Studies conducted over the timer showed that life on Earth evolved in bodies of water from the organic materials remaining from the solar system’s birth cloud. This matter, initially simple molecules, developed into complex molecules and eventually became living material. Our host star had its involvement in this process, and life on exoplanets needs a Sun like ours to develop.
So far, the scientists are basing the search for extraterrestrial life forms on similar organic materials to what our Earth held billions of years ago. That, undoubtedly, until we’ll going to find a new kind of life that doesn’t rely on the same molecules. Well, accordingly, transiting from simple molecules to more complex ones that could give birth to life is a long process, and astronomers think that life on exoplanets can only emerge if these space objects orbit a red dwarf like our Sun.
A Sun like ours could help life on exoplanets emerge, but it’s not sufficient
When the life was born on Earth, about 3.5 billion years ago, our planet was already warm enough to sustain liquid water. In fact, excepting some periods of climate change, such as the Ice Ages, the Earth was quite constant regarding its temperatures. And that allowed the plants to develop, which sucked up the remaining greenhouse gases and released oxygen.
But, all these would not have been possible without our Sun, a red dwarf with constant energy output and limited UV radiations, and our planet’s magnetic field. Based on the numerous studies that proved that our host star favored the emergence of life on Earth, the astronomers believe that life on exoplanets needs a red dwarf host star, similar to ours, to evolve.
On the other hand, hot, blue stars, for example, are not the best candidates for bearing living exoplanets since these suns do not favor the transition from simple molecules to complex molecules, and then to life, because they are too hot and send high levels of UV radiations.