G4V Star System Generated (Seed: 1767366985)
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 (9 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.87 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.03
Radius: 1.01
Gravity: 1.01 G
Time & Orbit
Eccentricity (e): 0.014
Orbit Range: 0.86 AU - 0.88 AU
Year: 296 Days
Day: 33.6 Hours
Environment
Temp: 116 °C
Axial Tilt: 17.2 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (1)
Outer Limit: 45,408,339 km
- M1: 48,171 km (0.086 R)
Planet 2 - Terrestrial
Semi-Major Axis: 1.15 AU
Status: HZ
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.19
Radius: 1.37
Gravity: 1.17 G
Time & Orbit
Eccentricity (e): 0.024
Orbit Range: 1.12 AU - 1.18 AU
Year: 450 Days
Day: 37.3 Hours
Environment
Temp: 11 °C
Axial Tilt: 27.8 °
Atmosphere: Nâ‚‚, Oâ‚‚
Biome: Arid/Tundra
Satellites (1)
Outer Limit: 45,408,339 km
- M1: 421,567 km (0.095 R)
Planet 3 - Terrestrial
Semi-Major Axis: 2.27 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.14
Radius: 0.46
Gravity: 0.66 G
Time & Orbit
Eccentricity (e): 0.008
Orbit Range: 2.25 AU - 2.29 AU
Year: 1249 Days
Day: 47.6 Hours
Environment
Temp: -78 °C
Axial Tilt: 3.3 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 4 - Terrestrial
Semi-Major Axis: 2.72 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.43
Radius: 1.81
Gravity: 1.35 G
Time & Orbit
Eccentricity (e): 0.063
Orbit Range: 2.55 AU - 2.89 AU
Year: 1638 Days
Day: 26.9 Hours
Environment
Temp: -95 °C
Axial Tilt: 34.3 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 45,408,339 km
- M1: 209,138 km (0.072 R)
Planet 5 - Gas Giant
Semi-Major Axis: 5.54 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 145.1
Radius: 14.9
Gravity: 0.65 G
Time & Orbit
Eccentricity (e): 0.172
Orbit Range: 4.59 AU - 6.49 AU
Year: 4763 Days
Day: 6.3 Hours
Environment
Temp: -151 °C
Axial Tilt: 31.4 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (40)
Outer Limit: 45,408,339 km
- M1: 223,499 km (0.09 R)
- M2: 366,664 km (0.111 R)
- M3: 690,095 km (0.066 R)
- M4: 910,901 km (0.03 R)
- M5: 1,069,176 km (0.088 R)
- M6: 1,176,886 km (0.109 R)
- M7: 1,361,939 km (0.062 R)
- M8: 1,479,972 km (0.086 R)
- M9: 2,327,444 km (0.12 R)
- M10: 2,725,972 km (0.114 R)
- M11: 3,218,748 km (0.061 R)
- M12: 3,468,427 km (0.079 R)
- M13: 3,785,873 km (0.087 R)
- M14: 4,034,056 km (0.081 R)
- M15: 5,114,602 km (0.088 R)
- M16: 5,217,226 km (0.1 R)
- M17: 6,080,705 km (0.11 R)
- M18: 6,207,713 km (0.044 R)
- M19: 7,026,612 km (0.057 R)
- M20: 7,141,054 km (0.108 R)
- M21: 7,585,061 km (0.072 R)
- M22: 7,761,437 km (0.054 R)
- M23: 8,399,172 km (0.081 R)
- M24: 8,991,879 km (0.105 R)
- M25: 9,429,453 km (0.114 R)
- M26: 9,682,722 km (0.078 R)
- M27: 10,152,908 km (0.098 R)
- M28: 10,477,835 km (0.099 R)
- M29: 11,249,311 km (0.089 R)
- M30: 11,495,549 km (0.08 R)
- M31: 12,084,815 km (0.093 R)
- M32: 13,104,474 km (0.114 R)
- M33: 13,505,845 km (0.115 R)
- M34: 13,767,642 km (0.083 R)
- M35: 13,887,320 km (0.083 R)
- M36: 15,523,173 km (0.114 R)
- M37: 15,847,650 km (0.043 R)
- M38: 16,174,372 km (0.085 R)
- M39: 16,275,351 km (0.097 R)
- M40: 16,808,966 km (0.1 R)
Planet 6 - Gas Giant
Semi-Major Axis: 7.87 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 154.9
Radius: 10.5
Gravity: 1.4 G
Time & Orbit
Eccentricity (e): 0.083
Orbit Range: 7.22 AU - 8.52 AU
Year: 8064 Days
Day: 10.5 Hours
Environment
Temp: -161 °C
Axial Tilt: 21.2 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (80)
Outer Limit: 45,408,339 km
- M1: 145,260 km (0.061 R)
- M2: 420,520 km (0.107 R)
- M3: 700,118 km (0.074 R)
- M4: 844,480 km (0.058 R)
- M5: 974,780 km (0.12 R)
- M6: 1,061,397 km (0.052 R)
- M7: 1,163,871 km (0.086 R)
- M8: 1,323,941 km (0.033 R)
- M9: 1,666,520 km (0.115 R)
- M10: 1,786,947 km (0.089 R)
- M11: 2,068,789 km (0.065 R)
- M12: 2,149,572 km (0.107 R)
- M13: 2,364,993 km (0.114 R)
- M14: 2,432,611 km (0.106 R)
- M15: 2,834,730 km (0.026 R)
- M16: 3,448,231 km (0.05 R)
- M17: 3,780,189 km (0.085 R)
- M18: 4,122,469 km (0.097 R)
- M19: 4,287,026 km (0.044 R)
- M20: 4,601,631 km (0.098 R)
- M21: 5,032,622 km (0.057 R)
- M22: 5,319,999 km (0.081 R)
- M23: 5,521,957 km (0.117 R)
- M24: 5,589,874 km (0.064 R)
- M25: 5,703,718 km (0.088 R)
- M26: 5,933,650 km (0.03 R)
- M27: 6,049,738 km (0.032 R)
- M28: 6,213,697 km (0.056 R)
- M29: 6,593,825 km (0.094 R)
- M30: 6,981,433 km (0.112 R)
- M31: 7,302,022 km (0.088 R)
- M32: 7,576,983 km (0.038 R)
- M33: 8,188,838 km (0.103 R)
- M34: 8,474,719 km (0.033 R)
- M35: 8,579,438 km (0.112 R)
- M36: 9,082,835 km (0.119 R)
- M37: 9,297,657 km (0.033 R)
- M38: 9,924,772 km (0.097 R)
- M39: 10,201,677 km (0.069 R)
- M40: 10,313,128 km (0.071 R)
- M41: 10,763,118 km (0.112 R)
- M42: 11,047,653 km (0.119 R)
- M43: 11,682,397 km (0.044 R)
- M44: 12,121,915 km (0.078 R)
- M45: 12,866,614 km (0.082 R)
- M46: 13,168,652 km (0.114 R)
- M47: 14,682,283 km (0.057 R)
- M48: 15,188,373 km (0.071 R)
- M49: 15,283,966 km (0.069 R)
- M50: 15,926,040 km (0.095 R)
- M51: 16,250,368 km (0.088 R)
- M52: 16,348,055 km (0.089 R)
- M53: 16,938,518 km (0.076 R)
- M54: 17,203,157 km (0.117 R)
- M55: 17,302,789 km (0.106 R)
- M56: 17,402,571 km (0.088 R)
- M57: 17,870,962 km (0.073 R)
- M58: 18,208,006 km (0.112 R)
- M59: 18,343,392 km (0.045 R)
- M60: 18,513,185 km (0.076 R)
- M61: 19,231,704 km (0.093 R)
- M62: 19,300,668 km (0.099 R)
- M63: 19,611,832 km (0.069 R)
- M64: 19,785,366 km (0.048 R)
- M65: 20,204,090 km (0.114 R)
- M66: 20,660,962 km (0.075 R)
- M67: 20,837,487 km (0.058 R)
- M68: 21,692,290 km (0.107 R)
- M69: 22,015,870 km (0.114 R)
- M70: 22,631,315 km (0.115 R)
- M71: 23,032,537 km (0.061 R)
- M72: 23,178,993 km (0.065 R)
- M73: 23,252,446 km (0.064 R)
- M74: 23,325,898 km (0.071 R)
- M75: 23,399,351 km (0.115 R)
- M76: 23,472,953 km (0.115 R)
- M77: 23,731,159 km (0.106 R)
- M78: 23,990,263 km (0.086 R)
- M79: 24,773,407 km (0.094 R)
- M80: 24,885,905 km (0.04 R)
Planet 7 - Gas Giant
Semi-Major Axis: 9.6 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 755.8
Radius: 11.9
Gravity: 5.34 G
Time & Orbit
Eccentricity (e): 0.165
Orbit Range: 8.02 AU - 11.18 AU
Year: 10864 Days
Day: 6.7 Hours
Environment
Temp: -175 °C
Axial Tilt: 7.4 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (80)
Outer Limit: 45,408,339 km
- M1: 200,162 km (0.112 R)
- M2: 366,814 km (0.028 R)
- M3: 460,911 km (0.11 R)
- M4: 646,263 km (0.106 R)
- M5: 749,186 km (0.115 R)
- M6: 1,012,927 km (0.085 R)
- M7: 1,114,654 km (0.068 R)
- M8: 1,848,282 km (0.081 R)
- M9: 2,000,572 km (0.025 R)
- M10: 2,210,159 km (0.097 R)
- M11: 2,427,076 km (0.117 R)
- M12: 2,594,476 km (0.066 R)
- M13: 2,765,915 km (0.094 R)
- M14: 2,852,981 km (0.047 R)
- M15: 3,150,082 km (0.088 R)
- M16: 3,426,090 km (0.066 R)
- M17: 3,742,191 km (0.083 R)
- M18: 4,851,609 km (0.11 R)
- M19: 5,028,284 km (0.11 R)
- M20: 6,869,235 km (0.116 R)
- M21: 7,107,844 km (0.098 R)
- M22: 7,430,227 km (0.114 R)
- M23: 7,634,279 km (0.08 R)
- M24: 7,798,836 km (0.108 R)
- M25: 8,173,280 km (0.05 R)
- M26: 9,113,502 km (0.086 R)
- M27: 9,332,065 km (0.05 R)
- M28: 10,314,025 km (0.049 R)
- M29: 10,725,120 km (0.032 R)
- M30: 11,048,700 km (0.115 R)
- M31: 12,134,332 km (0.107 R)
- M32: 12,326,715 km (0.059 R)
- M33: 12,958,616 km (0.109 R)
- M34: 16,698,862 km (0.109 R)
- M35: 17,073,904 km (0.061 R)
- M36: 17,506,092 km (0.119 R)
- M37: 18,161,032 km (0.096 R)
- M38: 19,046,950 km (0.118 R)
- M39: 19,382,648 km (0.053 R)
- M40: 19,494,996 km (0.074 R)
- M41: 20,230,718 km (0.063 R)
- M42: 21,729,390 km (0.064 R)
- M43: 21,904,569 km (0.091 R)
- M44: 22,197,781 km (0.086 R)
- M45: 22,374,157 km (0.105 R)
- M46: 23,025,207 km (0.074 R)
- M47: 25,015,606 km (0.101 R)
- M48: 25,568,071 km (0.097 R)
- M49: 25,814,908 km (0.114 R)
- M50: 26,809,883 km (0.098 R)
- M51: 27,881,004 km (0.107 R)
- M52: 28,645,449 km (0.099 R)
- M53: 28,901,710 km (0.051 R)
- M54: 30,390,508 km (0.066 R)
- M55: 31,243,067 km (0.114 R)
- M56: 31,970,411 km (0.07 R)
- M57: 32,169,825 km (0.116 R)
- M58: 34,322,090 km (0.118 R)
- M59: 34,867,524 km (0.098 R)
- M60: 35,209,804 km (0.082 R)
- M61: 35,553,131 km (0.087 R)
- M62: 36,035,733 km (0.094 R)
- M63: 37,707,041 km (0.063 R)
- M64: 38,481,359 km (0.09 R)
- M65: 38,835,158 km (0.096 R)
- M66: 39,047,887 km (0.095 R)
- M67: 39,759,823 km (0.096 R)
- M68: 40,045,854 km (0.113 R)
- M69: 41,631,143 km (0.106 R)
- M70: 45,011,456 km (0.098 R)
- M71: 46,358,136 km (0.111 R)
- M72: 47,490,442 km (0.097 R)
- M73: 48,326,545 km (0.068 R)
- M74: 48,402,690 km (0.039 R)
- M75: 48,784,614 km (0.063 R)
- M76: 48,861,058 km (0.034 R)
- M77: 49,551,303 km (0.073 R)
- M78: 49,628,196 km (0.119 R)
- M79: 50,167,646 km (0.098 R)
- M80: 51,485,603 km (0.08 R)
Planet 8 - Ice Giant
Semi-Major Axis: 13.13 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 834.3
Radius: 5.4
Gravity: 28.61 G
Time & Orbit
Eccentricity (e): 0.001
Orbit Range: 13.12 AU - 13.14 AU
Year: 17378 Days
Day: 24.9 Hours
Environment
Temp: -189 °C
Axial Tilt: 1.6 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (93)
Outer Limit: 45,408,339 km
- M1: 69,563 km (0.106 R)
- M2: 276,307 km (0.112 R)
- M3: 490,382 km (0.109 R)
- M4: 749,485 km (0.036 R)
- M5: 994,826 km (0.107 R)
- M6: 1,677,441 km (0.097 R)
- M7: 1,866,832 km (0.082 R)
- M8: 1,931,458 km (0.054 R)
- M9: 2,163,634 km (0.12 R)
- M10: 3,178,506 km (0.12 R)
- M11: 3,294,893 km (0.078 R)
- M12: 4,276,106 km (0.044 R)
- M13: 5,112,058 km (0.063 R)
- M14: 5,432,497 km (0.104 R)
- M15: 5,618,597 km (0.103 R)
- M16: 5,759,518 km (0.054 R)
- M17: 6,580,062 km (0.075 R)
- M18: 6,978,741 km (0.112 R)
- M19: 7,747,225 km (0.091 R)
- M20: 8,062,128 km (0.066 R)
- M21: 8,867,414 km (0.115 R)
- M22: 9,642,032 km (0.039 R)
- M23: 10,438,191 km (0.088 R)
- M24: 11,314,237 km (0.069 R)
- M25: 12,092,594 km (0.088 R)
- M26: 12,702,954 km (0.082 R)
- M27: 12,764,438 km (0.101 R)
- M28: 13,011,873 km (0.077 R)
- M29: 14,400,291 km (0.078 R)
- M30: 14,593,272 km (0.094 R)
- M31: 14,981,778 km (0.093 R)
- M32: 16,569,460 km (0.094 R)
- M33: 17,588,670 km (0.113 R)
- M34: 18,071,273 km (0.068 R)
- M35: 20,404,102 km (0.059 R)
- M36: 22,307,586 km (0.119 R)
- M37: 22,381,936 km (0.096 R)
- M38: 22,530,935 km (0.036 R)
- M39: 24,420,207 km (0.066 R)
- M40: 24,650,288 km (0.108 R)
- M41: 26,911,460 km (0.091 R)
- M42: 27,069,735 km (0.112 R)
- M43: 27,307,895 km (0.12 R)
- M44: 28,106,747 km (0.106 R)
- M45: 28,347,899 km (0.115 R)
- M46: 30,962,421 km (0.104 R)
- M47: 32,046,407 km (0.101 R)
- M48: 32,130,331 km (0.117 R)
- M49: 36,943,793 km (0.084 R)
- M50: 37,031,756 km (0.098 R)
- M51: 37,561,033 km (0.081 R)
- M52: 40,425,982 km (0.069 R)
- M53: 42,252,123 km (0.096 R)
- M54: 42,528,281 km (0.12 R)
- M55: 42,712,735 km (0.119 R)
- M56: 45,417,465 km (0.118 R)
- M57: 46,457,768 km (0.06 R)
- M58: 46,552,763 km (0.097 R)
- M59: 46,742,902 km (0.043 R)
- M60: 48,273,139 km (0.106 R)
- M61: 48,465,671 km (0.079 R)
- M62: 50,306,473 km (0.116 R)
- M63: 51,088,421 km (0.102 R)
- M64: 51,186,407 km (0.079 R)
- M65: 51,874,408 km (0.071 R)
- M66: 52,763,319 km (0.091 R)
- M67: 52,961,536 km (0.113 R)
- M68: 53,856,580 km (0.068 R)
- M69: 53,956,362 km (0.074 R)
- M70: 54,456,168 km (0.059 R)
- M71: 54,756,710 km (0.092 R)
- M72: 54,957,471 km (0.116 R)
- M73: 55,560,948 km (0.026 R)
- M74: 55,964,563 km (0.114 R)
- M75: 56,369,076 km (0.046 R)
- M76: 57,997,150 km (0.11 R)
- M77: 58,201,650 km (0.111 R)
- M78: 59,434,187 km (0.12 R)
- M79: 60,157,044 km (0.099 R)
- M80: 60,467,759 km (0.026 R)
- M81: 60,571,579 km (0.113 R)
- M82: 62,448,135 km (0.092 R)
- M83: 62,657,722 km (0.052 R)
- M84: 62,867,608 km (0.082 R)
- M85: 63,498,761 km (0.099 R)
- M86: 64,767,501 km (0.108 R)
- M87: 65,511,301 km (0.11 R)
- M88: 68,083,188 km (0.101 R)
- M89: 72,222,262 km (0.105 R)
- M90: 72,772,931 km (0.047 R)
- M91: 72,883,185 km (0.043 R)
- M92: 73,324,948 km (0.104 R)
- M93: 73,656,905 km (0.079 R)
Planet 9 - Ice Giant
Semi-Major Axis: 16.94 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 89.8
Radius: 5.2
Gravity: 3.32 G
Time & Orbit
Eccentricity (e): 0.115
Orbit Range: 14.99 AU - 18.89 AU
Year: 25466 Days
Day: 16 Hours
Environment
Temp: -193 °C
Axial Tilt: 6.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (92)
Outer Limit: 45,408,339 km
- M1: 541,544 km (0.112 R)
- M2: 714,479 km (0.078 R)
- M3: 1,090,718 km (0.073 R)
- M4: 1,371,513 km (0.103 R)
- M5: 1,674,000 km (0.101 R)
- M6: 1,787,096 km (0.105 R)
- M7: 2,594,177 km (0.1 R)
- M8: 3,159,208 km (0.1 R)
- M9: 3,556,390 km (0.091 R)
- M10: 3,643,456 km (0.113 R)
- M11: 3,999,200 km (0.093 R)
- M12: 4,553,610 km (0.086 R)
- M13: 4,871,804 km (0.075 R)
- M14: 6,426,276 km (0.097 R)
- M15: 6,746,864 km (0.116 R)
- M16: 6,818,970 km (0.12 R)
- M17: 7,366,947 km (0.109 R)
- M18: 8,004,832 km (0.084 R)
- M19: 8,042,980 km (0.062 R)
- M20: 8,234,316 km (0.049 R)
- M21: 8,388,401 km (0.107 R)
- M22: 8,543,534 km (0.033 R)
- M23: 8,738,760 km (0.074 R)
- M24: 8,817,298 km (0.066 R)
- M25: 8,974,975 km (0.117 R)
- M26: 9,493,930 km (0.063 R)
- M27: 10,228,455 km (0.104 R)
- M28: 10,519,124 km (0.118 R)
- M29: 10,686,374 km (0.094 R)
- M30: 10,728,262 km (0.112 R)
- M31: 11,492,856 km (0.091 R)
- M32: 12,939,468 km (0.107 R)
- M33: 13,298,802 km (0.092 R)
- M34: 13,615,800 km (0.107 R)
- M35: 13,798,160 km (0.076 R)
- M36: 13,935,490 km (0.104 R)
- M37: 14,257,425 km (0.075 R)
- M38: 14,628,577 km (0.115 R)
- M39: 16,144,153 km (0.041 R)
- M40: 16,192,324 km (0.098 R)
- M41: 16,385,455 km (0.1 R)
- M42: 16,530,864 km (0.12 R)
- M43: 16,774,110 km (0.093 R)
- M44: 16,969,485 km (0.108 R)
- M45: 17,018,553 km (0.12 R)
- M46: 17,609,913 km (0.032 R)
- M47: 19,066,697 km (0.116 R)
- M48: 19,117,561 km (0.116 R)
- M49: 19,475,249 km (0.106 R)
- M50: 19,629,335 km (0.087 R)
- M51: 21,085,820 km (0.104 R)
- M52: 21,880,334 km (0.09 R)
- M53: 21,933,741 km (0.059 R)
- M54: 22,040,404 km (0.057 R)
- M55: 23,117,509 km (0.097 R)
- M56: 23,171,962 km (0.076 R)
- M57: 23,389,477 km (0.085 R)
- M58: 24,046,511 km (0.111 R)
- M59: 24,654,178 km (0.083 R)
- M60: 24,876,331 km (0.113 R)
- M61: 25,378,680 km (0.081 R)
- M62: 25,828,072 km (0.087 R)
- M63: 25,884,471 km (0.104 R)
- M64: 26,280,008 km (0.107 R)
- M65: 26,791,632 km (0.078 R)
- M66: 26,905,775 km (0.091 R)
- M67: 27,767,010 km (0.116 R)
- M68: 28,229,866 km (0.033 R)
- M69: 28,637,072 km (0.046 R)
- M70: 29,046,222 km (0.085 R)
- M71: 30,523,202 km (0.104 R)
- M72: 31,001,017 km (0.104 R)
- M73: 31,963,979 km (0.05 R)
- M74: 32,085,003 km (0.109 R)
- M75: 32,997,850 km (0.101 R)
- M76: 34,352,009 km (0.113 R)
- M77: 34,476,026 km (0.062 R)
- M78: 34,848,974 km (0.094 R)
- M79: 34,973,589 km (0.098 R)
- M80: 35,598,758 km (0.104 R)
- M81: 36,290,798 km (0.078 R)
- M82: 36,987,176 km (0.103 R)
- M83: 37,496,407 km (0.04 R)
- M84: 37,751,920 km (0.113 R)
- M85: 38,328,919 km (0.103 R)
- M86: 38,844,284 km (0.103 R)
- M87: 41,984,194 km (0.05 R)
- M88: 42,249,431 km (0.092 R)
- M89: 42,982,011 km (0.075 R)
- M90: 44,324,503 km (0.103 R)
- M91: 44,391,971 km (0.106 R)
- M92: 44,662,295 km (0.025 R)
Kuiper Belt
Range: 30 - 56 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 434 - 11,164 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.