[WP] As it turns out, Earth being a deathworld doesn't make us too OP for aliens to not compete with us. Instead, it just makes invading us total hell. Earth is space 'Nam!
Why did the scouting force suffer crippling losses and need to retreat before being able to establish a base of operations of the plant?
Even before we talk about the planets’ fauna and flora, we must make a mention of the planet itself.
A nauseating continuously active magnetic field permeates this active metal core planet, making any surface operation difficult for our operatives. This metal core is so dense as to skew the expected surface gravity. This follows on with the dense oxygen rich atmosphere of this high gravity world which presents a substantial set of issues. Atmospheric entry is highly exothermic due to the density, requiring a substantial shielding on our surface delivery vessels. Then the high surface gravity is too substantial for our thrusters to compensate, requiring chemical fuels to be used for deceleration and landing. The high free oxygen content of the atmosphere at ground level reacts quickly, oxidising metals and igniting fires in any unshielded components. There is really no scientific explanation as to why this planet has such a high atmospheric content of Oxygen.
Once landed, due to the use of chemical fuels, a refuelling process must be completed before our surface delivery vessels can be returned to the safety of orbit and during this time they are vulnerable to oxydation and damages caused by fauna.
Furthermore, the oxygen layer blocks most of the ultraviolet radiation from reaching the surface of the planet making our visual sensing equipment practically unusable, forcing us to calibrate to alternative wavelengths of light.
With these initial obstacles mitigated, we must talk about the microbial and viral load of this planet. This planet is covered in dangerous unicellular and smaller than unicellular weapons of mass destruction which are fighting a continuous endless battle. The first sensor probes detected hundreds of harmful protein chemicals in the soil around the landers. Therefore it is necessary to maintain continuous biological isolation from the atmosphere.
Hard suits are necessary here due to the gravity and surface atmospheric pressure which crush our normal enviro-suits. Our operatives, even supported by hard suits, suffer the continuous strain of the high g load on their circulatory system. It seems that the local multicellular fauna has adapted to these conditions by creating internal structural elements out of calcium to resist the g forces, as well as a powerful single pump to support their circulatory system. This is such a departure from our advanced continuous pulse circulatory system that our scientists are baffled.
The dominant fauna of the planet is highly adapted to these conditions and seems to efficiently metabolise oxygen through a process yet to be understood, providing them with exceptional energy to weight ratio. Additionally, this fauna - similarly to the unicellulars - is continuously engaged in warfare. Although the technology is primitive, it is efficient and most of all, it is widespread among their numbers. In contrast to our operatives which only come from the warriors caste, it seems they have an undifferentiated common species.
Due to all these factors, and while we could initiate a sterilisation process from orbit, it has been decided to leave this planet as is. The high g and dense atmosphere means that for our purposes, the planet is nearly unusable and there exists many asteroids in the system that are far easier to process for raw materials. A small monitoring station will be established on the single moon of that planet to warn us in case the local fauna develops sufficient technological advancement to escape the gravity well.