Rohatsu, or Bodhi Day, marks the day in 596 BCE, when the Buddha achieved enlightenment in Bodh Gaya, India. After leaving his family and possessions behind at age 29, he sought to discover the meaning of life, particularly the reasons for its hardships. He sat under a pipal tree and vowed that he would remain there till he found what he was seeking. On the morning of the eighth day, he realized that humans suffer because of ignorance. But ignorance can be overcome through the Eightfold Path he went on to elucidate. This day is generally regarded as the birth day of Buddhism. We celebrate the point in time when the Buddha achieved enlightenment and escaped the endless cycle of birth, death, and rebirth.
The Buddha was enlightened...when he looked up at the morning star, the planet we call Venus.

The brightness of this planet was seen by Buddha from the depths of one week of
samadhi [deep awareness]. The Buddha received that brightness with the same eyes of
zazen [sitting meditation] that enable us to realize perfect enlightenment.
One week straight of this deepest possible
samadhi was burst through by the brilliance of that morning star. A whole week's experience of that world burst the brightness of the morning star, plunging into the Buddha's eyes and giving rebirth to the Buddha's consciousness.
He cried: "That's it! That's it! That's it. That's me! That's me that's shining so brilliantly!"
Top photo: Heidi Utz
Middle photo: NASA
Bottom excerpt from "Morning Dewdrops of the Mind: Teachings of a Contemporary Zen Master," by Roy Tribelhorn and Shodo Harada Roshi