outfly/doc/research.md

# Planetary/Moon data table

| Name | Radius (km) | Mean orbit radius (km) |
| ---- | ----------- | ---------------------- |
| Earth | 6371 | 149,598,023 |
| [Jupiter](https://en.wikipedia.org/wiki/Jupiter) | 69,911 | 778,479,000 |
| [Metis](https://en.wikipedia.org/wiki/Metis_(moon)) | 21.5 | 128,000 |
| [Adrastea](https://en.wikipedia.org/wiki/Adrastea_(moon)) | 8.2 | 129,000 |
| [Amalthea](https://en.wikipedia.org/wiki/Amalthea_(moon)) | 83.5 | 181,365 |
| [Thebe](https://en.wikipedia.org/wiki/Thebe_(moon)) | 49.3 | 221,889 |
| Luna | 1737 | 384,399 |
| [Io](https://en.wikipedia.org/wiki/Io_(moon)) | 1822 | 421,700 |
| [Europa](https://en.wikipedia.org/wiki/Europa_(moon)) | 1561 | 670,900 |
| [Ganymede](https://en.wikipedia.org/wiki/Ganymede_(moon)) | 2634 | 1,070,400 |
| [Callisto](https://en.wikipedia.org/wiki/Callisto_(moon)) | 2410 | 1,883,000 |
| [Himalia](https://en.wikipedia.org/wiki/Himalia_(moon)) (largest irregular) | 85 | 11,460,000 |

# Missions to Jupiter

- [Galileo](https://en.wikipedia.org/wiki/Galileo_project) orbiter (1995-2003)
    - [Encountered asteroid 243 Ida](https://en.wikipedia.org/wiki/243_Ida)
    - [Observed Shoemaker-Levy-9](https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9)
    - [Dropped an atmospheric probe into jupiter](https://science.nasa.gov/mission/galileo-jupiter-atmospheric-probe)
- [Juno](https://en.wikipedia.org/wiki/Juno_(spacecraft)) orbiter (2016-now)
    - Auroras
    - Magnetic Field
    - Map atmosphere composition
- [New Horizons](https://en.wikipedia.org/wiki/New_Horizons#Jupiter_encounter) flyby (2007)
    - Atmosphere conditions
    - Photos of moons
- [Europa Clipper](https://en.wikipedia.org/wiki/Europa_Clipper) orbiter (arrives 2030)
- [Jupiter Icy Moons Explorer](https://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Explorer) orbiter (arrives 2031)

# Magnetosphere

- [Of Jupiter](https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter)

# Atmosphere

- 1 Pa = 1N/m² = 1kg/(m\*s²)
- 1 bar = 100,000 Pa
- Earth sea level: 1.013 bar = 1013 hPa

## Jupiter

- SRC1: [Thermal structure of Jupiter's atmosphere near the edge of a 5µm hot spot in the north equatorial belt](https://doi.org/10.1029/98JE01766)
- SRC2: [NASA Jupiter Fact Sheet](https://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html)
- SRC3: ["THE INTERIORS OF JUPITER AND SATURN" by Ravit Helled](https://arxiv.org/pdf/1812.07436)

Based on Table 8 from SRC1, with additional values for altitude=0 from SRC2 and interior density values from SRC3:

| Altitude (km) | Pressure (bar) | Temperature (K) | Density (kg/m³) |
| ------------- | -------------- | --------------- | --------------- |
| 1029.2 | 9.63E-10 | 899.9 | 2.58E-11 |
| 1020 | 1.02E-09 | 903.4 | 2.71E-11 |
| 1000 | 1.15E-09 | 897 | 3.08E-11 |
| 980 | 1.30E-09 | 883.9 | 3.54E-11 |
| 960 | 1.47E-09 | 872.2 | 4.06E-11 |
| 940 | 1.66E-09 | 866 | 4.64E-11 |
| 920 | 1.89E-09 | 865.4 | 5.26E-11 |
| 900 | 2.14E-09 | 869.1 | 5.95E-11 |
| 880 | 2.43E-09 | 875.2 | 6.70E-11 |
| 860 | 2.75E-09 | 881.4 | 7.54E-11 |
| 840 | 3.11E-09 | 885.2 | 8.50E-11 |
| 820 | 3.52E-09 | 884.4 | 9.64E-11 |
| 800 | 3.99E-09 | 877.2 | 1.10E-10 |
| 780 | 4.53E-09 | 862.2 | 1.27E-10 |
| 760 | 5.15E-09 | 840 | 1.49E-10 |
| 740 | 5.89E-09 | 812 | 1.76E-10 |
| 720 | 6.77E-09 | 776.1 | 2.12E-10 |
| 700 | 7.83E-09 | 741 | 2.57E-10 |
| 680 | 9.12E-09 | 712.8 | 3.11E-10 |
| 660 | 1.07E-08 | 692.7 | 3.76E-10 |
| 640 | 1.26E-08 | 680.2 | 4.51E-10 |
| 620 | 1.48E-08 | 674.6 | 5.36E-10 |
| 600 | 1.75E-08 | 669.8 | 6.39E-10 |
| 580 | 2.06E-08 | 670.3 | 7.56E-10 |
| 560 | 2.45E-08 | 664 | 9.05E-10 |
| 540 | 2.90E-08 | 642.4 | 1.11E-09 |
| 520 | 3.48E-08 | 594.3 | 1.45E-09 |
| 500 | 4.26E-08 | 545.9 | 1.94E-09 |
| 480 | 5.27E-08 | 535.8 | 2.46E-09 |
| 460 | 6.52E-08 | 535.7 | 3.06E-09 |
| 440 | 8.15E-08 | 483.1 | 4.28E-09 |
| 420 | 1.07E-07 | 392.9 | 6.99E-09 |
| 400 | 1.46E-07 | 370.2 | 1.02E-08 |
| 380 | 2.11E-07 | 289.2 | 1.92E-08 |
| 360 | 3.37E-07 | 231.7 | 3.89E-08 |
| 340 | 6.04E-07 | 198.6 | 8.25E-08 |
| 320 | 1.15E-06 | 194.2 | 1.63E-07 |
| 300 | 2.18E-06 | 177.6 | 3.42E-07 |
| 280 | 4.80E-06 | 152.8 | 8.71E-07 |
| 260 | 1.09E-05 | 151 | 2.01E-06 |
| 240 | 2.48E-05 | 155.7 | 4.42E-06 |
| 220 | 5.59E-05 | 157.2 | 9.88E-06 |
| 200 | 1.26E-04 | 158.2 | 2.21E-05 |
| 180 | 2.82E-04 | 157.4 | 4.98E-05 |
| 160 | 6.19E-04 | 168.6 | 0.000102 |
| 140 | 1.34E-03 | 160.5 | 0.0002325 |
| 120 | 3.08E-03 | 149.8 | 0.000571 |
| 100 | 7.18E-03 | 158.1 | 0.001261 |
| 80 | 1.64E-02 | 143.8 | 0.003168 |
| 60 | 4.37E-02 | 122.6 | 0.009915 |
| 40 | 1.36E-01 | 113.2 | 0.03335 |
| 23.3 | 3.52E-01 | 122.9 | 0.07945 |
| 0 | 1 | 165 | 0.16 |
| -62000 | ? | ? | 4500 |
| -62500 | ? | ? | 20000 |
| -70000 | ? | ? | 25000 |

### Regression analysis

Pressure:

- 500km-1029.2km: `p[bar](x[m]) = exp(-13.3961516218 - 0.0000071595 * x)`
- 200km-500km: `p[bar](x[m]) = exp(-3.4340885227 - 0.0000277865 * x)`
- 0km-200km: `p[bar](x[m]) = exp(-0.0020248515 - 0.0000454102 * x)`
- <0km: `p[bar](x[m]) = -(1.45773e-16) * x^3 + 1` (low-effort cubic regression on `[(-70000km, 50Mbar), (0m, 1bar)]`)

Density:

- 500km-1029.2km: `rho[kg/m³](x[m]) = exp(-15.98781474626208 - 0.00000816092074*x)`
- 200km-500km: `rho[kg/m³](x[m]) = exp(-4.22487505187567 - 0.00003251947782*x)`
- 0km-200km: `rho[kg/m³](x[m]) = exp(-1.83275074106303 - 0.00004486861245*x)`
- -62000km-0km: `rho[kg/m³](x[m]) = -0.0000725781*x + 0.16` (linear regression)
- -70000km-62000km: `rho[kg/m³](x[m]) = 25000.0 / (1 + exp(0.00000580528 * x + 361.44394)))` (logistic regression)

### Designing the in-game atmosphere

New mechanics:

- [X] Ambient Pressure
    - [X] Depends on altitude
- [ ] Temperature
    - [ ] Ambient temperature
    - [ ] Space suit temperature
    - [ ] Vehicle temperature
    - [ ] Air temperature inside?
- [ ] Wind
    - [ ] [Depends on latitude](https://en.wikipedia.org/w/index.php?title=Atmosphere_of_Jupiter&oldid=1255052800#Zones,_belts_and_jets)
    - [ ] [Needs to account for vortices, red spots](https://en.wikipedia.org/w/index.php?title=Atmosphere_of_Jupiter&oldid=1255052800#Vortices)
- [ ] Hydrogen (resource)?

Relations between mechanics:

- [X] Pressure decelerates you
    - [X] relative to the motion of the planet
    - [ ] accounting for the wind
    - [X] scaled by your surface area
- [ ] Ambient temperature heats up suit/vehicle temperature, depending on density
- [ ] [Buoyancy](https://en.wikipedia.org/wiki/Buoyancy): upward acceleration depending on densities (yours and ambient), altitude (gravitational acceleration), and your mass
    - Negligible for any current vehicles but could be cool for zeppelins
- [X] [Drag?](https://en.wikipedia.org/wiki/Drag_(physics)) (with different drag coefficients depending on vehicle and angle)
    - [X] [Form drag](https://en.wikipedia.org/wiki/Parasitic_drag#Form_drag)
    - [ ] [Lift-induced drag](https://en.wikipedia.org/wiki/Lift-induced_drag)
- [X] Death at pressure of ~1000 bar through implosion (depending on vehicle)
- [ ] Death at high temperatures through continuous damage when temperature exceeds 60°C
- [ ] Hydrogen + Oxygen = Water, used for evaporative cooling (works only at right pressure/temperature)
- [ ] Refill Hydrogen inside Jupiter's atmosphere

## Io

- Video of Tvashtar volcano: https://photojournal.jpl.nasa.gov/catalog/PIA09665

# Chemistry

- [X] Oxygen
- [ ] Hydrogen

## Uses

- [X] Oxygen
    - [X] Breathing
- [ ] Hydrogen
    - [ ] Thruster fuel? (reacting with O2?)
    - [ ] Ion engine?
- [ ] Water (H2O)
    - [ ] Evaporative cooling?
- [ ] [Hydrogen Peroxide](https://en.wikipedia.org/wiki/Hydrogen_peroxide)? (H2O2)
    - Does this have any uses?