A large star is seen in the sky with a bright blue streak

"Comets are often called the 'dirty snowballs' of space, due to its icy and dusty composition. They are mainly composed of water, carbon dioxide, ammonia and other frozen volatile materials. The most striking feature of comets is their bright tail, which forms as they approach the Sun. Quando um cometa se aproxima do Sol, o calor solar faz com que os materiais congelados se sublimem, releasing dust and gases that form a tail that always points in the opposite direction to the Sun. This tail is what makes comets visible from Earth." (Arte digital realista) (qualidade extrema), (HDR+)