Answer : 1. "It is a term used to describe the position of planets in the solar system."
Explanation :

Next month, on June 3, six planets – Mercury, Mars, Jupiter, Saturn, Uranus and Neptune – will be aligned in the sky. This alignment, an optical illusion of perspective, will be visible from Earth. Mars and Saturn will be visible to the naked eye, although faintly, while Uranus and Neptune will require a telescope. Mercury and Jupiter will be difficult to see because of their proximity to the Sun.