Eclipse is the phenomenon that one object hides another object or enters that shadow. ‘a solar eclipse’ is the moon’s phenomenon covering the sun.
When the moon enters the shadow of the earth, it becomes ‘the lunar eclipse.’
Transit of Venus
Venus passes between the Sun and Earth. As Venus passes in front of the sun, Venus appears as a small black dot, and the sun’s radiation is slightly reduced. This very small reduction in solar radiation can be used to detect something passing between the sun and the earth. We use this principle to look for planets that resemble Earth while observing celestial bodies outside the solar system.