Our home star, the sun, is a middle-aged main sequence star. That is to say, it is roughly halfway through its lifecycle and is an average-sized star compared to the spectrum of stellar types that can be found elsewhere in our galaxy and beyond.
Life, in its 4.5 billion-year journey on Earth, has had an intimate relationship with the sun. It provides life with its main source of energy via photosynthesis, it keeps temperatures within a balmy range, and its energy drives many of Earth's cycles on which the rhythms of life are coupled to. Our planet's habitable conditions are in large part due to the type of star the sun is and its relative age.
There are, of course, a number of stars in the cosmos, each with different characteristics that will affect the conditions on any planets they may possess. Planetary scientists, as they search for habitable conditions on worlds other than our own, have to consider how different types of stars might alter the conditions for habitability on planets of interest.
So, let's explore why the relationship between a planet and its star is crucial to understanding whether a planet may have conditions that could support life like our own.
