Create a minimalist logo for "MegaMartBR" with a theme of a single planet, using only blue and white tones. Incorporate the planet to symbolize global reach and connectivity, and include a simple shopping cart to emphasize the e-commerce aspect. Add a constellation surrounding the planet to enhance the theme. Include subtle background effects, such as stars or a gradient, to add depth and visual interest. Focus on creating a clean, straightforward design that is versatile and easily recognizable across different sizes and formats, with an emphasis on simplicity and clarity. No text should be included in the logo.