Astronaut at a Golden Portal Above Cyberpunk City

A cinematic digital art piece depicting a lone astronaut in a sleek black suit with blue glowing accents, standing on a futuristic metallic catwalk. The astronaut faces a massive, radiant golden portal or holographic planetary map made of intricate energy rings and digital data displays. The scene is set high above a sprawling cyberpunk city at night, with countless glowing skyscrapers stretching to the horizon. The background features a deep space sky filled with a nebula, distant stars, and a crescent moon. The composition is symmetrical and framed by a large circular structural opening, creating a sense of awe, discovery, and high-tech wonder. The lighting is a dramatic contrast between the warm golden glow of the portal and the cool blue neon lights of the city and suit.