G4V Star System Generated (Seed: 1768423349)
Star Details
Spectral Class: G5V
Temperature: 5,600 K
Mass: 1 sol
Luminosity: 1 lux
Habitable Zone (HZ)
Inner Boundary: 0.95 AU
Outer Boundary: 1.37 AU
Physical Limits
Snow Line: 4.8 AU
Max System Radius: 20 AU
Planetary System (10 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.69 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.22
Radius: 1.08
Gravity: 1.05 G
Time & Orbit
Eccentricity (e): 0.09
Orbit Range: 0.63 AU - 0.75 AU
Year: 209 Days
Day: 46.3 Hours
Environment
Temp: 123 °C
Axial Tilt: 44.5 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 2 - Terrestrial
Semi-Major Axis: 0.75 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.9
Radius: 1.53
Gravity: 1.24 G
Time & Orbit
Eccentricity (e): 0.101
Orbit Range: 0.67 AU - 0.83 AU
Year: 237 Days
Day: 13.2 Hours
Environment
Temp: 138 °C
Axial Tilt: 9.5 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (2)
Outer Limit: 70,090,384 km
- M1: 358,287 km (0.116 R)
- M2: 634,744 km (0.096 R)
Planet 3 - Terrestrial
Semi-Major Axis: 0.9 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.76
Radius: 1.5
Gravity: 1.23 G
Time & Orbit
Eccentricity (e): 0.208
Orbit Range: 0.71 AU - 1.09 AU
Year: 312 Days
Day: 16.1 Hours
Environment
Temp: 70 °C
Axial Tilt: 36.1 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 4 - Terrestrial
Semi-Major Axis: 1.94 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.74
Radius: 1.5
Gravity: 1.22 G
Time & Orbit
Eccentricity (e): 0.045
Orbit Range: 1.85 AU - 2.03 AU
Year: 987 Days
Day: 47.6 Hours
Environment
Temp: -60 °C
Axial Tilt: 61.8 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 5 - Terrestrial
Semi-Major Axis: 2.51 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.32
Radius: 1.4
Gravity: 1.18 G
Time & Orbit
Eccentricity (e): 0.003
Orbit Range: 2.5 AU - 2.52 AU
Year: 1452 Days
Day: 21.8 Hours
Environment
Temp: -90 °C
Axial Tilt: 23.4 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 70,090,384 km
- M1: 1,479,972 km (0.05 R)
Planet 6 - Gas Giant
Semi-Major Axis: 5.6 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 490.1
Radius: 10.3
Gravity: 4.62 G
Time & Orbit
Eccentricity (e): 0.036
Orbit Range: 5.4 AU - 5.8 AU
Year: 4840 Days
Day: 9.5 Hours
Environment
Temp: -140 °C
Axial Tilt: 16.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (80)
Outer Limit: 70,090,384 km
- M1: 140,323 km (0.072 R)
- M2: 208,091 km (0.074 R)
- M3: 278,701 km (0.091 R)
- M4: 346,469 km (0.119 R)
- M5: 495,468 km (0.05 R)
- M6: 803,041 km (0.11 R)
- M7: 1,127,070 km (0.11 R)
- M8: 1,702,125 km (0.111 R)
- M9: 1,858,903 km (0.112 R)
- M10: 2,053,530 km (0.095 R)
- M11: 2,358,111 km (0.079 R)
- M12: 2,445,327 km (0.096 R)
- M13: 2,805,110 km (0.063 R)
- M14: 3,220,393 km (0.115 R)
- M15: 3,356,677 km (0.079 R)
- M16: 3,475,009 km (0.111 R)
- M17: 3,594,837 km (0.075 R)
- M18: 4,045,725 km (0.057 R)
- M19: 4,889,008 km (0.114 R)
- M20: 5,411,404 km (0.113 R)
- M21: 5,504,154 km (0.104 R)
- M22: 5,667,665 km (0.088 R)
- M23: 6,023,409 km (0.057 R)
- M24: 6,143,685 km (0.086 R)
- M25: 6,657,404 km (0.102 R)
- M26: 6,856,669 km (0.082 R)
- M27: 7,210,318 km (0.097 R)
- M28: 7,544,071 km (0.077 R)
- M29: 7,673,922 km (0.108 R)
- M30: 8,014,706 km (0.072 R)
- M31: 8,226,836 km (0.086 R)
- M32: 8,387,205 km (0.088 R)
- M33: 8,575,548 km (0.103 R)
- M34: 9,426,910 km (0.098 R)
- M35: 9,566,634 km (0.104 R)
- M36: 10,161,435 km (0.065 R)
- M37: 10,276,177 km (0.062 R)
- M38: 10,973,153 km (0.086 R)
- M39: 11,805,666 km (0.071 R)
- M40: 11,956,460 km (0.031 R)
- M41: 12,138,371 km (0.119 R)
- M42: 12,843,875 km (0.036 R)
- M43: 13,373,750 km (0.116 R)
- M44: 13,942,821 km (0.112 R)
- M45: 14,551,983 km (0.118 R)
- M46: 14,713,699 km (0.089 R)
- M47: 14,973,849 km (0.094 R)
- M48: 15,235,346 km (0.102 R)
- M49: 15,895,971 km (0.081 R)
- M50: 15,962,542 km (0.078 R)
- M51: 16,397,572 km (0.105 R)
- M52: 16,599,679 km (0.088 R)
- M53: 16,701,106 km (0.102 R)
- M54: 17,416,334 km (0.118 R)
- M55: 17,795,116 km (0.059 R)
- M56: 18,315,866 km (0.083 R)
- M57: 19,159,598 km (0.083 R)
- M58: 19,443,534 km (0.098 R)
- M59: 20,775,404 km (0.119 R)
- M60: 21,287,029 km (0.117 R)
- M61: 21,876,744 km (0.081 R)
- M62: 22,062,245 km (0.073 R)
- M63: 22,471,994 km (0.048 R)
- M64: 22,584,192 km (0.112 R)
- M65: 22,734,089 km (0.114 R)
- M66: 22,846,587 km (0.095 R)
- M67: 23,034,781 km (0.046 R)
- M68: 23,223,424 km (0.093 R)
- M69: 23,488,362 km (0.111 R)
- M70: 23,564,208 km (0.103 R)
- M71: 23,868,639 km (0.111 R)
- M72: 24,174,268 km (0.045 R)
- M73: 24,365,903 km (0.082 R)
- M74: 25,060,336 km (0.059 R)
- M75: 25,409,946 km (0.117 R)
- M76: 25,565,827 km (0.11 R)
- M77: 25,682,962 km (0.04 R)
- M78: 25,956,876 km (0.097 R)
- M79: 26,231,987 km (0.12 R)
- M80: 26,429,007 km (0.055 R)
Planet 7 - Gas Giant
Semi-Major Axis: 5.68 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 722.5
Radius: 13.7
Gravity: 3.85 G
Time & Orbit
Eccentricity (e): 0.044
Orbit Range: 5.43 AU - 5.93 AU
Year: 4944 Days
Day: 6.9 Hours
Environment
Temp: -147 °C
Axial Tilt: 2.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (72)
Outer Limit: 70,090,384 km
- M1: 184,454 km (0.074 R)
- M2: 283,189 km (0.115 R)
- M3: 404,064 km (0.1 R)
- M4: 509,530 km (0.052 R)
- M5: 781,050 km (0.042 R)
- M6: 895,792 km (0.05 R)
- M7: 1,158,636 km (0.104 R)
- M8: 1,368,970 km (0.089 R)
- M9: 1,527,245 km (0.088 R)
- M10: 1,625,381 km (0.101 R)
- M11: 1,793,828 km (0.062 R)
- M12: 2,148,525 km (0.085 R)
- M13: 2,372,323 km (0.049 R)
- M14: 2,584,453 km (0.09 R)
- M15: 3,365,204 km (0.039 R)
- M16: 3,804,573 km (0.084 R)
- M17: 3,917,220 km (0.08 R)
- M18: 4,054,102 km (0.092 R)
- M19: 4,761,999 km (0.11 R)
- M20: 4,908,306 km (0.059 R)
- M21: 5,080,942 km (0.065 R)
- M22: 5,180,425 km (0.09 R)
- M23: 5,533,924 km (0.097 R)
- M24: 5,688,010 km (0.117 R)
- M25: 6,184,974 km (0.103 R)
- M26: 6,318,266 km (0.091 R)
- M27: 6,533,238 km (0.091 R)
- M28: 6,750,754 km (0.071 R)
- M29: 7,137,314 km (0.104 R)
- M30: 7,845,511 km (0.12 R)
- M31: 8,047,767 km (0.117 R)
- M32: 8,904,514 km (0.108 R)
- M33: 9,977,131 km (0.096 R)
- M34: 10,228,006 km (0.116 R)
- M35: 11,513,800 km (0.104 R)
- M36: 11,777,092 km (0.105 R)
- M37: 12,444,000 km (0.081 R)
- M38: 12,612,746 km (0.111 R)
- M39: 13,054,808 km (0.089 R)
- M40: 13,432,842 km (0.096 R)
- M41: 13,919,334 km (0.059 R)
- M42: 14,129,668 km (0.089 R)
- M43: 14,305,596 km (0.111 R)
- M44: 14,517,875 km (0.093 R)
- M45: 14,624,389 km (0.11 R)
- M46: 14,981,180 km (0.086 R)
- M47: 15,922,599 km (0.081 R)
- M48: 16,326,663 km (0.119 R)
- M49: 16,437,365 km (0.093 R)
- M50: 16,734,018 km (0.11 R)
- M51: 17,219,912 km (0.084 R)
- M52: 18,474,140 km (0.084 R)
- M53: 19,209,563 km (0.119 R)
- M54: 20,073,042 km (0.105 R)
- M55: 20,669,190 km (0.092 R)
- M56: 21,311,413 km (0.074 R)
- M57: 23,152,664 km (0.101 R)
- M58: 23,903,496 km (0.071 R)
- M59: 24,746,929 km (0.095 R)
- M60: 25,087,114 km (0.083 R)
- M61: 25,944,310 km (0.062 R)
- M62: 26,116,946 km (0.074 R)
- M63: 26,289,881 km (0.077 R)
- M64: 26,898,296 km (0.113 R)
- M65: 27,379,701 km (0.065 R)
- M66: 27,819,669 km (0.04 R)
- M67: 27,907,932 km (0.042 R)
- M68: 28,173,318 km (0.043 R)
- M69: 28,262,030 km (0.06 R)
- M70: 28,439,602 km (0.098 R)
- M71: 29,423,208 km (0.091 R)
- M72: 30,145,467 km (0.106 R)
Planet 8 - Gas Giant
Semi-Major Axis: 6.52 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 288
Radius: 10.3
Gravity: 2.71 G
Time & Orbit
Eccentricity (e): 0.059
Orbit Range: 6.14 AU - 6.9 AU
Year: 6081 Days
Day: 5.9 Hours
Environment
Temp: -162 °C
Axial Tilt: 41 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (50)
Outer Limit: 70,090,384 km
- M1: 132,245 km (0.109 R)
- M2: 310,565 km (0.115 R)
- M3: 514,467 km (0.088 R)
- M4: 686,804 km (0.092 R)
- M5: 786,137 km (0.072 R)
- M6: 1,316,312 km (0.113 R)
- M7: 1,457,083 km (0.106 R)
- M8: 1,588,281 km (0.075 R)
- M9: 2,070,285 km (0.098 R)
- M10: 2,543,313 km (0.12 R)
- M11: 3,449,876 km (0.106 R)
- M12: 3,527,967 km (0.081 R)
- M13: 3,766,126 km (0.093 R)
- M14: 4,857,742 km (0.063 R)
- M15: 5,257,318 km (0.109 R)
- M16: 5,552,475 km (0.089 R)
- M17: 5,946,815 km (0.116 R)
- M18: 6,064,548 km (0.113 R)
- M19: 6,159,244 km (0.076 R)
- M20: 6,302,259 km (0.069 R)
- M21: 6,470,557 km (0.109 R)
- M22: 6,640,350 km (0.06 R)
- M23: 6,934,759 km (0.095 R)
- M24: 7,511,159 km (0.09 R)
- M25: 8,129,148 km (0.111 R)
- M26: 8,790,221 km (0.097 R)
- M27: 8,924,560 km (0.109 R)
- M28: 9,468,498 km (0.085 R)
- M29: 10,990,656 km (0.111 R)
- M30: 11,077,423 km (0.111 R)
- M31: 11,164,339 km (0.114 R)
- M32: 12,076,887 km (0.044 R)
- M33: 12,890,998 km (0.107 R)
- M34: 13,754,028 km (0.071 R)
- M35: 13,878,942 km (0.046 R)
- M36: 14,098,253 km (0.079 R)
- M37: 14,858,958 km (0.114 R)
- M38: 14,955,000 km (0.03 R)
- M39: 15,212,159 km (0.095 R)
- M40: 15,438,351 km (0.07 R)
- M41: 19,450,266 km (0.085 R)
- M42: 19,871,833 km (0.088 R)
- M43: 19,977,748 km (0.074 R)
- M44: 20,474,264 km (0.115 R)
- M45: 21,479,561 km (0.108 R)
- M46: 21,842,336 km (0.115 R)
- M47: 22,024,547 km (0.067 R)
- M48: 23,054,378 km (0.09 R)
- M49: 23,351,480 km (0.068 R)
- M50: 25,351,603 km (0.107 R)
Planet 9 - Gas Giant
Semi-Major Axis: 9.05 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 497.8
Radius: 13.2
Gravity: 2.86 G
Time & Orbit
Eccentricity (e): 0.183
Orbit Range: 7.39 AU - 10.71 AU
Year: 9944 Days
Day: 10.5 Hours
Environment
Temp: -173 °C
Axial Tilt: 16.6 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (81)
Outer Limit: 70,090,384 km
- M1: 250,726 km (0.097 R)
- M2: 905,815 km (0.057 R)
- M3: 1,150,108 km (0.031 R)
- M4: 1,377,198 km (0.11 R)
- M5: 1,853,966 km (0.111 R)
- M6: 2,009,099 km (0.08 R)
- M7: 2,099,905 km (0.115 R)
- M8: 2,648,780 km (0.086 R)
- M9: 3,162,050 km (0.074 R)
- M10: 3,376,125 km (0.059 R)
- M11: 3,567,311 km (0.093 R)
- M12: 4,457,717 km (0.07 R)
- M13: 4,912,644 km (0.089 R)
- M14: 5,005,395 km (0.078 R)
- M15: 6,365,689 km (0.096 R)
- M16: 6,671,467 km (0.093 R)
- M17: 8,235,213 km (0.073 R)
- M18: 8,680,716 km (0.117 R)
- M19: 9,248,739 km (0.117 R)
- M20: 9,363,929 km (0.115 R)
- M21: 9,479,419 km (0.079 R)
- M22: 10,025,002 km (0.062 R)
- M23: 10,381,195 km (0.113 R)
- M24: 10,500,873 km (0.065 R)
- M25: 11,228,367 km (0.096 R)
- M26: 12,097,830 km (0.119 R)
- M27: 12,308,015 km (0.058 R)
- M28: 12,477,061 km (0.098 R)
- M29: 13,682,072 km (0.108 R)
- M30: 14,209,853 km (0.091 R)
- M31: 14,879,004 km (0.113 R)
- M32: 15,104,299 km (0.088 R)
- M33: 15,695,509 km (0.096 R)
- M34: 15,832,990 km (0.103 R)
- M35: 17,135,838 km (0.094 R)
- M36: 17,419,475 km (0.082 R)
- M37: 17,561,892 km (0.114 R)
- M38: 18,183,472 km (0.115 R)
- M39: 18,763,612 km (0.057 R)
- M40: 19,153,913 km (0.073 R)
- M41: 19,744,226 km (0.069 R)
- M42: 19,942,294 km (0.114 R)
- M43: 20,390,489 km (0.114 R)
- M44: 21,246,039 km (0.109 R)
- M45: 22,062,096 km (0.108 R)
- M46: 22,370,716 km (0.092 R)
- M47: 22,525,699 km (0.117 R)
- M48: 23,357,613 km (0.071 R)
- M49: 24,252,657 km (0.067 R)
- M50: 24,571,301 km (0.105 R)
- M51: 24,998,253 km (0.082 R)
- M52: 26,949,608 km (0.071 R)
- M53: 27,059,562 km (0.039 R)
- M54: 27,445,225 km (0.1 R)
- M55: 27,555,629 km (0.09 R)
- M56: 27,666,331 km (0.038 R)
- M57: 28,613,136 km (0.105 R)
- M58: 29,005,980 km (0.116 R)
- M59: 29,287,673 km (0.111 R)
- M60: 29,570,413 km (0.048 R)
- M61: 29,683,658 km (0.118 R)
- M62: 29,853,901 km (0.101 R)
- M63: 30,309,576 km (0.107 R)
- M64: 30,423,869 km (0.114 R)
- M65: 30,767,495 km (0.052 R)
- M66: 31,285,403 km (0.027 R)
- M67: 32,446,432 km (0.082 R)
- M68: 32,914,972 km (0.062 R)
- M69: 33,208,783 km (0.117 R)
- M70: 33,444,549 km (0.066 R)
- M71: 33,799,245 km (0.11 R)
- M72: 34,155,139 km (0.081 R)
- M73: 35,290,437 km (0.093 R)
- M74: 36,256,091 km (0.079 R)
- M75: 37,352,793 km (0.109 R)
- M76: 37,475,314 km (0.108 R)
- M77: 39,954,001 km (0.103 R)
- M78: 40,644,993 km (0.106 R)
- M79: 40,770,955 km (0.086 R)
- M80: 41,276,446 km (0.086 R)
- M81: 41,530,014 km (0.102 R)
Planet 10 - Gas Giant
Semi-Major Axis: 11.8 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 977.1
Radius: 12.5
Gravity: 6.25 G
Time & Orbit
Eccentricity (e): 0.198
Orbit Range: 9.46 AU - 14.14 AU
Year: 14805 Days
Day: 14.9 Hours
Environment
Temp: -183 °C
Axial Tilt: 49.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (92)
Outer Limit: 70,090,384 km
- M1: 166,951 km (0.077 R)
- M2: 383,719 km (0.072 R)
- M3: 518,805 km (0.109 R)
- M4: 757,414 km (0.051 R)
- M5: 868,116 km (0.077 R)
- M6: 984,803 km (0.094 R)
- M7: 1,157,738 km (0.1 R)
- M8: 1,287,738 km (0.106 R)
- M9: 1,563,298 km (0.079 R)
- M10: 1,919,191 km (0.118 R)
- M11: 2,138,950 km (0.101 R)
- M12: 2,268,203 km (0.083 R)
- M13: 3,099,069 km (0.101 R)
- M14: 3,858,129 km (0.108 R)
- M15: 4,423,160 km (0.119 R)
- M16: 5,144,072 km (0.086 R)
- M17: 5,496,226 km (0.089 R)
- M18: 5,856,158 km (0.092 R)
- M19: 5,947,413 km (0.081 R)
- M20: 6,223,870 km (0.12 R)
- M21: 6,694,206 km (0.101 R)
- M22: 7,372,033 km (0.099 R)
- M23: 8,020,989 km (0.116 R)
- M24: 8,481,152 km (0.102 R)
- M25: 8,949,842 km (0.056 R)
- M26: 10,131,067 km (0.108 R)
- M27: 10,628,330 km (0.111 R)
- M28: 12,696,521 km (0.077 R)
- M29: 13,053,162 km (0.104 R)
- M30: 13,352,807 km (0.087 R)
- M31: 14,574,423 km (0.05 R)
- M32: 15,198,545 km (0.104 R)
- M33: 15,577,177 km (0.036 R)
- M34: 16,022,979 km (0.119 R)
- M35: 16,215,212 km (0.091 R)
- M36: 16,408,343 km (0.114 R)
- M37: 17,385,367 km (0.102 R)
- M38: 18,919,792 km (0.099 R)
- M39: 19,463,730 km (0.082 R)
- M40: 20,012,754 km (0.065 R)
- M41: 21,196,373 km (0.082 R)
- M42: 26,910,712 km (0.091 R)
- M43: 27,292,486 km (0.115 R)
- M44: 27,599,012 km (0.082 R)
- M45: 27,752,799 km (0.09 R)
- M46: 28,837,084 km (0.041 R)
- M47: 30,172,095 km (0.074 R)
- M48: 32,739,494 km (0.082 R)
- M49: 33,802,536 km (0.045 R)
- M50: 34,296,808 km (0.114 R)
- M51: 34,793,622 km (0.099 R)
- M52: 34,876,649 km (0.084 R)
- M53: 35,376,306 km (0.106 R)
- M54: 35,543,407 km (0.078 R)
- M55: 36,298,278 km (0.094 R)
- M56: 36,382,501 km (0.056 R)
- M57: 39,198,083 km (0.116 R)
- M58: 39,717,487 km (0.08 R)
- M59: 39,891,170 km (0.063 R)
- M60: 41,641,465 km (0.096 R)
- M61: 42,082,928 km (0.119 R)
- M62: 42,703,610 km (0.099 R)
- M63: 42,792,471 km (0.08 R)
- M64: 43,864,340 km (0.084 R)
- M65: 44,493,698 km (0.097 R)
- M66: 44,764,320 km (0.039 R)
- M67: 44,854,678 km (0.108 R)
- M68: 45,670,435 km (0.085 R)
- M69: 46,674,087 km (0.1 R)
- M70: 46,857,344 km (0.064 R)
- M71: 47,224,607 km (0.08 R)
- M72: 47,592,767 km (0.049 R)
- M73: 47,684,920 km (0.113 R)
- M74: 49,354,731 km (0.082 R)
- M75: 49,915,574 km (0.033 R)
- M76: 50,384,563 km (0.076 R)
- M77: 51,138,087 km (0.105 R)
- M78: 51,421,575 km (0.094 R)
- M79: 51,895,202 km (0.115 R)
- M80: 52,560,763 km (0.117 R)
- M81: 53,804,221 km (0.09 R)
- M82: 55,057,552 km (0.111 R)
- M83: 55,445,010 km (0.032 R)
- M84: 60,465,066 km (0.067 R)
- M85: 62,372,139 km (0.092 R)
- M86: 62,877,331 km (0.069 R)
- M87: 64,298,810 km (0.097 R)
- M88: 65,731,060 km (0.088 R)
- M89: 66,863,815 km (0.118 R)
- M90: 67,899,033 km (0.071 R)
- M91: 68,106,675 km (0.071 R)
- M92: 69,252,893 km (0.039 R)
Kuiper Belt
Range: 30 - 45 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 429 - 19,589 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.