We are not alone in the Universe. However, we are to date, the only human beings known. That is far from being alone, however. Life creates life where ever the circumstances, materials and energy are present. Earthlings know this from searching frozen Antarctica and deep within the crust and oceans of our own planet.
SETI, the Search for Extra terrestrial Intelligence is just one small set of searchers who have been exploring the known neighborhood for at least one million years.
We know from the water traces of planets within our own solar system, and on their moons, that there was every probability for life to have come and gone more than once, even in our teensy little solar system. It has happened billions of times on earth, in millions of ages. With so much space and time in the cosmos, it seems hubris to even imagine we are the only ones. They may not look human, or even be attracted to Captain Kirk, but that does not mean they do not exist.
Finding others out there would be a great advancement for earth because human beings seek belonging. The late great Carl Sagan knew this, and it is the premise for his science fiction novel, Contact. Human beings evolved in complete inter-dependence with other organisms, and need belonging to thrive. However, doubt and even faith, can obscure our goals. Other organisms and systems allow all life and bio-diversity to flourish.
Knowing the fragility and yet resilience of life is life affirming to homo sapiens. Here is why: It is obvious that human beings need nature, food, water, soil, and air quality to be sustainable. Yet, psychologically, there are those who do not recognize our very deep emotional, mental, and spiritual connection to planet earth. Seeing it from another perspective is useful.
Our best selves have been lost somewhere since Industrial revolution which moved us indoors. And spirituality changed from earth centric to language centric, and into dogma. All improvements and developments became described in ways that elevated humanity over earth. World conquest and domination seemed like a good idea at the time. Man could then define himself as the brightest one, with the most innovation, mechanical aptitude, language and sacred divinity. The problem of course, is that man denied He needs nature and natural laws.
We lost our "honored" place as the center of the Universe a long time ago. Then Darwin also showed that we are just as others on our planet, animals that live, suffer, laugh and die. Yet, our connection Psychology was further obscured by a very dualistic perspective of earth that called for religions and the powerful, to cast human beings as masters, or conquerors of the planet, rather than kin to our world. Unless human nature changes drastically, humans will fear or dread others. Or worse, if history is repeated other life forms will be exploited, conquered and/or annihilated. Or, as Stephen Hawking suggested, we could be the vanquished ones.
Respecting life, all life, and sustaining it seeks to reverse the mindset that we are here to take all we can, as quickly as we can, before the “enemy” forces take it first. It identifies our focus on conflict and differences as damaging. It allows that people see they need one another, and that all of nature includes supporting organisms. Hopefully then our need to belong, and their need to connect will allow our first real contact to be benevolent.