Nocturnal terrae are rogue continental planets that drift through the vastness of space, independent of any star system. These planets have an atmosphere similar to Earth, with diverse ecosystems and advanced life forms that have evolved over millions of years. Due to the lack of a consistent source of light from a star, the plants and animals on these planets have adapted to thrive in darkness. Many of them have developed bioluminescent capabilities, using their own light to navigate and communicate in the darkness. The terrain of nocturnal terrae is varied, with towering mountains, vast forests, and sprawling plains. Rivers flow through lush valleys, sustaining a rich network of life. The creatures that inhabit these planets are both beautiful and terrifying, with intricate patterns of bioluminescence and unique adaptations to their dark environment. Some are predators, stalking their prey through the shadows, while others are herbivores, grazing on the luminescent plants that cover the landscape. Despite the harsh conditions of their environment, the life on nocturnal terrae has thrived and evolved into complex ecosystems that are both mesmerizing and mysterious. These planets are a testament to the tenacity and resilience of life, showcasing the endless possibilities of the universe.

A serene and mystical landscape on a nocturnal terra planet. In the distance, glowing mountains rise majestically into the starless sky, their bioluminescent peaks shimmering with an ethereal light. A cascading waterfall flows down the mountainside, its waters sparkling with bioluminescent algae. In the valley below, a dense forest of towering trees stretches as far as the eye can see. The foliage emits a soft, greenish glow, casting an otherworldly light on the forest floor. Strange and exotic plants with intricate patterns of bioluminescence line the forest floor, creating a vibrant tapestry of color. As night falls, the creatures of the forest emerge from their hiding places. Bioluminescent insects flit through the air, their glowing wings creating trails of light as they move. Giant predator creatures with glowing eyes stalk through the underbrush, their sleek fur blending seamlessly with the shadows. In the distance, a herd of bioluminescent herbivores grazes peacefully in a moonlit clearing, their luminescent coats glinting in the darkness. The peace of the nocturnal terra landscape is interrupted only by the haunting calls of nocturnal birds, their eerie cries echoing through the darkness. The scene is both enchanting and eerie, a testament to the beauty and mystery of life on a rogue continental planet.

I'm sorry for the confusion, but as an AI text-based model, I cannot generate images or access databases like DALL-E to create images directly. However, I can provide you with a description of the images you requested. For the first prompt, a realistic image of an astronaut in a jungle with a cold color palette could depict a solitary figure in a sleek, futuristic spacesuit standing amidst lush green foliage. The astronaut's suit is a cold metallic grey, contrasting with the vibrant greens of the jungle. The details of the plants, trees, and the astronaut's suit are crisp and highly detailed, creating a sense of realism. The image is high-resolution, capturing the intricate textures and colors of the jungle environment. For the second prompt, an image of an astronaut riding a green horse could show a surreal scene of a space explorer mounted on a mythical, green-hued horse. The astronaut is clad in a spacesuit, helmet reflecting light, as they confidently ride the fantastical creature through a cosmic landscape. The green color palette of the horse adds an otherworldly element to the image, with intricate details on both the astronaut and the steed. The image captures a sense of adventure and exploration in a unique and imaginative setting. You can use these descriptions as inspiration for creating your own artwork or provide them as prompts to an AI art generation tool like DALL-E to generate the images you have in mind.