G4V Star System Generated (Seed: 1766711324)
Star Details
Spectral Class: G6V
Temperature: 5,480 K
Mass: 0.97 sol
Luminosity: 0.9 lux
Habitable Zone (HZ)
Inner Boundary: 0.9 AU
Outer Boundary: 1.3 AU
Physical Limits
Snow Line: 4.55 AU
Max System Radius: 19.7 AU
Planetary System (10 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.61 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.81
Radius: 0.92
Gravity: 0.96 G
Time & Orbit
Eccentricity (e): 0.092
Orbit Range: 0.55 AU - 0.67 AU
Year: 177 Days
Day: 21.1 Hours
Environment
Temp: 215 °C
Axial Tilt: 28.3 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 2 - Terrestrial
Semi-Major Axis: 0.63 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.15
Radius: 1.36
Gravity: 1.16 G
Time & Orbit
Eccentricity (e): 0.009
Orbit Range: 0.62 AU - 0.64 AU
Year: 185 Days
Day: 35.7 Hours
Environment
Temp: 153 °C
Axial Tilt: 23.8 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (1)
Outer Limit: 47,014,111 km
- M1: 338,241 km (0.089 R)
Planet 3 - Terrestrial
Semi-Major Axis: 1.45 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.74
Radius: 1.5
Gravity: 1.22 G
Time & Orbit
Eccentricity (e): 0.096
Orbit Range: 1.31 AU - 1.59 AU
Year: 648 Days
Day: 27.5 Hours
Environment
Temp: -38 °C
Axial Tilt: 35.7 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 47,014,111 km
- M1: 175,927 km (0.039 R)
Planet 4 - Terrestrial
Semi-Major Axis: 1.51 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.03
Radius: 1.75
Gravity: 1.32 G
Time & Orbit
Eccentricity (e): 0.201
Orbit Range: 1.21 AU - 1.81 AU
Year: 688 Days
Day: 28.1 Hours
Environment
Temp: -49 °C
Axial Tilt: 34.4 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 47,014,111 km
- M1: 1,262,756 km (0.074 R)
Planet 5 - Terrestrial
Semi-Major Axis: 2.52 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.94
Radius: 1.54
Gravity: 1.24 G
Time & Orbit
Eccentricity (e): 0.088
Orbit Range: 2.3 AU - 2.74 AU
Year: 1484 Days
Day: 41.7 Hours
Environment
Temp: -93 °C
Axial Tilt: 153.1 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 6 - Gas Giant
Semi-Major Axis: 5.17 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 953.6
Radius: 14.8
Gravity: 4.35 G
Time & Orbit
Eccentricity (e): 0.138
Orbit Range: 4.46 AU - 5.88 AU
Year: 4360 Days
Day: 12.2 Hours
Environment
Temp: -153 °C
Axial Tilt: 1.6 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (74)
Outer Limit: 47,014,111 km
- M1: 229,334 km (0.094 R)
- M2: 392,994 km (0.086 R)
- M3: 702,661 km (0.111 R)
- M4: 1,079,648 km (0.105 R)
- M5: 1,209,948 km (0.106 R)
- M6: 1,584,840 km (0.108 R)
- M7: 1,907,971 km (0.091 R)
- M8: 2,271,494 km (0.052 R)
- M9: 2,385,039 km (0.102 R)
- M10: 2,578,618 km (0.074 R)
- M11: 3,148,736 km (0.102 R)
- M12: 3,254,651 km (0.063 R)
- M13: 3,646,448 km (0.047 R)
- M14: 4,076,542 km (0.083 R)
- M15: 4,619,283 km (0.102 R)
- M16: 4,887,063 km (0.07 R)
- M17: 5,134,947 km (0.116 R)
- M18: 5,851,371 km (0.083 R)
- M19: 6,901,399 km (0.063 R)
- M20: 7,124,150 km (0.098 R)
- M21: 7,377,419 km (0.069 R)
- M22: 7,490,964 km (0.073 R)
- M23: 8,688,794 km (0.067 R)
- M24: 8,869,059 km (0.103 R)
- M25: 9,172,444 km (0.056 R)
- M26: 9,479,119 km (0.089 R)
- M27: 9,820,502 km (0.031 R)
- M28: 10,039,962 km (0.099 R)
- M29: 10,739,930 km (0.06 R)
- M30: 11,063,361 km (0.062 R)
- M31: 11,886,149 km (0.081 R)
- M32: 12,321,778 km (0.082 R)
- M33: 12,626,509 km (0.091 R)
- M34: 12,899,376 km (0.087 R)
- M35: 13,278,008 km (0.11 R)
- M36: 13,765,098 km (0.079 R)
- M37: 13,870,116 km (0.073 R)
- M38: 15,080,513 km (0.085 R)
- M39: 15,225,174 km (0.097 R)
- M40: 15,406,636 km (0.117 R)
- M41: 15,918,410 km (0.099 R)
- M42: 16,176,467 km (0.039 R)
- M43: 16,287,468 km (0.07 R)
- M44: 16,510,219 km (0.11 R)
- M45: 16,921,314 km (0.094 R)
- M46: 17,411,547 km (0.113 R)
- M47: 17,715,679 km (0.096 R)
- M48: 18,251,838 km (0.111 R)
- M49: 18,444,669 km (0.1 R)
- M50: 18,560,757 km (0.102 R)
- M51: 18,793,532 km (0.054 R)
- M52: 19,458,345 km (0.075 R)
- M53: 19,773,847 km (0.092 R)
- M54: 20,051,351 km (0.098 R)
- M55: 20,330,201 km (0.082 R)
- M56: 20,450,029 km (0.111 R)
- M57: 20,690,433 km (0.091 R)
- M58: 21,012,517 km (0.068 R)
- M59: 22,029,782 km (0.086 R)
- M60: 23,146,381 km (0.101 R)
- M61: 23,271,594 km (0.095 R)
- M62: 23,438,994 km (0.033 R)
- M63: 23,732,655 km (0.095 R)
- M64: 24,239,044 km (0.091 R)
- M65: 24,451,174 km (0.106 R)
- M66: 24,663,902 km (0.117 R)
- M67: 24,791,808 km (0.119 R)
- M68: 25,048,219 km (0.12 R)
- M69: 25,779,752 km (0.059 R)
- M70: 26,213,287 km (0.083 R)
- M71: 26,561,850 km (0.091 R)
- M72: 27,263,763 km (0.045 R)
- M73: 28,999,996 km (0.075 R)
- M74: 29,134,933 km (0.107 R)
Planet 7 - Gas Giant
Semi-Major Axis: 7.78 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 896.7
Radius: 10
Gravity: 8.97 G
Time & Orbit
Eccentricity (e): 0.161
Orbit Range: 6.53 AU - 9.03 AU
Year: 8048 Days
Day: 6.1 Hours
Environment
Temp: -160 °C
Axial Tilt: 32.2 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (85)
Outer Limit: 47,014,111 km
- M1: 131,796 km (0.048 R)
- M2: 252,372 km (0.114 R)
- M3: 446,400 km (0.105 R)
- M4: 541,993 km (0.099 R)
- M5: 676,332 km (0.065 R)
- M6: 772,673 km (0.031 R)
- M7: 1,016,667 km (0.109 R)
- M8: 1,641,687 km (0.112 R)
- M9: 1,707,809 km (0.068 R)
- M10: 1,820,157 km (0.096 R)
- M11: 1,934,899 km (0.06 R)
- M12: 3,129,139 km (0.09 R)
- M13: 3,579,428 km (0.029 R)
- M14: 4,697,672 km (0.102 R)
- M15: 4,888,709 km (0.117 R)
- M16: 5,344,234 km (0.081 R)
- M17: 6,191,706 km (0.037 R)
- M18: 6,401,293 km (0.098 R)
- M19: 6,971,710 km (0.113 R)
- M20: 7,189,823 km (0.111 R)
- M21: 7,707,581 km (0.106 R)
- M22: 7,820,079 km (0.054 R)
- M23: 8,199,160 km (0.094 R)
- M24: 8,275,754 km (0.057 R)
- M25: 9,014,618 km (0.1 R)
- M26: 9,452,192 km (0.091 R)
- M27: 9,572,768 km (0.092 R)
- M28: 9,855,957 km (0.111 R)
- M29: 10,555,327 km (0.076 R)
- M30: 10,680,390 km (0.091 R)
- M31: 10,847,940 km (0.116 R)
- M32: 11,398,610 km (0.116 R)
- M33: 11,526,965 km (0.073 R)
- M34: 11,828,255 km (0.117 R)
- M35: 12,175,920 km (0.112 R)
- M36: 14,009,841 km (0.102 R)
- M37: 14,655,505 km (0.101 R)
- M38: 15,075,875 km (0.033 R)
- M39: 15,405,439 km (0.106 R)
- M40: 16,071,898 km (0.082 R)
- M41: 16,167,939 km (0.035 R)
- M42: 16,650,542 km (0.116 R)
- M43: 18,277,120 km (0.077 R)
- M44: 18,477,581 km (0.083 R)
- M45: 18,729,354 km (0.081 R)
- M46: 19,033,038 km (0.107 R)
- M47: 19,542,718 km (0.106 R)
- M48: 20,263,780 km (0.065 R)
- M49: 20,679,662 km (0.074 R)
- M50: 21,519,953 km (0.118 R)
- M51: 22,963,273 km (0.082 R)
- M52: 24,107,398 km (0.12 R)
- M53: 24,991,521 km (0.098 R)
- M54: 25,437,622 km (0.078 R)
- M55: 25,661,570 km (0.098 R)
- M56: 27,247,906 km (0.111 R)
- M57: 27,995,297 km (0.071 R)
- M58: 29,040,986 km (0.111 R)
- M59: 29,216,614 km (0.045 R)
- M60: 29,568,767 km (0.054 R)
- M61: 29,745,293 km (0.115 R)
- M62: 30,040,449 km (0.063 R)
- M63: 30,218,022 km (0.1 R)
- M64: 30,991,443 km (0.107 R)
- M65: 31,290,639 km (0.087 R)
- M66: 31,952,160 km (0.065 R)
- M67: 32,073,035 km (0.102 R)
- M68: 32,679,206 km (0.052 R)
- M69: 32,861,865 km (0.097 R)
- M70: 34,830,723 km (0.06 R)
- M71: 34,955,038 km (0.097 R)
- M72: 35,328,884 km (0.064 R)
- M73: 35,829,438 km (0.107 R)
- M74: 37,218,005 km (0.086 R)
- M75: 37,791,115 km (0.114 R)
- M76: 38,817,207 km (0.055 R)
- M77: 39,592,722 km (0.082 R)
- M78: 39,787,349 km (0.074 R)
- M79: 39,852,424 km (0.047 R)
- M80: 40,308,099 km (0.064 R)
- M81: 40,765,569 km (0.112 R)
- M82: 41,159,161 km (0.097 R)
- M83: 41,685,746 km (0.113 R)
- M84: 42,945,510 km (0.083 R)
- M85: 45,162,999 km (0.115 R)
Planet 8 - Gas Giant
Semi-Major Axis: 7.98 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 43.7
Radius: 9.9
Gravity: 0.45 G
Time & Orbit
Eccentricity (e): 0.238
Orbit Range: 6.08 AU - 9.88 AU
Year: 8360 Days
Day: 10 Hours
Environment
Temp: -167 °C
Axial Tilt: 77.8 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (46)
Outer Limit: 47,014,111 km
- M1: 127,457 km (0.117 R)
- M2: 253,120 km (0.1 R)
- M3: 402,717 km (0.109 R)
- M4: 519,404 km (0.072 R)
- M5: 689,048 km (0.086 R)
- M6: 764,146 km (0.075 R)
- M7: 1,093,560 km (0.057 R)
- M8: 1,233,584 km (0.111 R)
- M9: 1,337,255 km (0.113 R)
- M10: 1,400,984 km (0.104 R)
- M11: 1,643,632 km (0.058 R)
- M12: 1,758,523 km (0.062 R)
- M13: 2,107,086 km (0.082 R)
- M14: 2,881,853 km (0.077 R)
- M15: 2,951,416 km (0.119 R)
- M16: 3,021,428 km (0.073 R)
- M17: 3,206,331 km (0.1 R)
- M18: 3,468,427 km (0.112 R)
- M19: 3,707,334 km (0.119 R)
- M20: 4,138,326 km (0.105 R)
- M21: 4,217,014 km (0.031 R)
- M22: 5,664,523 km (0.081 R)
- M23: 5,946,366 km (0.075 R)
- M24: 6,707,669 km (0.097 R)
- M25: 7,289,306 km (0.106 R)
- M26: 7,422,897 km (0.093 R)
- M27: 7,848,054 km (0.117 R)
- M28: 7,965,339 km (0.103 R)
- M29: 8,142,463 km (0.113 R)
- M30: 8,301,036 km (0.117 R)
- M31: 8,986,194 km (0.05 R)
- M32: 9,150,004 km (0.106 R)
- M33: 9,273,572 km (0.058 R)
- M34: 9,376,944 km (0.064 R)
- M35: 10,712,404 km (0.092 R)
- M36: 12,401,364 km (0.114 R)
- M37: 12,515,358 km (0.119 R)
- M38: 12,859,433 km (0.098 R)
- M39: 13,183,462 km (0.088 R)
- M40: 13,253,175 km (0.11 R)
- M41: 14,171,556 km (0.085 R)
- M42: 14,626,333 km (0.118 R)
- M43: 15,501,331 km (0.119 R)
- M44: 15,821,321 km (0.077 R)
- M45: 15,945,039 km (0.068 R)
- M46: 16,418,067 km (0.098 R)
Planet 9 - Gas Giant
Semi-Major Axis: 8.81 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 423.5
Radius: 12.4
Gravity: 2.75 G
Time & Orbit
Eccentricity (e): 0.209
Orbit Range: 6.97 AU - 10.65 AU
Year: 9698 Days
Day: 13.2 Hours
Environment
Temp: -162 °C
Axial Tilt: 114.2 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (81)
Outer Limit: 47,014,111 km
- M1: 172,786 km (0.04 R)
- M2: 250,427 km (0.049 R)
- M3: 331,060 km (0.098 R)
- M4: 509,530 km (0.09 R)
- M5: 1,194,539 km (0.087 R)
- M6: 1,549,086 km (0.08 R)
- M7: 1,810,882 km (0.041 R)
- M8: 2,043,806 km (0.098 R)
- M9: 2,377,409 km (0.07 R)
- M10: 2,752,750 km (0.08 R)
- M11: 3,480,843 km (0.065 R)
- M12: 4,492,873 km (0.107 R)
- M13: 4,636,337 km (0.038 R)
- M14: 4,928,053 km (0.082 R)
- M15: 5,135,844 km (0.084 R)
- M16: 5,590,772 km (0.102 R)
- M17: 5,838,805 km (0.12 R)
- M18: 6,249,601 km (0.051 R)
- M19: 6,410,119 km (0.106 R)
- M20: 7,812,300 km (0.067 R)
- M21: 7,950,678 km (0.102 R)
- M22: 8,089,954 km (0.066 R)
- M23: 8,834,203 km (0.1 R)
- M24: 9,232,881 km (0.111 R)
- M25: 9,823,195 km (0.073 R)
- M26: 10,349,779 km (0.12 R)
- M27: 10,502,070 km (0.098 R)
- M28: 11,001,727 km (0.074 R)
- M29: 11,079,218 km (0.114 R)
- M30: 11,157,009 km (0.118 R)
- M31: 11,352,234 km (0.099 R)
- M32: 11,509,163 km (0.065 R)
- M33: 12,184,447 km (0.104 R)
- M34: 12,831,757 km (0.113 R)
- M35: 13,118,536 km (0.028 R)
- M36: 13,200,815 km (0.037 R)
- M37: 13,823,591 km (0.111 R)
- M38: 14,075,514 km (0.081 R)
- M39: 14,244,260 km (0.118 R)
- M40: 15,141,100 km (0.078 R)
- M41: 15,400,802 km (0.096 R)
- M42: 15,968,376 km (0.113 R)
- M43: 17,621,283 km (0.115 R)
- M44: 18,123,184 km (0.118 R)
- M45: 18,861,449 km (0.109 R)
- M46: 19,845,654 km (0.115 R)
- M47: 20,034,895 km (0.094 R)
- M48: 20,177,312 km (0.098 R)
- M49: 20,415,472 km (0.099 R)
- M50: 20,942,505 km (0.094 R)
- M51: 21,038,846 km (0.08 R)
- M52: 21,328,617 km (0.117 R)
- M53: 21,619,735 km (0.114 R)
- M54: 22,255,226 km (0.114 R)
- M55: 22,353,512 km (0.095 R)
- M56: 22,797,668 km (0.119 R)
- M57: 22,996,035 km (0.077 R)
- M58: 23,095,368 km (0.09 R)
- M59: 23,544,311 km (0.083 R)
- M60: 23,644,542 km (0.111 R)
- M61: 23,744,772 km (0.051 R)
- M62: 25,164,157 km (0.11 R)
- M63: 25,420,418 km (0.103 R)
- M64: 25,780,799 km (0.091 R)
- M65: 26,246,498 km (0.108 R)
- M66: 26,767,397 km (0.091 R)
- M67: 26,871,966 km (0.093 R)
- M68: 26,976,685 km (0.087 R)
- M69: 27,766,262 km (0.107 R)
- M70: 29,800,494 km (0.066 R)
- M71: 30,071,715 km (0.044 R)
- M72: 30,289,380 km (0.105 R)
- M73: 30,945,217 km (0.064 R)
- M74: 31,274,931 km (0.097 R)
- M75: 32,215,453 km (0.1 R)
- M76: 34,351,112 km (0.084 R)
- M77: 34,977,927 km (0.109 R)
- M78: 35,723,523 km (0.095 R)
- M79: 37,113,736 km (0.104 R)
- M80: 38,698,875 km (0.076 R)
- M81: 39,410,512 km (0.105 R)
Planet 10 - Gas Giant
Semi-Major Axis: 9.11 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 621.6
Radius: 11.1
Gravity: 5.05 G
Time & Orbit
Eccentricity (e): 0.226
Orbit Range: 7.05 AU - 11.17 AU
Year: 10197 Days
Day: 9.6 Hours
Environment
Temp: -178 °C
Axial Tilt: 18 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (87)
Outer Limit: 47,014,111 km
- M1: 139,575 km (0.109 R)
- M2: 323,281 km (0.083 R)
- M3: 393,891 km (0.038 R)
- M4: 499,058 km (0.11 R)
- M5: 570,716 km (0.078 R)
- M6: 896,989 km (0.104 R)
- M7: 1,510,639 km (0.118 R)
- M8: 1,942,379 km (0.064 R)
- M9: 2,489,009 km (0.064 R)
- M10: 2,593,578 km (0.101 R)
- M11: 2,726,272 km (0.079 R)
- M12: 2,834,132 km (0.113 R)
- M13: 3,194,513 km (0.047 R)
- M14: 3,365,952 km (0.066 R)
- M15: 3,569,704 km (0.111 R)
- M16: 4,393,839 km (0.116 R)
- M17: 5,140,931 km (0.116 R)
- M18: 6,678,049 km (0.115 R)
- M19: 6,824,505 km (0.057 R)
- M20: 8,072,750 km (0.025 R)
- M21: 8,544,133 km (0.119 R)
- M22: 8,623,569 km (0.088 R)
- M23: 8,703,155 km (0.06 R)
- M24: 8,903,467 km (0.092 R)
- M25: 9,472,388 km (0.05 R)
- M26: 9,719,822 km (0.06 R)
- M27: 10,263,312 km (0.028 R)
- M28: 10,347,834 km (0.119 R)
- M29: 11,292,545 km (0.075 R)
- M30: 11,686,885 km (0.09 R)
- M31: 11,996,852 km (0.047 R)
- M32: 12,309,511 km (0.099 R)
- M33: 12,760,848 km (0.117 R)
- M34: 12,851,803 km (0.065 R)
- M35: 14,147,171 km (0.115 R)
- M36: 15,387,039 km (0.113 R)
- M37: 15,971,069 km (0.05 R)
- M38: 17,110,556 km (0.109 R)
- M39: 17,311,466 km (0.09 R)
- M40: 17,715,529 km (0.111 R)
- M41: 17,867,820 km (0.077 R)
- M42: 17,969,696 km (0.069 R)
- M43: 18,224,910 km (0.048 R)
- M44: 18,739,228 km (0.074 R)
- M45: 18,894,510 km (0.11 R)
- M46: 21,706,501 km (0.067 R)
- M47: 22,251,636 km (0.101 R)
- M48: 23,077,716 km (0.089 R)
- M49: 23,578,270 km (0.103 R)
- M50: 24,873,488 km (0.12 R)
- M51: 25,443,905 km (0.1 R)
- M52: 25,845,725 km (0.08 R)
- M53: 26,481,516 km (0.118 R)
- M54: 26,713,841 km (0.078 R)
- M55: 26,830,378 km (0.093 R)
- M56: 27,005,408 km (0.03 R)
- M57: 28,241,236 km (0.112 R)
- M58: 28,419,257 km (0.091 R)
- M59: 28,657,267 km (0.094 R)
- M60: 29,195,221 km (0.11 R)
- M61: 29,375,187 km (0.097 R)
- M62: 30,951,051 km (0.095 R)
- M63: 31,379,949 km (0.049 R)
- M64: 31,564,403 km (0.117 R)
- M65: 32,492,059 km (0.049 R)
- M66: 33,428,542 km (0.054 R)
- M67: 33,554,054 km (0.052 R)
- M68: 33,868,659 km (0.071 R)
- M69: 34,881,885 km (0.056 R)
- M70: 35,264,257 km (0.068 R)
- M71: 37,002,734 km (0.074 R)
- M72: 37,523,185 km (0.119 R)
- M73: 37,980,506 km (0.088 R)
- M74: 39,695,496 km (0.054 R)
- M75: 40,696,306 km (0.069 R)
- M76: 41,099,023 km (0.092 R)
- M77: 41,435,618 km (0.052 R)
- M78: 43,063,841 km (0.072 R)
- M79: 43,200,574 km (0.12 R)
- M80: 43,611,220 km (0.114 R)
- M81: 43,817,216 km (0.074 R)
- M82: 44,023,362 km (0.066 R)
- M83: 44,713,008 km (0.118 R)
- M84: 45,963,347 km (0.07 R)
- M85: 46,103,072 km (0.116 R)
- M86: 46,242,796 km (0.12 R)
- M87: 46,452,682 km (0.027 R)
Kuiper Belt
Range: 30 - 51 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 226 - 12,442 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.