Star System Generated (Seed: 1766320029)
Star Details
Spectral Class: F0V
Temperature: 7,400 K
Mass: 1.63 sol
Luminosity: 5.53 lux
Habitable Zone (HZ)
Inner Boundary: 2.24 AU
Outer Boundary: 3.23 AU
Physical Limits
Snow Line: 11.29 AU
Max System Radius: 25.5 AU
Planetary System (10 Planets)
Planet 1 - Terrestrial
Semi-Major Axis: 0.5 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 4.05
Radius: 1.75
Gravity: 1.32 G
Time & Orbit
Eccentricity (e): 0.069
Orbit Range: 0.47 AU - 0.53 AU
Year: 101 Days
Day: 42.5 Hours
Environment
Temp: 470 °C
Axial Tilt: 12.7 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Satellites (1)
Outer Limit: 87,431,653 km
- M1: 229,633 km (0.089 R)
Planet 2 - Terrestrial
Semi-Major Axis: 1.82 AU
Status: Inner (Hot)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 1.59
Radius: 1.2
Gravity: 1.1 G
Time & Orbit
Eccentricity (e): 0.199
Orbit Range: 1.46 AU - 2.18 AU
Year: 702 Days
Day: 26 Hours
Environment
Temp: 120 °C
Axial Tilt: 31.9 °
Atmosphere: Dense COâ‚‚
Biome: Volcanic/Barren
Planet 3 - Terrestrial
Semi-Major Axis: 2.32 AU
Status: HZ
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 2.2
Radius: 1.37
Gravity: 1.17 G
Time & Orbit
Eccentricity (e): 0.08
Orbit Range: 2.13 AU - 2.51 AU
Year: 1011 Days
Day: 29.3 Hours
Environment
Temp: 25 °C
Axial Tilt: 27.6 °
Atmosphere: Nâ‚‚, Oâ‚‚
Biome: Arid/Tundra
Planet 4 - Terrestrial
Semi-Major Axis: 5.46 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.18
Radius: 0.5
Gravity: 0.72 G
Time & Orbit
Eccentricity (e): 0.165
Orbit Range: 4.56 AU - 6.36 AU
Year: 3650 Days
Day: 42.5 Hours
Environment
Temp: -79 °C
Axial Tilt: 6 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Planet 5 - Terrestrial
Semi-Major Axis: 5.59 AU
Status: Outer (Cold)
Composition: Rocky (Silicates/Metals)
Physical Data
Mass: 0.68
Radius: 0.86
Gravity: 0.92 G
Time & Orbit
Eccentricity (e): 0.059
Orbit Range: 5.26 AU - 5.92 AU
Year: 3781 Days
Day: 22.4 Hours
Environment
Temp: -91 °C
Axial Tilt: 29.9 °
Atmosphere: Thin Nâ‚‚/CHâ‚„
Biome: Ice Cap/Desert
Satellites (1)
Outer Limit: 87,431,653 km
- M1: 34,856 km (0.105 R)
Asteroid Belt
Center: 9.03 AU
Composition
Type: Inner (Rocky/Metallic)
A dense region of planetesimals and debris.
Boundary
Planet 6 - Gas Giant
Semi-Major Axis: 12.47 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 238.8
Radius: 10.3
Gravity: 2.25 G
Time & Orbit
Eccentricity (e): 0.175
Orbit Range: 10.29 AU - 14.65 AU
Year: 12598 Days
Day: 13.2 Hours
Environment
Temp: -142 °C
Axial Tilt: 26.9 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (77)
Outer Limit: 87,431,653 km
- M1: 131,646 km (0.059 R)
- M2: 230,830 km (0.112 R)
- M3: 553,512 km (0.1 R)
- M4: 733,628 km (0.049 R)
- M5: 870,061 km (0.079 R)
- M6: 1,677,740 km (0.063 R)
- M7: 1,945,371 km (0.096 R)
- M8: 2,052,034 km (0.078 R)
- M9: 2,160,642 km (0.103 R)
- M10: 2,293,635 km (0.103 R)
- M11: 2,685,581 km (0.1 R)
- M12: 2,828,896 km (0.056 R)
- M13: 3,688,934 km (0.057 R)
- M14: 3,821,926 km (0.097 R)
- M15: 4,482,700 km (0.111 R)
- M16: 5,268,089 km (0.11 R)
- M17: 6,001,717 km (0.101 R)
- M18: 6,508,555 km (0.118 R)
- M19: 7,161,549 km (0.101 R)
- M20: 7,428,581 km (0.113 R)
- M21: 7,733,013 km (0.098 R)
- M22: 7,801,230 km (0.089 R)
- M23: 9,135,044 km (0.108 R)
- M24: 9,680,777 km (0.101 R)
- M25: 9,976,233 km (0.106 R)
- M26: 10,162,333 km (0.087 R)
- M27: 10,462,725 km (0.103 R)
- M28: 11,033,591 km (0.1 R)
- M29: 11,303,466 km (0.054 R)
- M30: 11,419,853 km (0.119 R)
- M31: 12,007,473 km (0.102 R)
- M32: 12,205,541 km (0.072 R)
- M33: 12,484,690 km (0.11 R)
- M34: 13,334,855 km (0.045 R)
- M35: 14,287,345 km (0.083 R)
- M36: 14,835,471 km (0.066 R)
- M37: 15,005,414 km (0.099 R)
- M38: 15,778,536 km (0.118 R)
- M39: 16,126,351 km (0.041 R)
- M40: 17,095,745 km (0.1 R)
- M41: 17,229,486 km (0.055 R)
- M42: 17,497,865 km (0.054 R)
- M43: 18,129,467 km (0.056 R)
- M44: 18,402,483 km (0.082 R)
- M45: 18,585,142 km (0.113 R)
- M46: 18,814,475 km (0.115 R)
- M47: 19,275,835 km (0.06 R)
- M48: 19,554,386 km (0.071 R)
- M49: 20,162,651 km (0.087 R)
- M50: 20,682,205 km (0.106 R)
- M51: 20,872,194 km (0.099 R)
- M52: 21,015,210 km (0.104 R)
- M53: 21,686,306 km (0.089 R)
- M54: 21,927,757 km (0.07 R)
- M55: 22,170,105 km (0.095 R)
- M56: 23,592,931 km (0.089 R)
- M57: 23,890,930 km (0.11 R)
- M58: 23,990,562 km (0.117 R)
- M59: 24,240,241 km (0.064 R)
- M60: 24,691,877 km (0.082 R)
- M61: 25,045,077 km (0.044 R)
- M62: 25,146,355 km (0.079 R)
- M63: 25,858,740 km (0.118 R)
- M64: 26,732,541 km (0.102 R)
- M65: 28,087,898 km (0.111 R)
- M66: 28,245,724 km (0.112 R)
- M67: 30,216,227 km (0.115 R)
- M68: 30,485,952 km (0.052 R)
- M69: 32,285,764 km (0.08 R)
- M70: 32,838,079 km (0.057 R)
- M71: 33,115,284 km (0.057 R)
- M72: 34,738,870 km (0.115 R)
- M73: 36,617,669 km (0.112 R)
- M74: 37,078,131 km (0.038 R)
- M75: 37,424,750 km (0.103 R)
- M76: 38,295,858 km (0.102 R)
- M77: 38,997,622 km (0.037 R)
Planet 7 - Gas Giant
Semi-Major Axis: 12.92 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 11.3
Radius: 11.8
Gravity: 0.08 G
Time & Orbit
Eccentricity (e): 0.081
Orbit Range: 11.87 AU - 13.97 AU
Year: 13286 Days
Day: 10.9 Hours
Environment
Temp: -155 °C
Axial Tilt: 14.2 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (24)
Outer Limit: 87,431,653 km
- M1: 176,226 km (0.084 R)
- M2: 452,683 km (0.089 R)
- M3: 657,782 km (0.089 R)
- M4: 879,037 km (0.095 R)
- M5: 969,544 km (0.089 R)
- M6: 1,152,053 km (0.098 R)
- M7: 1,482,066 km (0.092 R)
- M8: 1,809,985 km (0.097 R)
- M9: 3,169,829 km (0.116 R)
- M10: 3,648,094 km (0.073 R)
- M11: 4,495,266 km (0.051 R)
- M12: 4,568,719 km (0.115 R)
- M13: 4,731,481 km (0.112 R)
- M14: 6,595,621 km (0.069 R)
- M15: 6,864,298 km (0.076 R)
- M16: 7,068,200 km (0.077 R)
- M17: 7,308,754 km (0.094 R)
- M18: 7,656,868 km (0.12 R)
- M19: 9,478,222 km (0.043 R)
- M20: 10,711,208 km (0.072 R)
- M21: 12,591,503 km (0.079 R)
- M22: 12,695,474 km (0.11 R)
- M23: 13,367,617 km (0.108 R)
- M24: 13,601,289 km (0.102 R)
Planet 8 - Gas Giant
Semi-Major Axis: 16.03 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 522
Radius: 14.1
Gravity: 2.63 G
Time & Orbit
Eccentricity (e): 0.158
Orbit Range: 13.5 AU - 18.56 AU
Year: 18361 Days
Day: 5.1 Hours
Environment
Temp: -154 °C
Axial Tilt: 20.8 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (87)
Outer Limit: 87,431,653 km
- M1: 186,100 km (0.066 R)
- M2: 283,787 km (0.106 R)
- M3: 738,864 km (0.048 R)
- M4: 1,336,358 km (0.117 R)
- M5: 1,574,218 km (0.03 R)
- M6: 1,797,867 km (0.117 R)
- M7: 2,032,287 km (0.079 R)
- M8: 2,183,979 km (0.115 R)
- M9: 2,728,665 km (0.076 R)
- M10: 3,034,294 km (0.088 R)
- M11: 3,350,992 km (0.118 R)
- M12: 3,865,459 km (0.118 R)
- M13: 4,093,746 km (0.11 R)
- M14: 4,248,280 km (0.033 R)
- M15: 4,365,565 km (0.115 R)
- M16: 5,258,964 km (0.113 R)
- M17: 5,555,018 km (0.092 R)
- M18: 5,943,823 km (0.084 R)
- M19: 6,341,603 km (0.026 R)
- M20: 6,611,627 km (0.117 R)
- M21: 6,977,544 km (0.119 R)
- M22: 7,070,145 km (0.067 R)
- M23: 9,928,063 km (0.038 R)
- M24: 10,453,151 km (0.089 R)
- M25: 10,665,879 km (0.059 R)
- M26: 11,312,441 km (0.116 R)
- M27: 11,805,666 km (0.083 R)
- M28: 12,082,870 km (0.086 R)
- M29: 12,194,321 km (0.099 R)
- M30: 13,965,410 km (0.109 R)
- M31: 14,791,489 km (0.036 R)
- M32: 15,331,089 km (0.06 R)
- M33: 15,512,252 km (0.12 R)
- M34: 17,112,949 km (0.082 R)
- M35: 18,765,706 km (0.056 R)
- M36: 19,089,436 km (0.08 R)
- M37: 19,284,512 km (0.1 R)
- M38: 19,611,234 km (0.091 R)
- M39: 19,873,778 km (0.077 R)
- M40: 20,668,741 km (0.074 R)
- M41: 21,406,558 km (0.064 R)
- M42: 22,701,477 km (0.103 R)
- M43: 23,601,906 km (0.098 R)
- M44: 23,741,481 km (0.073 R)
- M45: 26,156,290 km (0.053 R)
- M46: 27,466,019 km (0.104 R)
- M47: 29,320,435 km (0.11 R)
- M48: 30,756,724 km (0.063 R)
- M49: 31,215,092 km (0.107 R)
- M50: 32,837,032 km (0.057 R)
- M51: 33,227,333 km (0.093 R)
- M52: 33,776,207 km (0.101 R)
- M53: 35,440,783 km (0.09 R)
- M54: 35,600,852 km (0.114 R)
- M55: 36,001,625 km (0.04 R)
- M56: 36,727,025 km (0.069 R)
- M57: 37,946,697 km (0.105 R)
- M58: 38,192,336 km (0.107 R)
- M59: 38,849,669 km (0.113 R)
- M60: 39,676,497 km (0.063 R)
- M61: 40,927,883 km (0.092 R)
- M62: 41,938,267 km (0.118 R)
- M63: 43,383,682 km (0.076 R)
- M64: 43,897,700 km (0.089 R)
- M65: 45,365,105 km (0.073 R)
- M66: 45,973,969 km (0.077 R)
- M67: 46,673,189 km (0.116 R)
- M68: 48,525,361 km (0.094 R)
- M69: 48,702,933 km (0.077 R)
- M70: 49,237,147 km (0.072 R)
- M71: 49,594,387 km (0.083 R)
- M72: 51,122,380 km (0.064 R)
- M73: 51,665,270 km (0.028 R)
- M74: 52,301,211 km (0.08 R)
- M75: 52,665,631 km (0.045 R)
- M76: 53,672,425 km (0.104 R)
- M77: 55,798,061 km (0.067 R)
- M78: 56,824,302 km (0.082 R)
- M79: 57,668,633 km (0.098 R)
- M80: 58,895,485 km (0.073 R)
- M81: 59,274,716 km (0.118 R)
- M82: 60,417,344 km (0.07 R)
- M83: 61,087,243 km (0.085 R)
- M84: 62,531,012 km (0.076 R)
- M85: 63,402,719 km (0.036 R)
- M86: 65,060,114 km (0.118 R)
- M87: 65,256,087 km (0.078 R)
Planet 9 - Gas Giant
Semi-Major Axis: 18.26 AU
Status: Outer (Cold)
Composition: Hydrogen/Helium Atmosphere
Physical Data
Mass: 860.2
Radius: 11.2
Gravity: 6.86 G
Time & Orbit
Eccentricity (e): 0.175
Orbit Range: 15.06 AU - 21.46 AU
Year: 22323 Days
Day: 5.2 Hours
Environment
Temp: -173 °C
Axial Tilt: 33.5 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (90)
Outer Limit: 87,431,653 km
- M1: 142,118 km (0.101 R)
- M2: 241,002 km (0.097 R)
- M3: 981,063 km (0.1 R)
- M4: 2,441,437 km (0.075 R)
- M5: 2,721,484 km (0.062 R)
- M6: 3,356,677 km (0.083 R)
- M7: 3,623,560 km (0.089 R)
- M8: 3,805,321 km (0.055 R)
- M9: 4,225,242 km (0.116 R)
- M10: 5,109,665 km (0.099 R)
- M11: 5,783,454 km (0.095 R)
- M12: 6,050,037 km (0.062 R)
- M13: 6,375,412 km (0.058 R)
- M14: 6,818,073 km (0.105 R)
- M15: 8,264,983 km (0.112 R)
- M16: 9,239,464 km (0.116 R)
- M17: 10,057,914 km (0.098 R)
- M18: 10,314,324 km (0.067 R)
- M19: 10,768,504 km (0.065 R)
- M20: 11,361,958 km (0.116 R)
- M21: 11,830,948 km (0.101 R)
- M22: 12,374,736 km (0.087 R)
- M23: 12,649,697 km (0.048 R)
- M24: 13,275,614 km (0.106 R)
- M25: 15,067,198 km (0.085 R)
- M26: 15,804,865 km (0.115 R)
- M27: 16,178,112 km (0.113 R)
- M28: 17,009,577 km (0.12 R)
- M29: 17,932,446 km (0.118 R)
- M30: 19,267,607 km (0.089 R)
- M31: 20,067,956 km (0.11 R)
- M32: 21,042,586 km (0.052 R)
- M33: 21,618,239 km (0.107 R)
- M34: 22,199,127 km (0.119 R)
- M35: 23,461,135 km (0.03 R)
- M36: 23,631,078 km (0.097 R)
- M37: 25,790,823 km (0.12 R)
- M38: 26,583,691 km (0.09 R)
- M39: 29,101,124 km (0.068 R)
- M40: 29,558,744 km (0.093 R)
- M41: 30,203,212 km (0.111 R)
- M42: 31,506,209 km (0.11 R)
- M43: 31,881,849 km (0.084 R)
- M44: 33,112,890 km (0.098 R)
- M45: 33,208,334 km (0.112 R)
- M46: 33,782,341 km (0.074 R)
- M47: 35,426,421 km (0.085 R)
- M48: 36,012,845 km (0.115 R)
- M49: 36,602,560 km (0.111 R)
- M50: 37,891,196 km (0.099 R)
- M51: 38,490,934 km (0.108 R)
- M52: 39,598,706 km (0.073 R)
- M53: 39,902,539 km (0.107 R)
- M54: 40,207,270 km (0.115 R)
- M55: 42,672,493 km (0.042 R)
- M56: 42,776,314 km (0.119 R)
- M57: 44,238,035 km (0.085 R)
- M58: 44,764,171 km (0.063 R)
- M59: 44,869,637 km (0.075 R)
- M60: 46,568,022 km (0.085 R)
- M61: 46,781,947 km (0.061 R)
- M62: 48,395,659 km (0.045 R)
- M63: 51,125,820 km (0.088 R)
- M64: 53,681,251 km (0.066 R)
- M65: 54,017,697 km (0.114 R)
- M66: 55,710,097 km (0.094 R)
- M67: 56,278,121 km (0.03 R)
- M68: 57,534,593 km (0.116 R)
- M69: 57,878,818 km (0.107 R)
- M70: 61,124,792 km (0.106 R)
- M71: 63,242,500 km (0.115 R)
- M72: 64,667,569 km (0.112 R)
- M73: 65,983,282 km (0.058 R)
- M74: 66,103,260 km (0.072 R)
- M75: 66,343,514 km (0.041 R)
- M76: 67,549,423 km (0.085 R)
- M77: 68,884,284 km (0.028 R)
- M78: 69,493,896 km (0.087 R)
- M79: 69,982,931 km (0.111 R)
- M80: 72,445,013 km (0.107 R)
- M81: 73,189,113 km (0.07 R)
- M82: 73,313,279 km (0.097 R)
- M83: 74,935,219 km (0.085 R)
- M84: 78,468,571 km (0.047 R)
- M85: 79,105,260 km (0.113 R)
- M86: 79,232,717 km (0.109 R)
- M87: 82,314,134 km (0.093 R)
- M88: 84,129,654 km (0.104 R)
- M89: 84,259,804 km (0.103 R)
- M90: 85,303,698 km (0.088 R)
Planet 10 - Ice Giant
Semi-Major Axis: 18.62 AU
Status: Outer (Cold)
Composition: Methane/Ammonia Ices
Physical Data
Mass: 786.8
Radius: 4.7
Gravity: 35.62 G
Time & Orbit
Eccentricity (e): 0.063
Orbit Range: 17.45 AU - 19.79 AU
Year: 22986 Days
Day: 20.2 Hours
Environment
Temp: -155 °C
Axial Tilt: 46.8 °
Atmosphere: Hâ‚‚, CHâ‚„
Biome: None
Satellites (94)
Outer Limit: 87,431,653 km
- M1: 80,484 km (0.088 R)
- M2: 173,234 km (0.083 R)
- M3: 324,328 km (0.097 R)
- M4: 512,522 km (0.112 R)
- M5: 892,501 km (0.096 R)
- M6: 1,216,380 km (0.115 R)
- M7: 1,310,627 km (0.11 R)
- M8: 2,072,678 km (0.114 R)
- M9: 2,904,742 km (0.086 R)
- M10: 3,159,507 km (0.098 R)
- M11: 3,873,538 km (0.116 R)
- M12: 4,106,611 km (0.073 R)
- M13: 4,201,157 km (0.084 R)
- M14: 4,783,242 km (0.084 R)
- M15: 5,033,220 km (0.077 R)
- M16: 5,185,212 km (0.097 R)
- M17: 5,338,699 km (0.088 R)
- M18: 5,650,312 km (0.12 R)
- M19: 7,123,851 km (0.085 R)
- M20: 7,640,113 km (0.065 R)
- M21: 9,012,973 km (0.045 R)
- M22: 9,135,942 km (0.087 R)
- M23: 9,508,141 km (0.101 R)
- M24: 9,759,017 km (0.113 R)
- M25: 9,821,998 km (0.04 R)
- M26: 12,865,417 km (0.07 R)
- M27: 15,358,615 km (0.054 R)
- M28: 15,505,520 km (0.088 R)
- M29: 15,800,677 km (0.102 R)
- M30: 16,172,128 km (0.078 R)
- M31: 16,471,474 km (0.091 R)
- M32: 16,999,704 km (0.075 R)
- M33: 21,175,130 km (0.109 R)
- M34: 21,420,470 km (0.089 R)
- M35: 22,996,334 km (0.05 R)
- M36: 23,164,482 km (0.118 R)
- M37: 23,248,556 km (0.079 R)
- M38: 23,501,676 km (0.045 R)
- M39: 24,266,570 km (0.094 R)
- M40: 24,609,149 km (0.111 R)
- M41: 24,781,037 km (0.042 R)
- M42: 26,345,831 km (0.111 R)
- M43: 28,481,490 km (0.078 R)
- M44: 28,933,275 km (0.114 R)
- M45: 29,205,544 km (0.117 R)
- M46: 30,487,298 km (0.1 R)
- M47: 30,764,353 km (0.086 R)
- M48: 31,042,306 km (0.105 R)
- M49: 32,538,285 km (0.047 R)
- M50: 33,200,255 km (0.055 R)
- M51: 35,600,104 km (0.082 R)
- M52: 37,460,952 km (0.074 R)
- M53: 37,658,721 km (0.12 R)
- M54: 38,552,718 km (0.057 R)
- M55: 40,564,360 km (0.08 R)
- M56: 40,869,091 km (0.1 R)
- M57: 41,685,297 km (0.068 R)
- M58: 42,713,034 km (0.064 R)
- M59: 43,333,716 km (0.034 R)
- M60: 43,853,269 km (0.086 R)
- M61: 45,529,514 km (0.044 R)
- M62: 46,587,769 km (0.046 R)
- M63: 47,440,178 km (0.103 R)
- M64: 48,082,850 km (0.057 R)
- M65: 48,836,374 km (0.101 R)
- M66: 51,010,480 km (0.077 R)
- M67: 52,772,444 km (0.071 R)
- M68: 53,105,000 km (0.089 R)
- M69: 54,666,204 km (0.078 R)
- M70: 55,790,581 km (0.09 R)
- M71: 56,809,043 km (0.072 R)
- M72: 57,833,639 km (0.092 R)
- M73: 59,439,423 km (0.113 R)
- M74: 59,554,763 km (0.113 R)
- M75: 61,875,624 km (0.102 R)
- M76: 62,460,402 km (0.075 R)
- M77: 63,517,760 km (0.043 R)
- M78: 65,293,038 km (0.064 R)
- M79: 65,411,968 km (0.119 R)
- M80: 65,888,437 km (0.109 R)
- M81: 67,444,854 km (0.105 R)
- M82: 69,134,562 km (0.082 R)
- M83: 70,227,972 km (0.115 R)
- M84: 72,678,535 km (0.099 R)
- M85: 74,410,430 km (0.068 R)
- M86: 74,534,746 km (0.106 R)
- M87: 74,783,377 km (0.111 R)
- M88: 76,406,364 km (0.112 R)
- M89: 82,242,028 km (0.031 R)
- M90: 83,787,823 km (0.091 R)
- M91: 84,693,937 km (0.099 R)
- M92: 85,863,643 km (0.058 R)
- M93: 86,777,237 km (0.107 R)
- M94: 87,431,728 km (0.063 R)
Kuiper Belt
Range: 38.3 - 64.3 AU
Composition
Type: Dwarf Planets/TNOs (Ices)
Reservoir of dwarf planets and volatile ices.
Outer System
Oort Cloud
Range: 357 - 14,818 AU
Composition
Type: Cometary Reservoir
System's final boundary, containing trillions of icy planetesimals.