Difference between revisions of "Eve"

Revision as of 00:32, 26 August 2023

Eve
Eve as seen from orbit.
Planet of Kerbol
Orbital Characteristics
Semi-major axis		9 832 684 544 m [Note 1]
Apoapsis		9 931 011 387 m [Note 1]
Periapsis		9 734 357 701 m [Note 1]
Orbital eccentricity		0.01
Orbital inclination		2.1 °
Argument of periapsis		0 °
Longitude of the ascending node		15 °
Mean anomaly		3.14 rad (at 0s UT)
Sidereal orbital period		5 657 995 s
		261 d 5 h 39 m 55.1 s
Synodic orbital period		14 687 035.5 s
Orbital velocity		10 811 - 11 029 m/s
Physical Characteristics
Equatorial radius		700 000 m
Equatorial circumference		4 398 230 m
Surface area		6.1575216×1012 m2
Mass		1.2243980×1023 kg
Standard gravitational parameter		8.1717302×1012 m3/s2
Density		85 219.677 kg/m3
Surface gravity		16.7 m/s2 (1.701 g)
Escape velocity		4 831.96 m/s
Sidereal rotation period		80 500.000 s
		3 d 4 h 21 m 40 s
Solar day		81 661.857 s
		3 d 4 h 41 m 1.9 s
Sidereal rotational velocity		54.636 m/s
Synchronous orbit		10 328.47 km
Sphere of influence		85 109 365 m [Note 1]
Atmospheric Characteristics
Atmosphere present		Yes
Atmospheric pressure		506.625 kPa
		5 atm
Atmospheric height		90 000 m
		5.0×10-6 atm
Temperaturemin		-113.13 °C 160.02 K
Temperaturemax		146.85 °C 420 K
Oxygen present		No
Scientific multiplier
Surface		8
Splashed		8
Lower atmosphere		6
Upper atmosphere		6
Near space		7
Outer space		5
Recovery		5
↑ 1.0 1.1 1.2 1.3 The distances are given from the body's center, not from the surface (unlike ingame)

Eve is the second planet from Kerbol, the closest planet to Kerbin, and KSP's analogue for the planet Venus. It has one small moon: a captured asteroid called Gilly. It is especially notable for its extremely thick, dense atmosphere, which makes aerobraking and returning two of the most dangerous activities in the game. Additionally, Eve has the greatest surface gravity of all the planets, and the second highest escape velocity, second only to Jool. This makes it extremely hard to send missions there because of the Eve Effect.
A tutorial to get to Eve is available at the link.

In-game description

Topography

The surface of Eve seems to looks not unlike that of Saturn's largest moon, Titan. It has several oceans, among which lie large, flat continents. The terrain has a few mountain peaks but mostly consists of rolling hills that resemble purple sand dunes. These are speckled with small boulders, no doubt worn down by Eve's pressure, temperature, and winds. Eve's surface is covered with craters. Eve's highest mountain range has a peak of 7526 m.

Atmosphere

Temperature and pressure of Eve's atmosphere as a function of altitude.

(updated) Comparison of the atmospheres of Eve and Kerbin

Eve has an extremely dense atmosphere with a mass of approximately 1.9×10¹⁷ kilograms, a sea level pressure of 506.625 kilopascals (5 atmospheres), and a depth of 90,000 meters. Compared to the atmosphere of Kerbin, Eve's atmosphere has 4 times the mass and 5 times the sea level pressure. At an altitude of 14,579 m on Eve, the atmospheric pressure is the same as at sea level on Kerbin (1 atm). The pressure at the top of Eve's highest mountain peak is 2.4 atm.

The average molecular weight of Eve air is 43 g/mol, and its adiabatic index is 1.20. Although the composition of Eve's atmosphere is unknown these values suggest that it may consist largely of carbon dioxide. Another possibility is that the atmosphere is filled with ethane gas (C₂H₆, with a heat capacity of 1.2 and a molecular weight of 30 g/mol) and other compounds. If we assume LiquidFuel is kerosene, the joke that the lakes of Eve are LiquidFuel is strengthened by the purple colour since it is often mixed with a purple dye prior to sale. With a thick atmosphere filled with hydrocarbons, it is easy to imagine reactions that would yield compounds such as RP-1, the grade of kerosene used as rocket fuel. An atmosphere of 90% CO₂ and 10% C₂H₆ would have molecular weights and adiabatic indexes close to what is seen on Eve, though there are other combinations of gases that would work as well.

Like all other atmospheres in the game, Eve's atmosphere fades exponentially as altitude increases. The scale height varies with altitude, which is a change from pre-1.0 versions of the game. The pressure-altitude profile is globally constant and independent of temperature. The following table below gives the atmospheric pressure at various altitudes above sea level.

The surface of Eve is extremely hot, with a globally averaged sea level temperature of approximately 135 °C. Except for a small inversion layer between 50-60 km at low latitudes, air temperatures decrease with increasing altitude up to an altitude of 70 km. Above 70 km, the rarified atmosphere warms as altitude increases. Despite the hot surface temperatures, the lack of a stratosphere means that Eve's atmosphere is cooler than Kerbin's at altitudes above ≈26.5 km. The temperature rise above 70 km suggests the presence of a thermosphere in this area(70km to the Kármán line(90km)

Air temperatures vary with latitude and time of day. At the equator, sea level temperatures vary between a nighttime low of 147 °C and a daytime high of 156 °C. At the poles, the temperature varies between 87 °C and 95 °C. Since Eve has no axial tilt, there are no seasonal temperature variations.

From within Eve's atmosphere, the sky appears indigo during nighttime and a violet-purple color during the daytime. During dawn and dusk, the sky is green. The color of Eve's sky is likely due to wind-borne dust from Eve's purple surface, though it has also been suggested that iodine gas could be an atmospheric constituent.

Atmospheric flight

The thickness of Eve's atmosphere makes it well suited for aerocapture from a high-speed interplanetary intercept. The periapsis altitude required for a successful aerocapture depends on the spacecraft's drag characteristics, its approach velocity, and the desired apoapsis of the resulting orbit. The most effective periapsis for aerocapture is best determined experimentally; however, for a Hohmann transfer originating from Kerbin, it is found that the median value is about 62 km. Heat shields are required to prevent destructive overheating.

Parachutes work very effectively in Eve's dense atmosphere. A vehicle in Kerbin's atmosphere would require 3 times as much parachute area to attain the same descent rate on Eve.

Landing legs on Eve can easily break because of Eve's high gravity and, surprisingly enough, atmospheric pressure.

Because of Eve's high atmospheric pressure, rocket engines perform poorly at low altitudes. The engines best suited for low altitude use on Eve are the Aerospike, Vector, and Mammoth.

Jet engines do not function in Eve's atmosphere since it contains no oxygen — they make noise and consume fuel, but they produce no thrust. Planes with other propulsion methods do, however, work very well, and are a great way to explore the planet. They work best between 35 km and 25 km where the atmosphere generates enough lift to glide and steer, but not enough drag to slow the aircraft excessively.

Oceans

A large portion of Eve is covered in oceans of "Explodium",^[1] a liquid with a density of 1.5 tonnes per cubic metre^[2] that is heavily implied to be a form of rocket fuel. A real-world liquid that closely fits the properties of explodium is hydrogen peroxide (H₂O₂), which has a density of 1.450 tonnes per cubic metre and can be used as a monopropellant.

Eve is one of only three celestial bodies with oceans, alongside Kerbin and Laythe.

Biomes

Eve has 14 accesible Biomes with their own science to be collected, as well as one inaccesible Biome. Its main features are a large Explodium Sea with some scattered Islands and Shallow areas as well as a Main Continent and Poles. Within the Continent lie three large bodies of liquid, one being a Crater Lake. There are also areas covered with Impact Ejecta.

Biome list

Eve's biomes in KSP 1.12 (made with Scansat, hand-colored)

Eve In-game biome map as of 1.2

Poles Lowlands Midlands Highlands Foothills Peaks Impact Ejecta Craters (Inaccesible) Explodium Sea Akatsuki Lake Shallows Crater Lake Western Sea Olympus Eastern Sea

Missing and Buggy Biomes

In Kerbal Space Program, each biome has an RGB color assigned to it. To know in which biome a craft is, the game obtains the color of the biome from a Biome map (Seen above) and then referenced with the list of biomes.

Due to an oversight in the creation of Eve's biomes, the biome "Craters" is inaccesible, as it shares the same RGB value with the "Impact Ejecta" biome. Biome maps suggest that "Impact Ejecta" is supposed to surround the "Craters" biome, but due to the same RGB value, only "Impact Ejecta" can be recognized.

The biome "Akatsuki Lake" on the other hand, probably due to an oversight, is scattered in small pockets all around the planet, with it composing less than 0.001% of the surface of the planet. Most of these pockets are small areas located near the supposed-to-be "Craters" biome in the biome map (For example, you can find this biome at 0.08° S, 8.44° W). The "Akatsuki Lake" actually does exist in a large chunk on biome maps, as it is supposed to be the lake at 50 lat, 100 lng, but instead the lake's biome is "Foothills". This suggests that the developers forgot to add it in.

Natural satellites

Eve's only natural satellite is the tiny captured asteroid Gilly in a highly eccentric and inclined orbit. Gilly is the smallest celestial body in the Kerbol system and has the lowest surface gravity of any celestial body.

Orbital statistics

Visiting Eve potentially requires the least delta-v of any planet because its huge gravity well and dense atmosphere mitigate the difficulties that its slight relative inclination poses and greatly ease aero-captures, transfers, and landings; unfortunately, takeoff and escape therefore require the most delta-v of any celestial body with a solid surface.

The combination of high gravity and thick atmosphere makes return missions from the sea level of Eve very difficult. It requires about 7,000-7,500 m/s of delta-v to get into orbit from sea level. Driving to and launching from the peak of one of Eve's mountains can drastically reduce the amount of delta-V required (thus allowing successful launches with significantly lighter rockets). The highest peak on Eve since version 0.21.1 is 7540 m high, found near (25° S, 158.5° W)

A synchronous orbit of Eve requires an altitude of 10328.47 km and a velocity of 860.79 m/s. For a semi-synchronous orbit of ½ an Eve day (11.25 hours or 40500 seconds) an orbit of 6247.50 km above Eve is needed with a velocity of 1084.53 m/s.

Reference frames

Gallery

Kerbal Space Program

• 

  A topographic height map of Eve made with the ISA MapSat plugin. (Pre 0.18)

• 

  Eve landscape shot.

• 

  A Kerbal dropped from space.

• 

  Sunrises and sunsets on Eve can be really beautiful, with colors ranging from green to yellow to pink.

• 

  An unmanned plane in Eve's atmosphere.

• 

  A manned rover landing on the surface of Eve.

• 

  A large spacecraft aerobraking in Eve's upper atmosphere.

• 

  A probe on the surface of Eve at twilight

• 

  A Kerbal floating in front of a large interplanetary Eve ship.

• 

  Eve from over 10 million Kilometres.

• 

  An observation satellite around Eve.

Kerbal Space Program 2

• 

  The horizon of Eve in KSP2.

Bugs

• Eve has higher gravity than Kerbin, restricting a Kerbal's jump to only half a meter and making EVA jets useless. This being said, if a Kerbal falls from more than 4 m, they will hit the ground much harder than on Kerbin, which may cause a glitch to happen in which they will clip into the terrain and accelerate away from Eve at phenomenal speed, sometimes faster than the speed of light itself, usually sending the unlucky Kerbal on an escape trajectory from Kerbol if they are not killed by the fall. They may bring something into interstellar space with them if they hit an object instead of the ground.
• Solar panels will probably break off in flight, even with very low velocity. It's best to wait to extend them till stable on the surface, however, they can break on the surface of Eve even when retracted. This may be due to Eve's high gravity.
• Rovers can be challenging to drive on Eve due to its gravity, as the rover's wheels will easily break, but on the upside, since the gravity pulls them lower on their shocks and thus lower the centre of mass, they will be harder to flip over. Although not a glitch, it could cause clipping issues with a Kerbal sitting in EAS-1 External Command Seats

• When landing fast, a craft will sometimes sink into the surface of Eve. This can be fixed by using landing legs or engines to lift the ship up.

• When parachuting with a kerbal with warp on, it may be possible to start moving at 1% of the speed of light or more.

Changes

1.2

• Added biomes
• Redid Eve's pressure curve to smooth it out and remove errors.

0.90

• Added biomes

0.21

• Terrain Tweaks — more land mass to the surface

0.18

• Art pass.
• Terrain tweaks — the tallest points are now about 6 km in altitude, compared to 11 km before.

0.17

• Initial Release

Notes

1. ↑ The oceans are referred to as "Explodium Seas" by science experiments
2. ↑ As of 1.0.5, oceans now have explicit density values: Eve's oceans now have a density of 1.5 tonnes/m³ while water has a density of 1.0 tonnes/m³.

v t e Kerbol System Kerbol Moho Eve Kerbin Duna Dres Jool Eeloo (The Sun)   Gilly Mun Minmus Ike   Laythe Vall Tylo Bop Pol