G3V Star System Generated (Seed: 1768614943)
Star Details
Spectral Class: G9V
Temperature: 5,200 K
Mass: 0.9 sol
Luminosity: 0.69 lux
Habitable Zone (HZ)
Inner Boundary: 0.79 AU
Outer Boundary: 1.14 AU
Physical Limits
Snow Line: 3.99 AU
Max System Radius: 19 AU
Planetary System (10 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.55 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.12
Radius: 1.35
Gravity: 1.16 G
Time & Orbit
Eccentricity (e): 0.211
Orbit Range: 0.43 AU - 0.67 AU
Year: 157 Days
Day: 13.5 Hours
Environment
Temp: 155 °C
Axial Tilt: 10.9 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 2 - Terrestrial
Semi-Major Axis: 1.07 AU
Status: HZ
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 3.94
Radius: 1.73
Gravity: 1.32 G
Time & Orbit
Eccentricity (e): 0.154
Orbit Range: 0.91 AU - 1.23 AU
Year: 426 Days
Day: 20.6 Hours
Environment
Temp: -7 °C
Axial Tilt: 23.2 °
Atmosphere: Nâ‚‚, Oâ‚‚
Biome: Arid/Tundra
Planet 3 - Terrestrial
Semi-Major Axis: 1.67 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.72
Radius: 1.24
Gravity: 1.12 G
Time & Orbit
Eccentricity (e): 0.179
Orbit Range: 1.37 AU - 1.97 AU
Year: 831 Days
Day: 42.1 Hours
Environment
Temp: -61 °C
Axial Tilt: 0.3 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 34,984,863 km
- M1: 930,200 km (0.065 R)
Planet 4 - Terrestrial
Semi-Major Axis: 3.49 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.37
Radius: 0.67
Gravity: 0.82 G
Time & Orbit
Eccentricity (e): 0.062
Orbit Range: 3.27 AU - 3.71 AU
Year: 2510 Days
Day: 41.5 Hours
Environment
Temp: -122 °C
Axial Tilt: 18.2 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 5 - Gas Giant
Semi-Major Axis: 4.67 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 872.3
Radius: 14.3
Gravity: 4.27 G
Time & Orbit
Eccentricity (e): 0.063
Orbit Range: 4.38 AU - 4.96 AU
Year: 3885 Days
Day: 12.8 Hours
Environment
Temp: -154 °C
Axial Tilt: 177.6 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (72)
Outer Limit: 34,984,863 km
- M1: 187,596 km (0.047 R)
- M2: 414,386 km (0.116 R)
- M3: 542,143 km (0.118 R)
- M4: 665,262 km (0.063 R)
- M5: 858,991 km (0.101 R)
- M6: 957,426 km (0.105 R)
- M7: 1,086,380 km (0.106 R)
- M8: 1,277,865 km (0.106 R)
- M9: 1,541,157 km (0.089 R)
- M10: 1,726,958 km (0.059 R)
- M11: 1,953,449 km (0.09 R)
- M12: 2,053,680 km (0.061 R)
- M13: 2,562,911 km (0.104 R)
- M14: 2,822,912 km (0.116 R)
- M15: 3,052,844 km (0.114 R)
- M16: 3,170,278 km (0.114 R)
- M17: 3,738,152 km (0.116 R)
- M18: 3,885,057 km (0.048 R)
- M19: 4,163,309 km (0.082 R)
- M20: 4,626,763 km (0.112 R)
- M21: 4,830,515 km (0.116 R)
- M22: 4,944,958 km (0.087 R)
- M23: 5,083,635 km (0.114 R)
- M24: 5,991,694 km (0.114 R)
- M25: 6,515,137 km (0.082 R)
- M26: 6,667,427 km (0.112 R)
- M27: 7,001,480 km (0.102 R)
- M28: 7,262,229 km (0.09 R)
- M29: 8,697,471 km (0.106 R)
- M30: 8,893,444 km (0.057 R)
- M31: 9,091,063 km (0.105 R)
- M32: 9,983,414 km (0.078 R)
- M33: 10,159,341 km (0.101 R)
- M34: 10,277,224 km (0.12 R)
- M35: 10,903,740 km (0.047 R)
- M36: 11,085,053 km (0.081 R)
- M37: 11,944,193 km (0.113 R)
- M38: 12,037,542 km (0.116 R)
- M39: 12,224,988 km (0.094 R)
- M40: 12,666,153 km (0.07 R)
- M41: 13,144,567 km (0.101 R)
- M42: 13,596,502 km (0.098 R)
- M43: 13,955,088 km (0.115 R)
- M44: 14,086,435 km (0.031 R)
- M45: 14,715,195 km (0.085 R)
- M46: 14,848,785 km (0.073 R)
- M47: 15,083,505 km (0.12 R)
- M48: 15,692,817 km (0.054 R)
- M49: 16,241,242 km (0.091 R)
- M50: 16,483,142 km (0.091 R)
- M51: 17,286,333 km (0.097 R)
- M52: 17,604,079 km (0.094 R)
- M53: 18,138,143 km (0.112 R)
- M54: 18,389,169 km (0.097 R)
- M55: 18,497,029 km (0.056 R)
- M56: 19,514,743 km (0.116 R)
- M57: 20,104,308 km (0.112 R)
- M58: 20,364,160 km (0.081 R)
- M59: 20,962,252 km (0.056 R)
- M60: 21,756,018 km (0.107 R)
- M61: 22,252,384 km (0.119 R)
- M62: 22,405,871 km (0.045 R)
- M63: 23,023,262 km (0.083 R)
- M64: 23,178,544 km (0.091 R)
- M65: 23,334,126 km (0.118 R)
- M66: 23,959,894 km (0.075 R)
- M67: 24,353,785 km (0.084 R)
- M68: 24,630,841 km (0.105 R)
- M69: 24,988,679 km (0.081 R)
- M70: 25,148,150 km (0.098 R)
- M71: 25,870,409 km (0.095 R)
- M72: 26,274,622 km (0.108 R)
Planet 6 - Gas Giant
Semi-Major Axis: 5.34 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 714.9
Radius: 11
Gravity: 5.91 G
Time & Orbit
Eccentricity (e): 0.245
Orbit Range: 4.03 AU - 6.65 AU
Year: 4751 Days
Day: 10.7 Hours
Environment
Temp: -144 °C
Axial Tilt: 48.3 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (80)
Outer Limit: 34,984,863 km
- M1: 150,495 km (0.055 R)
- M2: 253,269 km (0.073 R)
- M3: 363,672 km (0.108 R)
- M4: 625,170 km (0.108 R)
- M5: 717,920 km (0.101 R)
- M6: 919,129 km (0.048 R)
- M7: 1,168,210 km (0.112 R)
- M8: 1,407,866 km (0.084 R)
- M9: 1,549,984 km (0.081 R)
- M10: 1,647,372 km (0.118 R)
- M11: 1,814,473 km (0.087 R)
- M12: 2,238,732 km (0.114 R)
- M13: 2,752,601 km (0.115 R)
- M14: 3,177,459 km (0.114 R)
- M15: 3,365,952 km (0.07 R)
- M16: 3,493,559 km (0.108 R)
- M17: 3,886,553 km (0.068 R)
- M18: 4,020,742 km (0.079 R)
- M19: 4,111,099 km (0.089 R)
- M20: 4,316,796 km (0.081 R)
- M21: 5,124,625 km (0.119 R)
- M22: 5,346,329 km (0.088 R)
- M23: 5,927,068 km (0.085 R)
- M24: 6,056,021 km (0.104 R)
- M25: 6,159,992 km (0.115 R)
- M26: 6,238,231 km (0.095 R)
- M27: 6,688,072 km (0.082 R)
- M28: 6,822,411 km (0.04 R)
- M29: 6,984,874 km (0.071 R)
- M30: 7,175,911 km (0.081 R)
- M31: 7,647,294 km (0.08 R)
- M32: 8,445,398 km (0.064 R)
- M33: 8,590,807 km (0.104 R)
- M34: 8,707,643 km (0.105 R)
- M35: 9,510,385 km (0.111 R)
- M36: 10,181,930 km (0.091 R)
- M37: 10,554,728 km (0.107 R)
- M38: 10,837,319 km (0.112 R)
- M39: 11,441,993 km (0.113 R)
- M40: 11,602,960 km (0.086 R)
- M41: 11,797,138 km (0.041 R)
- M42: 12,057,738 km (0.058 R)
- M43: 12,254,310 km (0.057 R)
- M44: 12,684,104 km (0.058 R)
- M45: 13,018,156 km (0.102 R)
- M46: 13,900,036 km (0.111 R)
- M47: 14,175,296 km (0.049 R)
- M48: 15,365,197 km (0.047 R)
- M49: 15,685,636 km (0.05 R)
- M50: 16,080,126 km (0.045 R)
- M51: 16,224,487 km (0.096 R)
- M52: 16,732,821 km (0.068 R)
- M53: 16,805,825 km (0.074 R)
- M54: 16,988,933 km (0.097 R)
- M55: 17,283,341 km (0.093 R)
- M56: 17,728,096 km (0.088 R)
- M57: 17,877,095 km (0.093 R)
- M58: 17,989,144 km (0.025 R)
- M59: 18,139,041 km (0.117 R)
- M60: 18,364,485 km (0.103 R)
- M61: 20,240,742 km (0.094 R)
- M62: 20,435,518 km (0.032 R)
- M63: 20,827,165 km (0.118 R)
- M64: 21,538,353 km (0.095 R)
- M65: 21,697,376 km (0.091 R)
- M66: 21,856,997 km (0.111 R)
- M67: 22,660,337 km (0.117 R)
- M68: 23,391,721 km (0.073 R)
- M69: 23,596,222 km (0.084 R)
- M70: 24,378,768 km (0.116 R)
- M71: 24,544,672 km (0.102 R)
- M72: 25,547,726 km (0.057 R)
- M73: 26,054,264 km (0.092 R)
- M74: 26,521,459 km (0.116 R)
- M75: 26,734,785 km (0.068 R)
- M76: 26,991,495 km (0.073 R)
- M77: 27,077,215 km (0.108 R)
- M78: 27,939,646 km (0.083 R)
- M79: 28,592,491 km (0.109 R)
- M80: 28,986,532 km (0.112 R)
Planet 7 - Gas Giant
Semi-Major Axis: 5.7 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 18.5
Radius: 13.2
Gravity: 0.11 G
Time & Orbit
Eccentricity (e): 0.25
Orbit Range: 4.28 AU - 7.13 AU
Year: 5239 Days
Day: 11.8 Hours
Environment
Temp: -151 °C
Axial Tilt: 27.1 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (26)
Outer Limit: 34,984,863 km
- M1: 248,931 km (0.094 R)
- M2: 708,346 km (0.065 R)
- M3: 830,567 km (0.078 R)
- M4: 1,177,036 km (0.108 R)
- M5: 1,298,210 km (0.088 R)
- M6: 1,857,557 km (0.104 R)
- M7: 2,991,658 km (0.085 R)
- M8: 3,498,645 km (0.059 R)
- M9: 3,878,923 km (0.088 R)
- M10: 4,115,737 km (0.071 R)
- M11: 4,431,687 km (0.047 R)
- M12: 4,887,512 km (0.075 R)
- M13: 5,098,744 km (0.07 R)
- M14: 5,211,242 km (0.112 R)
- M15: 5,427,112 km (0.092 R)
- M16: 5,611,117 km (0.1 R)
- M17: 5,997,528 km (0.079 R)
- M18: 6,332,179 km (0.057 R)
- M19: 6,489,705 km (0.058 R)
- M20: 6,734,447 km (0.089 R)
- M21: 7,423,645 km (0.025 R)
- M22: 7,551,252 km (0.111 R)
- M23: 7,666,891 km (0.104 R)
- M24: 8,187,791 km (0.073 R)
- M25: 8,452,579 km (0.112 R)
- M26: 8,572,706 km (0.114 R)
Planet 8 - Gas Giant
Semi-Major Axis: 6.96 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 213.1
Radius: 9.9
Gravity: 2.17 G
Time & Orbit
Eccentricity (e): 0.177
Orbit Range: 5.73 AU - 8.19 AU
Year: 7069 Days
Day: 6.1 Hours
Environment
Temp: -160 °C
Axial Tilt: 11.2 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (50)
Outer Limit: 34,984,863 km
- M1: 263,143 km (0.108 R)
- M2: 481,406 km (0.029 R)
- M3: 725,400 km (0.089 R)
- M4: 827,276 km (0.054 R)
- M5: 898,036 km (0.104 R)
- M6: 1,438,084 km (0.084 R)
- M7: 1,795,623 km (0.113 R)
- M8: 1,873,713 km (0.08 R)
- M9: 1,984,865 km (0.11 R)
- M10: 2,098,409 km (0.106 R)
- M11: 2,348,986 km (0.087 R)
- M12: 2,716,099 km (0.067 R)
- M13: 3,368,046 km (0.106 R)
- M14: 4,067,117 km (0.061 R)
- M15: 4,191,433 km (0.088 R)
- M16: 5,411,703 km (0.118 R)
- M17: 5,966,561 km (0.069 R)
- M18: 6,466,966 km (0.063 R)
- M19: 6,636,760 km (0.055 R)
- M20: 6,931,318 km (0.081 R)
- M21: 7,995,857 km (0.074 R)
- M22: 8,388,252 km (0.055 R)
- M23: 9,164,964 km (0.075 R)
- M24: 10,132,713 km (0.077 R)
- M25: 10,557,421 km (0.049 R)
- M26: 11,045,858 km (0.108 R)
- M27: 11,482,983 km (0.114 R)
- M28: 11,718,300 km (0.113 R)
- M29: 11,925,643 km (0.089 R)
- M30: 12,373,988 km (0.1 R)
- M31: 15,017,382 km (0.091 R)
- M32: 16,385,754 km (0.102 R)
- M33: 17,319,993 km (0.117 R)
- M34: 17,691,743 km (0.106 R)
- M35: 18,237,177 km (0.102 R)
- M36: 18,719,032 km (0.044 R)
- M37: 19,135,363 km (0.116 R)
- M38: 19,589,841 km (0.106 R)
- M39: 20,012,455 km (0.062 R)
- M40: 20,118,670 km (0.119 R)
- M41: 21,298,548 km (0.063 R)
- M42: 21,443,060 km (0.081 R)
- M43: 21,805,834 km (0.084 R)
- M44: 22,795,424 km (0.072 R)
- M45: 23,351,629 km (0.115 R)
- M46: 23,687,476 km (0.09 R)
- M47: 23,799,675 km (0.118 R)
- M48: 24,137,616 km (0.045 R)
- M49: 24,288,411 km (0.063 R)
- M50: 24,590,748 km (0.11 R)
Planet 9 - Gas Giant
Semi-Major Axis: 7.41 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 399.2
Radius: 14.2
Gravity: 1.98 G
Time & Orbit
Eccentricity (e): 0.178
Orbit Range: 6.09 AU - 8.73 AU
Year: 7766 Days
Day: 6.1 Hours
Environment
Temp: -172 °C
Axial Tilt: 45.8 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (77)
Outer Limit: 34,984,863 km
- M1: 179,667 km (0.079 R)
- M2: 435,779 km (0.113 R)
- M3: 683,513 km (0.091 R)
- M4: 881,580 km (0.055 R)
- M5: 1,506,002 km (0.03 R)
- M6: 1,699,581 km (0.042 R)
- M7: 1,790,387 km (0.085 R)
- M8: 2,112,023 km (0.086 R)
- M9: 2,493,797 km (0.074 R)
- M10: 2,789,402 km (0.102 R)
- M11: 3,096,526 km (0.097 R)
- M12: 3,414,871 km (0.055 R)
- M13: 3,864,263 km (0.059 R)
- M14: 4,083,723 km (0.092 R)
- M15: 4,332,504 km (0.064 R)
- M16: 4,663,564 km (0.113 R)
- M17: 5,002,852 km (0.095 R)
- M18: 5,513,579 km (0.053 R)
- M19: 6,701,237 km (0.115 R)
- M20: 7,234,104 km (0.025 R)
- M21: 7,627,547 km (0.075 R)
- M22: 7,719,400 km (0.077 R)
- M23: 8,090,253 km (0.075 R)
- M24: 8,183,901 km (0.082 R)
- M25: 8,340,829 km (0.094 R)
- M26: 8,657,678 km (0.108 R)
- M27: 8,913,939 km (0.098 R)
- M28: 9,172,893 km (0.087 R)
- M29: 9,500,063 km (0.076 R)
- M30: 9,631,859 km (0.029 R)
- M31: 9,864,334 km (0.073 R)
- M32: 10,199,433 km (0.076 R)
- M33: 10,334,670 km (0.109 R)
- M34: 11,367,194 km (0.045 R)
- M35: 11,612,834 km (0.077 R)
- M36: 11,754,054 km (0.086 R)
- M37: 11,966,932 km (0.079 R)
- M38: 12,181,007 km (0.103 R)
- M39: 12,649,398 km (0.092 R)
- M40: 13,344,728 km (0.114 R)
- M41: 13,939,829 km (0.116 R)
- M42: 14,165,123 km (0.1 R)
- M43: 14,505,608 km (0.113 R)
- M44: 14,657,749 km (0.045 R)
- M45: 15,894,175 km (0.09 R)
- M46: 16,090,448 km (0.07 R)
- M47: 16,366,456 km (0.073 R)
- M48: 18,301,654 km (0.062 R)
- M49: 18,796,673 km (0.117 R)
- M50: 19,254,293 km (0.084 R)
- M51: 19,800,026 km (0.061 R)
- M52: 20,350,696 km (0.097 R)
- M53: 21,035,555 km (0.07 R)
- M54: 22,208,253 km (0.088 R)
- M55: 22,383,881 km (0.102 R)
- M56: 22,780,465 km (0.096 R)
- M57: 22,869,026 km (0.09 R)
- M58: 23,580,963 km (0.112 R)
- M59: 24,616,928 km (0.047 R)
- M60: 24,753,212 km (0.07 R)
- M61: 25,026,527 km (0.062 R)
- M62: 25,621,927 km (0.114 R)
- M63: 26,036,911 km (0.051 R)
- M64: 26,175,738 km (0.088 R)
- M65: 26,454,139 km (0.064 R)
- M66: 27,060,759 km (0.107 R)
- M67: 27,295,179 km (0.084 R)
- M68: 27,624,743 km (0.079 R)
- M69: 28,287,611 km (0.093 R)
- M70: 28,668,786 km (0.087 R)
- M71: 28,812,101 km (0.11 R)
- M72: 30,405,019 km (0.042 R)
- M73: 31,187,566 km (0.086 R)
- M74: 32,274,544 km (0.052 R)
- M75: 32,922,602 km (0.12 R)
- M76: 33,373,789 km (0.095 R)
- M77: 33,726,092 km (0.099 R)
Planet 10 - Gas Giant
Semi-Major Axis: 8.69 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 273.8
Radius: 12.9
Gravity: 1.65 G
Time & Orbit
Eccentricity (e): 0.086
Orbit Range: 7.94 AU - 9.44 AU
Year: 9863 Days
Day: 13.3 Hours
Environment
Temp: -186 °C
Axial Tilt: 22.6 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (72)
Outer Limit: 34,984,863 km
- M1: 244,593 km (0.115 R)
- M2: 369,208 km (0.114 R)
- M3: 597,494 km (0.072 R)
- M4: 904,469 km (0.032 R)
- M5: 1,023,399 km (0.084 R)
- M6: 1,116,449 km (0.107 R)
- M7: 1,311,525 km (0.095 R)
- M8: 2,842,060 km (0.106 R)
- M9: 3,090,243 km (0.094 R)
- M10: 3,251,959 km (0.106 R)
- M11: 3,392,730 km (0.1 R)
- M12: 3,535,746 km (0.114 R)
- M13: 3,901,961 km (0.11 R)
- M14: 4,001,743 km (0.089 R)
- M15: 4,513,517 km (0.079 R)
- M16: 4,724,151 km (0.109 R)
- M17: 4,991,931 km (0.066 R)
- M18: 5,100,539 km (0.098 R)
- M19: 5,292,473 km (0.117 R)
- M20: 5,768,643 km (0.117 R)
- M21: 6,171,211 km (0.069 R)
- M22: 6,523,514 km (0.054 R)
- M23: 6,792,192 km (0.04 R)
- M24: 7,034,092 km (0.053 R)
- M25: 8,511,969 km (0.066 R)
- M26: 8,805,779 km (0.068 R)
- M27: 9,403,273 km (0.111 R)
- M28: 9,504,252 km (0.086 R)
- M29: 10,014,081 km (0.117 R)
- M30: 10,324,347 km (0.051 R)
- M31: 10,637,755 km (0.083 R)
- M32: 12,178,463 km (0.078 R)
- M33: 12,956,073 km (0.051 R)
- M34: 13,559,252 km (0.062 R)
- M35: 14,094,663 km (0.036 R)
- M36: 14,793,285 km (0.058 R)
- M37: 16,629,449 km (0.086 R)
- M38: 16,874,191 km (0.088 R)
- M39: 16,997,011 km (0.059 R)
- M40: 17,243,698 km (0.089 R)
- M41: 17,865,277 km (0.101 R)
- M42: 18,241,815 km (0.101 R)
- M43: 18,325,889 km (0.092 R)
- M44: 19,601,809 km (0.115 R)
- M45: 19,687,977 km (0.08 R)
- M46: 20,906,452 km (0.057 R)
- M47: 21,569,171 km (0.1 R)
- M48: 21,791,623 km (0.116 R)
- M49: 22,508,645 km (0.115 R)
- M50: 23,370,179 km (0.088 R)
- M51: 23,507,211 km (0.097 R)
- M52: 23,965,878 km (0.085 R)
- M53: 24,058,030 km (0.117 R)
- M54: 24,752,464 km (0.117 R)
- M55: 26,541,056 km (0.119 R)
- M56: 26,779,515 km (0.08 R)
- M57: 26,970,851 km (0.112 R)
- M58: 27,162,485 km (0.102 R)
- M59: 27,643,891 km (0.117 R)
- M60: 28,127,990 km (0.113 R)
- M61: 28,225,229 km (0.099 R)
- M62: 29,498,456 km (0.115 R)
- M63: 29,696,075 km (0.052 R)
- M64: 31,443,378 km (0.093 R)
- M65: 32,050,147 km (0.075 R)
- M66: 32,405,891 km (0.058 R)
- M67: 32,814,143 km (0.111 R)
- M68: 33,018,793 km (0.116 R)
- M69: 33,275,354 km (0.086 R)
- M70: 34,411,849 km (0.114 R)
- M71: 34,515,819 km (0.065 R)
- M72: 34,724,059 km (0.103 R)
Kuiper Belt
Range: 30 - 46 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 328 - 11,225 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.