683 km (0.098 R)
- M57: 40,980,990 km (0.105 R)
- M58: 41,335,687 km (0.117 R)
- M59: 41,513,559 km (0.084 R)
- M60: 43,124,877 km (0.084 R)
- M61: 43,666,571 km (0.056 R)
- M62: 48,454,601 km (0.062 R)
- M63: 48,548,249 km (0.116 R)
- M64: 48,923,590 km (0.117 R)
- M65: 49,394,225 km (0.1 R)
- M66: 49,960,902 km (0.089 R)
- M67: 50,339,833 km (0.119 R)
- M68: 50,814,956 km (0.109 R)
- M69: 51,005,394 km (0.097 R)
- M70: 54,181,806 km (0.118 R)
- M71: 54,766,284 km (0.049 R)
- M72: 55,059,197 km (0.076 R)
- M73: 56,039,512 km (0.053 R)
- M74: 56,531,988 km (0.096 R)
- M75: 56,630,573 km (0.097 R)
- M76: 57,223,579 km (0.119 R)
- M77: 57,719,346 km (0.117 R)
- M78: 57,818,679 km (0.114 R)
- M79: 58,715,219 km (0.118 R)
- M80: 59,817,157 km (0.093 R)
- M81: 61,128,233 km (0.037 R)
- M82: 61,939,652 km (0.069 R)
- M83: 62,244,981 km (0.107 R)
- M84: 63,061,337 km (0.088 R)
- M85: 63,265,987 km (0.073 R)
- M86: 65,014,487 km (0.119 R)
- M87: 65,324,753 km (0.081 R)
- M88: 66,987,383 km (0.096 R)
- M89: 67,300,791 km (0.083 R)
- M90: 68,980,027 km (0.11 R)
- M91: 69,401,893 km (0.052 R)
- M92: 69,718,891 km (0.085 R)
- M93: 70,036,487 km (0.071 R)
- M94: 70,248,318 km (0.116 R)
- M95: 70,354,383 km (0.065 R)
Planet 6 - Ice Giant
Semi-Major Axis: 15.17 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 862.2
Radius: 3
Gravity: 95.8 G
Time & Orbit
Eccentricity (e): 0.001
Orbit Range: 15.15 AU - 15.19 AU
Year: 20577 Days
Day: 23.8 Hours
Environment
Temp: -189 °C
Axial Tilt: 38.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (93)
Outer Limit: 75,937,644 km
- M1: 39,943 km (0.112 R)
- M2: 86,318 km (0.07 R)
- M3: 147,354 km (0.095 R)
- M4: 329,265 km (0.07 R)
- M5: 408,552 km (0.109 R)
- M6: 809,773 km (0.077 R)
- M7: 1,176,138 km (0.117 R)
- M8: 1,360,593 km (0.041 R)
- M9: 1,654,104 km (0.117 R)
- M10: 1,860,399 km (0.101 R)
- M11: 2,565,603 km (0.113 R)
- M12: 2,844,155 km (0.09 R)
- M13: 3,007,516 km (0.1 R)
- M14: 3,472,765 km (0.075 R)
- M15: 3,824,918 km (0.066 R)
- M16: 4,050,811 km (0.087 R)
- M17: 4,705,900 km (0.105 R)
- M18: 6,481,627 km (0.11 R)
- M19: 6,968,269 km (0.116 R)
- M20: 7,522,529 km (0.088 R)
- M21: 9,876,900 km (0.066 R)
- M22: 9,938,535 km (0.059 R)
- M23: 10,877,112 km (0.099 R)
- M24: 12,303,976 km (0.098 R)
- M25: 12,503,091 km (0.095 R)
- M26: 12,837,292 km (0.099 R)
- M27: 13,926,365 km (0.053 R)
- M28: 14,203,121 km (0.087 R)
- M29: 14,342,247 km (0.028 R)
- M30: 14,551,834 km (0.091 R)
- M31: 15,257,487 km (0.108 R)
- M32: 16,995,814 km (0.105 R)
- M33: 18,038,511 km (0.093 R)
- M34: 19,795,837 km (0.116 R)
- M35: 20,263,181 km (0.083 R)
- M36: 20,498,199 km (0.116 R)
- M37: 21,686,904 km (0.109 R)
- M38: 22,653,755 km (0.072 R)
- M39: 23,717,097 km (0.094 R)
- M40: 25,047,770 km (0.084 R)
- M41: 27,088,883 km (0.078 R)
- M42: 27,780,923 km (0.119 R)
- M43: 28,654,275 km (0.082 R)
- M44: 29,094,392 km (0.059 R)
- M45: 29,714,176 km (0.067 R)
- M46: 31,871,976 km (0.076 R)
- M47: 33,061,578 km (0.11 R)
- M48: 34,545,739 km (0.098 R)
- M49: 34,732,736 km (0.118 R)
- M50: 35,390,069 km (0.11 R)
- M51: 36,716,853 km (0.027 R)
- M52: 39,418,889 km (0.119 R)
- M53: 41,685,895 km (0.12 R)
- M54: 42,484,299 km (0.114 R)
- M55: 43,388,469 km (0.064 R)
- M56: 43,489,298 km (0.103 R)
- M57: 44,400,498 km (0.118 R)
- M58: 44,705,678 km (0.114 R)
- M59: 45,011,456 km (0.082 R)
- M60: 45,113,482 km (0.076 R)
- M61: 45,933,129 km (0.063 R)
- M62: 46,757,562 km (0.088 R)
- M63: 48,316,522 km (0.065 R)
- M64: 51,698,930 km (0.083 R)
- M65: 53,418,408 km (0.102 R)
- M66: 53,634,726 km (0.116 R)
- M67: 56,913,463 km (0.105 R)
- M68: 58,576,991 km (0.092 R)
- M69: 60,031,531 km (0.084 R)
- M70: 60,256,377 km (0.112 R)
- M71: 60,368,874 km (0.111 R)
- M72: 61,497,889 km (0.059 R)
- M73: 63,204,652 km (0.084 R)
- M74: 64,811,482 km (0.048 R)
- M75: 66,431,777 km (0.075 R)
- M76: 66,664,252 km (0.089 R)
- M77: 69,358,061 km (0.1 R)
- M78: 69,475,944 km (0.033 R)
- M79: 70,421,851 km (0.103 R)
- M80: 70,896,376 km (0.081 R)
- M81: 73,645,237 km (0.107 R)
- M82: 74,006,366 km (0.096 R)
- M83: 74,126,792 km (0.1 R)
- M84: 75,214,369 km (0.096 R)
- M85: 76,185,408 km (0.05 R)
- M86: 76,672,499 km (0.107 R)
- M87: 77,527,301 km (0.087 R)
- M88: 77,772,193 km (0.063 R)
- M89: 78,631,184 km (0.091 R)
- M90: 80,482,308 km (0.086 R)
- M91: 80,730,192 km (0.061 R)
- M92: 81,724,419 km (0.047 R)
- M93: 82,472,558 km (0.073 R)
Planet 7 - Ice Giant
Semi-Major Axis: 19.2 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 317.3
Radius: 6.9
Gravity: 6.66 G
Time & Orbit
Eccentricity (e): 0.005
Orbit Range: 19.1 AU - 19.3 AU
Year: 29299 Days
Day: 16.9 Hours
Environment
Temp: -203 °C
Axial Tilt: 9.6 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (94)
Outer Limit: 75,937,644 km
- M1: 88,263 km (0.095 R)
- M2: 225,145 km (0.07 R)
- M3: 284,535 km (0.091 R)
- M4: 441,164 km (0.032 R)
- M5: 561,291 km (0.102 R)
- M6: 625,618 km (0.089 R)
- M7: 692,638 km (0.104 R)
- M8: 1,228,647 km (0.109 R)
- M9: 1,551,180 km (0.08 R)
- M10: 1,643,781 km (0.101 R)
- M11: 2,237,087 km (0.048 R)
- M12: 2,629,781 km (0.059 R)
- M13: 2,740,633 km (0.104 R)
- M14: 2,967,124 km (0.029 R)
- M15: 3,318,081 km (0.084 R)
- M16: 3,600,222 km (0.11 R)
- M17: 3,848,256 km (0.073 R)
- M18: 4,016,703 km (0.114 R)
- M19: 4,625,267 km (0.068 R)
- M20: 4,804,485 km (0.089 R)
- M21: 5,169,654 km (0.061 R)
- M22: 6,667,727 km (0.118 R)
- M23: 7,126,244 km (0.12 R)
- M24: 7,700,401 km (0.107 R)
- M25: 7,966,386 km (0.12 R)
- M26: 8,019,942 km (0.112 R)
- M27: 8,127,353 km (0.082 R)
- M28: 8,726,941 km (0.046 R)
- M29: 10,316,419 km (0.119 R)
- M30: 10,609,481 km (0.031 R)
- M31: 10,964,926 km (0.108 R)
- M32: 11,203,983 km (0.063 R)
- M33: 11,626,597 km (0.09 R)
- M34: 11,870,292 km (0.041 R)
- M35: 12,177,566 km (0.107 R)
- M36: 12,363,067 km (0.108 R)
- M37: 13,241,356 km (0.114 R)
- M38: 13,368,365 km (0.12 R)
- M39: 14,139,542 km (0.114 R)
- M40: 14,925,080 km (0.094 R)
- M41: 14,991,053 km (0.097 R)
- M42: 15,123,597 km (0.047 R)
- M43: 16,469,828 km (0.047 R)
- M44: 16,743,592 km (0.063 R)
- M45: 16,812,258 km (0.097 R)
- M46: 17,226,494 km (0.085 R)
- M47: 17,783,896 km (0.116 R)
- M48: 18,631,068 km (0.118 R)
- M49: 19,347,044 km (0.06 R)
- M50: 21,473,727 km (0.058 R)
- M51: 22,450,900 km (0.09 R)
- M52: 22,754,584 km (0.108 R)
- M53: 24,604,511 km (0.047 R)
- M54: 24,917,470 km (0.108 R)
- M55: 25,074,548 km (0.107 R)
- M56: 25,705,851 km (0.071 R)
- M57: 25,864,425 km (0.102 R)
- M58: 28,775,001 km (0.07 R)
- M59: 28,939,708 km (0.095 R)
- M60: 30,101,635 km (0.079 R)
- M61: 31,447,866 km (0.067 R)
- M62: 33,072,200 km (0.1 R)
- M63: 34,286,336 km (0.106 R)
- M64: 36,668,832 km (0.057 R)
- M65: 37,205,439 km (0.044 R)
- M66: 37,564,624 km (0.055 R)
- M67: 38,015,362 km (0.088 R)
- M68: 38,377,090 km (0.12 R)
- M69: 38,467,746 km (0.118 R)
- M70: 39,195,390 km (0.077 R)
- M71: 39,652,412 km (0.076 R)
- M72: 40,295,234 km (0.11 R)
- M73: 41,684,399 km (0.107 R)
- M74: 42,057,497 km (0.066 R)
- M75: 44,986,174 km (0.076 R)
- M76: 45,560,630 km (0.1 R)
- M77: 47,492,836 km (0.087 R)
- M78: 48,763,072 km (0.039 R)
- M79: 50,143,411 km (0.115 R)
- M80: 50,440,812 km (0.027 R)
- M81: 50,838,443 km (0.079 R)
- M82: 50,937,925 km (0.118 R)
- M83: 54,157,571 km (0.082 R)
- M84: 54,564,627 km (0.093 R)
- M85: 60,685,573 km (0.096 R)
- M86: 61,532,147 km (0.082 R)
- M87: 63,343,927 km (0.07 R)
- M88: 65,497,987 km (0.03 R)
- M89: 65,931,671 km (0.096 R)
- M90: 68,114,304 km (0.093 R)
- M91: 71,655,435 km (0.088 R)
- M92: 72,326,083 km (0.078 R)
- M93: 72,886,476 km (0.109 R)
- M94: 73,223,371 km (0.096 R)
Kuiper Belt
Range: 31.5 - 47.5 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 234 - 15,251 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.