What is on operrata?

What is the center of the Earth known as? Does Ramadan end on a full moon day? Stars and galaxies that start with Y? What day was it on the 12th April 1974? When were umbrellas invented? What day were the solar panels invented? Name the process that causes a star to begin producing vast amounts of energy? If the sun is facing us is Australia on the opposite side? What is a pneumonic device to help remember the planets? Can a person be hypnotised while sleeping? What day of the week did April 18 1968 fall on? Did the bodies of the space shuttle challenger disaster recovered? When a light source is moving away from an observer the wavelength appears? Why does the position of the oceans ellipse change over the course of a given week? The length of daylight on the moon is about? What does 2ttr mean? Is Milky Way proper or common noun? How is solar energy cheap? Why did Japanese nobles in the city of heian call themselves ''dwellers among the clouds? What decides what cloud will form?