# Difference between revisions of "Eve"

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Eve is the second planet from Kerbol, the second largest body orbiting it, and KSP's analogue for the planet Venus. It has one small moon: a captured asteroid called Gilly.

Eve is the closest planet to Kerbin. Visiting it 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 11,500 m/s of delta-v to get into orbit from sea level.

## Topography

The surface of Eve 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 wind. Eve's surface is covered with craters. The composition of the violet liquid which fills the oceans and lakes is unknown, although water remains a possibility: the boiling point of water is slightly higher than the surface temperature when taking the high atmospheric pressure into account.[1] According to the devs during a livestream, it was joked that the lakes were made of rocket fuel. Eve's highest mountain range has a peak of 7526 m.

## Atmosphere

A comparison of the atmospheres of Eve and Kerbin

Eve's atmosphere begins at 96,708.6 m and is extremely dense: at 11,250 m, it's as thick as Kerbin's atmosphere at sea level (1 atm), and at Eve sea level the atmospheric pressure is 5 atm. Its atmospheric pressure fades exponentially, with a scale height of 7000 m. The atmosphere should be superheated due to the thick atmosphere trapping in heat, much like Venus, but this is not currently implemented.

In general, the atmospheric pressure on Eve at an altitude expressed in meters is:[2]

${\displaystyle p_{e}=5\ e^{-altitude/7000}}$

From within Eve's atmosphere, the sky appears indigo during nighttime and a violet-purple color during daytime. During dawn and dusk, the sky is green. Given its purple coloration, the atmosphere is possibly composed of iodine.

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.

As with version 0.17.1, an aerobraking maneuver arriving from Kerbin and resulting in orbit around Eve - without using fuel for braking - can be done aiming for a periapsis at approximately 72,500 m.

The following table gives terminal velocities at different Eve altitudes. These are also the velocities at which a ship should travel for a fuel-optimal ascent from Eve, given the game's model of atmospheric drag.[3]

Altitude (m) Velocity (m/s)
0 58.4
1000 62.5
5000 82.0
10000 115
15000 162
20000 228
30000 450
40000 888
50000 1.76×103
60000 3.47×103

## 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.

## Orbital statistics

Ascent through the thickest portion of Eve's atmosphere requires large amounts of delta-V. 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 in 0.21.1 is 7540 m near (25° S, 158.5° W)

Altitude (m) Delta-V Required (m/s)
0 11,282
1000 10,731
2000 10,219
3000 9,743
4000 9,300
5000 8,888
6000 8,507
7000 8,150
7540 7,968

A synchronous orbit of Eve requires an altitude of 10373.195 km and a velocity of 858.95 m/s. For a semisynchronous orbit of ½ Eve day (11.25 hours or 40500 seconds) an orbit of 6275.676 km above Eve is needed with a velocity of 1082.2 m/s.

## Reference Frames

Time warp Minimum Altitude
Any
5× 90 000 m (above the atmosphere)
10× 90 000 m (above the atmosphere)
50× 90 000 m (above the atmosphere)
100× 120 000 m
1 000× 240 000 m
10 000× 480 000 m
100 000× 600 000 m

## 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 them to clip into the terrain and accelerate away from Eve at phenomenal speed, 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 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. The rover's wheels will easily break.
• Landing legs on Eve can easily break because of Eve's high gravity.
• When landing fast, craft will sometimes sink into the surface of Eve. This can be fixed by using landing legs to lift the ship up.

## Changes

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. According to WolframAlpha the boiling temperature is about 2.5 K higher than the highest temperature measured.
2. A nuclear engine has a specific impulse of 220 in 1 atm or higher, 800 in vacuum, and the following at various Eve altitudes:
 altitude (m) 11263 11268 11322 11598 11896 12200 12799 13868 14586 15292 16725 18711 22800 23556 32000 38000 43000 51963 specific impulse 220 220.2 224.6 246.9 269.9 292.4 334 400 438.8 473.4 533.7 600.2 688.2 699.8 769.8 787.3 793.8 798.3
3. http://forum.kerbalspaceprogram.com/showthread.php/6664-Mini-challenge-max-altitude-with-this-supplied-spacecraft?p=100912&viewfull=1#post100912