Cyanobacteria or simply known as blue-green algae may have formed the oxygen into the early atmosphere. This is because these micro-organism has the capability to photosynthesize wherein they can produce oxygen and carbohydrates. In fact, all the plants contribute in the fomation of oxygen.
Answer:
space
Explanation:
they figured it out going to space and since a star is a small peice of the sun they can't touch it it's impossible without getting heat burns or dying so they ither observe a star using a telescope or went to space for days
Answer:
oxygen te digo por qué ya Ise esa bro