Answer:
Depends
Explanation:
Is your topic general space, stars, the planets, or space phenomenon?
If it's general space, try writing about different feats humanity has made in space exploration. For example, why not write about how America was the first country to put a man in the moon?
If it's the stars, chose a star and write about. For example, there's Sirius, the brightest star in the night sky.
If it's about the planets, chose a planet and write about it, and it's ecosystem. For example, Venus, Earth's sister planet, is the hottest planet in our solar system despite not actually being the planet closest to the Sun, because it's sulfur cloud atmosphere traps and mutliplys heat, (like a hyper greenhouse gas effect).
If it's about space phenomenon, try writing about rare instances in space, such as comets, or asteroids. For example, Hailey's Comet is a comet that passes Earth once every 70 years.