Why space exploration might be completely irresponsible and possibly dangerous for the human race

Ok, first pretend that there were no sea creatures on the planet, since we can not survive in water, we could never imagine anything could, the same goes for space, we cant imagine anything evolving and living in space because we cant but there could be, imagine something that that evolved in space and think about how much room there is in space for something to grow...imagine how big it could get. we are the size we are because of how much room we had to grow. imagine a squid like creature the size of 50 suns and we alert it to earths location or come across it in space. it wouldnt even have to want to get us, it could just be curious and accidently destroy us in its approach, Ok that was the dangerous part, the irresponsible part would be imagine a planet the size of a peanut with a full poppulation of a tiny seven billion people just like us and one of our space ships completely destroys it without noticing....se what im getting at?