G8V Star System Generated (Seed: 1767140298)
Star Details
Spectral Class: G8V
Temperature: 5,280 K
Mass: 0.92 sol
Luminosity: 0.75 lux
Habitable Zone (HZ)
Inner Boundary: 0.83 AU
Outer Boundary: 1.19 AU
Physical Limits
Snow Line: 4.16 AU
Max System Radius: 19.2 AU
Planetary System (9 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.64 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.38
Radius: 1.81
Gravity: 1.34 G
Time & Orbit
Eccentricity (e): 0.228
Orbit Range: 0.49 AU - 0.79 AU
Year: 195 Days
Day: 36.4 Hours
Environment
Temp: 171 °C
Axial Tilt: 29 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 2 - Terrestrial
Semi-Major Axis: 0.73 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.14
Radius: 1.05
Gravity: 1.03 G
Time & Orbit
Eccentricity (e): 0.141
Orbit Range: 0.63 AU - 0.83 AU
Year: 238 Days
Day: 29.5 Hours
Environment
Temp: 131 °C
Axial Tilt: 34.2 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 3 - Terrestrial
Semi-Major Axis: 0.74 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.94
Radius: 1.89
Gravity: 1.38 G
Time & Orbit
Eccentricity (e): 0.232
Orbit Range: 0.57 AU - 0.91 AU
Year: 242 Days
Day: 38.5 Hours
Environment
Temp: 151 °C
Axial Tilt: 44.2 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (1)
Outer Limit: 48,730,929 km
- M1: 638,783 km (0.111 R)
Planet 4 - Terrestrial
Semi-Major Axis: 0.83 AU
Status: HZ
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.3
Radius: 1.11
Gravity: 1.06 G
Time & Orbit
Eccentricity (e): 0.014
Orbit Range: 0.82 AU - 0.84 AU
Year: 288 Days
Day: 19.1 Hours
Environment
Temp: 50 °C
Axial Tilt: 39.4 °
Atmosphere: Nâ‚‚, Oâ‚‚
Biome: Arid/Tundra
Planet 5 - Gas Giant
Semi-Major Axis: 4.91 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 347.7
Radius: 13.5
Gravity: 1.91 G
Time & Orbit
Eccentricity (e): 0.096
Orbit Range: 4.44 AU - 5.38 AU
Year: 4143 Days
Day: 11 Hours
Environment
Temp: -141 °C
Axial Tilt: 21.5 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (65)
Outer Limit: 48,730,929 km
- M1: 311,912 km (0.077 R)
- M2: 417,827 km (0.103 R)
- M3: 541,694 km (0.118 R)
- M4: 746,643 km (0.065 R)
- M5: 1,236,875 km (0.067 R)
- M6: 1,331,870 km (0.028 R)
- M7: 1,454,390 km (0.088 R)
- M8: 1,684,921 km (0.087 R)
- M9: 2,011,194 km (0.109 R)
- M10: 2,153,312 km (0.07 R)
- M11: 2,284,210 km (0.032 R)
- M12: 2,478,089 km (0.089 R)
- M13: 2,771,600 km (0.064 R)
- M14: 3,142,004 km (0.095 R)
- M15: 3,241,337 km (0.065 R)
- M16: 3,426,240 km (0.12 R)
- M17: 3,631,937 km (0.074 R)
- M18: 3,948,337 km (0.098 R)
- M19: 4,073,849 km (0.115 R)
- M20: 4,255,461 km (0.11 R)
- M21: 4,347,314 km (0.099 R)
- M22: 4,816,752 km (0.103 R)
- M23: 5,282,750 km (0.062 R)
- M24: 5,381,634 km (0.09 R)
- M25: 5,742,913 km (0.106 R)
- M26: 6,091,625 km (0.095 R)
- M27: 6,595,621 km (0.116 R)
- M28: 7,091,238 km (0.114 R)
- M29: 7,465,383 km (0.11 R)
- M30: 7,576,683 km (0.101 R)
- M31: 8,463,799 km (0.083 R)
- M32: 8,556,699 km (0.084 R)
- M33: 8,696,723 km (0.073 R)
- M34: 8,978,864 km (0.08 R)
- M35: 9,121,132 km (0.115 R)
- M36: 9,431,847 km (0.115 R)
- M37: 9,673,298 km (0.117 R)
- M38: 9,916,843 km (0.042 R)
- M39: 10,385,084 km (0.098 R)
- M40: 10,759,976 km (0.037 R)
- M41: 10,987,066 km (0.099 R)
- M42: 11,807,162 km (0.102 R)
- M43: 11,911,132 km (0.088 R)
- M44: 12,119,971 km (0.094 R)
- M45: 12,860,181 km (0.057 R)
- M46: 13,370,908 km (0.072 R)
- M47: 14,163,178 km (0.112 R)
- M48: 14,942,733 km (0.065 R)
- M49: 15,252,700 km (0.091 R)
- M50: 15,508,063 km (0.077 R)
- M51: 15,650,480 km (0.105 R)
- M52: 15,736,050 km (0.084 R)
- M53: 16,080,425 km (0.097 R)
- M54: 16,398,171 km (0.106 R)
- M55: 16,951,832 km (0.099 R)
- M56: 17,098,588 km (0.116 R)
- M57: 17,304,883 km (0.093 R)
- M58: 17,749,339 km (0.06 R)
- M59: 17,838,798 km (0.098 R)
- M60: 18,077,855 km (0.067 R)
- M61: 18,317,960 km (0.112 R)
- M62: 19,688,426 km (0.097 R)
- M63: 20,059,429 km (0.119 R)
- M64: 20,871,297 km (0.047 R)
- M65: 21,028,673 km (0.113 R)
Planet 6 - Gas Giant
Semi-Major Axis: 5.03 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 49.8
Radius: 8.6
Gravity: 0.67 G
Time & Orbit
Eccentricity (e): 0.072
Orbit Range: 4.67 AU - 5.39 AU
Year: 4296 Days
Day: 13.5 Hours
Environment
Temp: -156 °C
Axial Tilt: 26.9 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (62)
Outer Limit: 48,730,929 km
- M1: 127,607 km (0.118 R)
- M2: 211,083 km (0.098 R)
- M3: 276,906 km (0.059 R)
- M4: 453,132 km (0.115 R)
- M5: 529,876 km (0.077 R)
- M6: 795,412 km (0.1 R)
- M7: 849,417 km (0.086 R)
- M8: 990,188 km (0.109 R)
- M9: 1,184,965 km (0.052 R)
- M10: 1,367,773 km (0.067 R)
- M11: 1,425,219 km (0.032 R)
- M12: 1,483,562 km (0.041 R)
- M13: 1,725,163 km (0.089 R)
- M14: 1,805,497 km (0.089 R)
- M15: 2,016,729 km (0.039 R)
- M16: 2,120,699 km (0.111 R)
- M17: 2,333,876 km (0.079 R)
- M18: 2,453,255 km (0.092 R)
- M19: 2,666,881 km (0.107 R)
- M20: 2,739,436 km (0.118 R)
- M21: 2,918,505 km (0.114 R)
- M22: 3,321,671 km (0.12 R)
- M23: 3,411,131 km (0.107 R)
- M24: 3,501,488 km (0.067 R)
- M25: 3,627,000 km (0.108 R)
- M26: 3,765,678 km (0.067 R)
- M27: 3,859,027 km (0.059 R)
- M28: 3,941,455 km (0.09 R)
- M29: 4,048,268 km (0.039 R)
- M30: 4,167,946 km (0.118 R)
- M31: 4,522,044 km (0.118 R)
- M32: 4,608,961 km (0.113 R)
- M33: 4,822,437 km (0.051 R)
- M34: 5,390,011 km (0.113 R)
- M35: 5,924,375 km (0.108 R)
- M36: 6,033,282 km (0.059 R)
- M37: 6,088,035 km (0.064 R)
- M38: 6,211,752 km (0.045 R)
- M39: 6,322,305 km (0.073 R)
- M40: 6,377,956 km (0.119 R)
- M41: 6,601,904 km (0.045 R)
- M42: 6,729,062 km (0.086 R)
- M43: 7,129,685 km (0.119 R)
- M44: 7,611,839 km (0.078 R)
- M45: 7,700,700 km (0.099 R)
- M46: 7,775,050 km (0.078 R)
- M47: 8,044,326 km (0.113 R)
- M48: 8,638,529 km (0.096 R)
- M49: 8,777,655 km (0.092 R)
- M50: 8,948,795 km (0.1 R)
- M51: 9,026,885 km (0.073 R)
- M52: 9,405,069 km (0.05 R)
- M53: 9,500,512 km (0.086 R)
- M54: 9,740,317 km (0.085 R)
- M55: 9,901,285 km (0.103 R)
- M56: 9,965,911 km (0.107 R)
- M57: 10,111,918 km (0.088 R)
- M58: 10,209,606 km (0.099 R)
- M59: 10,291,286 km (0.081 R)
- M60: 10,719,585 km (0.106 R)
- M61: 11,002,624 km (0.094 R)
- M62: 11,372,729 km (0.078 R)
Planet 7 - Gas Giant
Semi-Major Axis: 8.12 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 581.7
Radius: 10.4
Gravity: 5.38 G
Time & Orbit
Eccentricity (e): 0.187
Orbit Range: 6.6 AU - 9.64 AU
Year: 8811 Days
Day: 6.3 Hours
Environment
Temp: -169 °C
Axial Tilt: 10.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (82)
Outer Limit: 48,730,929 km
- M1: 139,874 km (0.101 R)
- M2: 213,476 km (0.118 R)
- M3: 526,285 km (0.104 R)
- M4: 850,613 km (0.073 R)
- M5: 1,424,770 km (0.109 R)
- M6: 1,836,613 km (0.088 R)
- M7: 1,923,380 km (0.027 R)
- M8: 1,989,352 km (0.114 R)
- M9: 2,521,323 km (0.111 R)
- M10: 2,667,180 km (0.063 R)
- M11: 3,018,735 km (0.06 R)
- M12: 3,331,844 km (0.093 R)
- M13: 3,519,440 km (0.095 R)
- M14: 3,600,970 km (0.047 R)
- M15: 3,821,328 km (0.115 R)
- M16: 4,017,750 km (0.12 R)
- M17: 4,450,088 km (0.106 R)
- M18: 4,567,971 km (0.09 R)
- M19: 4,836,948 km (0.096 R)
- M20: 5,611,117 km (0.101 R)
- M21: 6,028,944 km (0.036 R)
- M22: 6,725,322 km (0.102 R)
- M23: 7,100,214 km (0.077 R)
- M24: 7,693,071 km (0.099 R)
- M25: 8,049,113 km (0.098 R)
- M26: 8,121,070 km (0.09 R)
- M27: 8,926,056 km (0.079 R)
- M28: 9,413,596 km (0.045 R)
- M29: 9,489,442 km (0.103 R)
- M30: 9,565,288 km (0.08 R)
- M31: 9,679,730 km (0.11 R)
- M32: 10,141,838 km (0.065 R)
- M33: 10,258,524 km (0.035 R)
- M34: 11,368,690 km (0.109 R)
- M35: 11,449,323 km (0.103 R)
- M36: 11,570,947 km (0.093 R)
- M37: 12,061,179 km (0.048 R)
- M38: 12,350,351 km (0.108 R)
- M39: 12,558,292 km (0.115 R)
- M40: 12,725,543 km (0.091 R)
- M41: 13,787,239 km (0.101 R)
- M42: 15,009,902 km (0.114 R)
- M43: 15,187,475 km (0.07 R)
- M44: 15,904,348 km (0.109 R)
- M45: 16,267,123 km (0.077 R)
- M46: 16,403,706 km (0.07 R)
- M47: 17,046,677 km (0.11 R)
- M48: 17,278,404 km (0.106 R)
- M49: 17,557,704 km (0.059 R)
- M50: 18,928,918 km (0.118 R)
- M51: 21,422,714 km (0.05 R)
- M52: 21,722,808 km (0.098 R)
- M53: 21,823,188 km (0.092 R)
- M54: 22,530,038 km (0.108 R)
- M55: 23,398,453 km (0.105 R)
- M56: 23,655,911 km (0.084 R)
- M57: 23,966,177 km (0.049 R)
- M58: 24,173,670 km (0.092 R)
- M59: 24,590,748 km (0.109 R)
- M60: 24,852,545 km (0.102 R)
- M61: 25,062,580 km (0.111 R)
- M62: 26,282,102 km (0.098 R)
- M63: 26,764,705 km (0.056 R)
- M64: 27,141,990 km (0.109 R)
- M65: 28,065,608 km (0.102 R)
- M66: 29,387,006 km (0.091 R)
- M67: 29,553,658 km (0.116 R)
- M68: 29,887,710 km (0.095 R)
- M69: 31,180,235 km (0.114 R)
- M70: 31,690,963 km (0.075 R)
- M71: 32,605,754 km (0.065 R)
- M72: 32,951,025 km (0.096 R)
- M73: 35,224,913 km (0.085 R)
- M74: 35,638,402 km (0.097 R)
- M75: 35,875,365 km (0.063 R)
- M76: 36,589,395 km (0.081 R)
- M77: 38,031,668 km (0.091 R)
- M78: 39,003,606 km (0.067 R)
- M79: 39,676,347 km (0.094 R)
- M80: 40,291,494 km (0.07 R)
- M81: 41,033,649 km (0.054 R)
- M82: 41,282,131 km (0.067 R)
Planet 8 - Gas Giant
Semi-Major Axis: 8.45 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 700.1
Radius: 13.3
Gravity: 3.96 G
Time & Orbit
Eccentricity (e): 0.002
Orbit Range: 8.43 AU - 8.47 AU
Year: 9354 Days
Day: 8.4 Hours
Environment
Temp: -172 °C
Axial Tilt: 13.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (86)
Outer Limit: 48,730,929 km
- M1: 181,612 km (0.099 R)
- M2: 285,882 km (0.084 R)
- M3: 428,747 km (0.09 R)
- M4: 858,692 km (0.067 R)
- M5: 1,054,366 km (0.095 R)
- M6: 1,325,886 km (0.105 R)
- M7: 1,577,061 km (0.066 R)
- M8: 1,708,707 km (0.096 R)
- M9: 1,959,882 km (0.082 R)
- M10: 2,150,320 km (0.072 R)
- M11: 2,272,541 km (0.044 R)
- M12: 2,653,567 km (0.109 R)
- M13: 2,973,258 km (0.1 R)
- M14: 3,505,078 km (0.091 R)
- M15: 3,708,681 km (0.101 R)
- M16: 4,219,408 km (0.088 R)
- M17: 4,530,422 km (0.077 R)
- M18: 4,752,575 km (0.082 R)
- M19: 4,913,542 km (0.064 R)
- M20: 5,174,890 km (0.107 R)
- M21: 5,779,564 km (0.101 R)
- M22: 5,882,637 km (0.11 R)
- M23: 5,986,308 km (0.074 R)
- M24: 6,801,018 km (0.085 R)
- M25: 7,726,132 km (0.11 R)
- M26: 8,030,713 km (0.09 R)
- M27: 8,730,083 km (0.095 R)
- M28: 9,611,514 km (0.104 R)
- M29: 10,021,561 km (0.112 R)
- M30: 10,353,818 km (0.092 R)
- M31: 10,479,331 km (0.102 R)
- M32: 10,605,442 km (0.029 R)
- M33: 10,774,188 km (0.062 R)
- M34: 11,937,162 km (0.06 R)
- M35: 12,734,668 km (0.082 R)
- M36: 12,824,277 km (0.114 R)
- M37: 13,185,108 km (0.079 R)
- M38: 13,275,913 km (0.105 R)
- M39: 13,824,638 km (0.098 R)
- M40: 14,287,644 km (0.119 R)
- M41: 15,467,373 km (0.038 R)
- M42: 15,803,369 km (0.092 R)
- M43: 15,948,031 km (0.12 R)
- M44: 16,093,290 km (0.059 R)
- M45: 16,580,231 km (0.107 R)
- M46: 16,727,286 km (0.107 R)
- M47: 17,618,889 km (0.1 R)
- M48: 17,969,846 km (0.071 R)
- M49: 18,525,901 km (0.106 R)
- M50: 19,706,976 km (0.054 R)
- M51: 21,657,583 km (0.11 R)
- M52: 21,872,106 km (0.083 R)
- M53: 23,834,830 km (0.102 R)
- M54: 24,613,338 km (0.073 R)
- M55: 24,781,186 km (0.025 R)
- M56: 26,081,042 km (0.119 R)
- M57: 27,403,039 km (0.071 R)
- M58: 28,982,643 km (0.09 R)
- M59: 29,694,130 km (0.103 R)
- M60: 30,171,647 km (0.097 R)
- M61: 30,351,463 km (0.109 R)
- M62: 30,772,282 km (0.087 R)
- M63: 31,194,896 km (0.055 R)
- M64: 31,558,868 km (0.115 R)
- M65: 31,680,341 km (0.03 R)
- M66: 32,658,861 km (0.082 R)
- M67: 32,904,949 km (0.049 R)
- M68: 33,090,002 km (0.065 R)
- M69: 33,461,154 km (0.094 R)
- M70: 35,022,208 km (0.062 R)
- M71: 35,400,391 km (0.118 R)
- M72: 35,779,921 km (0.064 R)
- M73: 36,224,526 km (0.061 R)
- M74: 36,606,898 km (0.071 R)
- M75: 37,054,794 km (0.098 R)
- M76: 37,697,915 km (0.093 R)
- M77: 38,864,629 km (0.064 R)
- M78: 39,256,127 km (0.116 R)
- M79: 39,517,923 km (0.103 R)
- M80: 39,911,665 km (0.11 R)
- M81: 40,636,915 km (0.078 R)
- M82: 41,366,504 km (0.062 R)
- M83: 42,167,451 km (0.026 R)
- M84: 42,637,039 km (0.088 R)
- M85: 43,513,533 km (0.093 R)
- M86: 44,191,959 km (0.029 R)
Planet 9 - Gas Giant
Semi-Major Axis: 8.45 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 822.7
Radius: 8.7
Gravity: 10.87 G
Time & Orbit
Eccentricity (e): 0.027
Orbit Range: 8.22 AU - 8.68 AU
Year: 9354 Days
Day: 6.8 Hours
Environment
Temp: -167 °C
Axial Tilt: 6.4 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (95)
Outer Limit: 48,730,929 km
- M1: 335,997 km (0.116 R)
- M2: 556,953 km (0.118 R)
- M3: 822,788 km (0.106 R)
- M4: 877,092 km (0.075 R)
- M5: 1,067,231 km (0.082 R)
- M6: 1,399,189 km (0.067 R)
- M7: 1,955,095 km (0.099 R)
- M8: 2,205,671 km (0.071 R)
- M9: 2,876,617 km (0.096 R)
- M10: 2,961,140 km (0.092 R)
- M11: 3,396,769 km (0.095 R)
- M12: 3,821,328 km (0.096 R)
- M13: 3,977,209 km (0.069 R)
- M14: 4,295,104 km (0.102 R)
- M15: 4,457,119 km (0.11 R)
- M16: 4,588,316 km (0.118 R)
- M17: 4,787,431 km (0.06 R)
- M18: 4,921,620 km (0.057 R)
- M19: 5,125,522 km (0.069 R)
- M20: 5,541,554 km (0.081 R)
- M21: 5,789,288 km (0.118 R)
- M22: 6,186,022 km (0.067 R)
- M23: 6,591,581 km (0.09 R)
- M24: 6,703,630 km (0.04 R)
- M25: 7,043,816 km (0.102 R)
- M26: 7,662,403 km (0.094 R)
- M27: 7,859,274 km (0.088 R)
- M28: 8,868,611 km (0.081 R)
- M29: 8,951,189 km (0.079 R)
- M30: 9,158,531 km (0.046 R)
- M31: 10,349,181 km (0.102 R)
- M32: 11,095,674 km (0.11 R)
- M33: 11,229,265 km (0.035 R)
- M34: 11,318,575 km (0.11 R)
- M35: 11,678,208 km (0.054 R)
- M36: 12,041,731 km (0.074 R)
- M37: 12,733,172 km (0.066 R)
- M38: 13,201,264 km (0.08 R)
- M39: 13,342,933 km (0.12 R)
- M40: 13,532,324 km (0.099 R)
- M41: 13,770,484 km (0.048 R)
- M42: 14,493,341 km (0.077 R)
- M43: 14,590,580 km (0.064 R)
- M44: 14,688,117 km (0.092 R)
- M45: 15,080,363 km (0.098 R)
- M46: 16,126,501 km (0.089 R)
- M47: 16,480,449 km (0.072 R)
- M48: 17,298,899 km (0.085 R)
- M49: 18,551,333 km (0.112 R)
- M50: 18,710,056 km (0.044 R)
- M51: 19,348,989 km (0.044 R)
- M52: 19,563,512 km (0.092 R)
- M53: 20,320,776 km (0.106 R)
- M54: 20,648,246 km (0.1 R)
- M55: 21,696,778 km (0.103 R)
- M56: 23,330,237 km (0.098 R)
- M57: 23,730,561 km (0.1 R)
- M58: 24,075,384 km (0.095 R)
- M59: 24,248,319 km (0.12 R)
- M60: 24,306,213 km (0.096 R)
- M61: 25,003,040 km (0.098 R)
- M62: 25,942,365 km (0.047 R)
- M63: 27,192,854 km (0.091 R)
- M64: 28,280,131 km (0.095 R)
- M65: 28,584,712 km (0.09 R)
- M66: 28,951,526 km (0.113 R)
- M67: 29,320,135 km (0.083 R)
- M68: 29,875,742 km (0.086 R)
- M69: 30,061,692 km (0.079 R)
- M70: 31,437,245 km (0.079 R)
- M71: 32,196,304 km (0.086 R)
- M72: 32,961,198 km (0.116 R)
- M73: 33,538,945 km (0.075 R)
- M74: 33,925,805 km (0.109 R)
- M75: 34,314,311 km (0.106 R)
- M76: 34,444,162 km (0.06 R)
- M77: 35,751,198 km (0.037 R)
- M78: 35,817,021 km (0.077 R)
- M79: 36,014,640 km (0.076 R)
- M80: 36,080,613 km (0.118 R)
- M81: 37,074,541 km (0.114 R)
- M82: 37,141,112 km (0.117 R)
- M83: 37,876,236 km (0.05 R)
- M84: 38,077,595 km (0.075 R)
- M85: 38,818,703 km (0.045 R)
- M86: 38,886,321 km (0.11 R)
- M87: 39,564,598 km (0.025 R)
- M88: 41,415,572 km (0.113 R)
- M89: 42,177,773 km (0.062 R)
- M90: 43,084,486 km (0.114 R)
- M91: 45,059,178 km (0.108 R)
- M92: 45,201,296 km (0.059 R)
- M93: 46,703,109 km (0.064 R)
- M94: 47,858,304 km (0.084 R)
- M95: 48,658,054 km (0.082 R)
Kuiper Belt
Range: 30 - 59 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 204 - 18,465 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.