There are a few planets in the solar system that can support life, I think aliens know this and travel from planet to planet studying and gathering specimens, learning, etc. So the question is shat do we have to offer them that they already know about us. What is the need for them to contact us. We are dealing with a highly sofisticated race. We only want to contact them so we can understand them and take whatever we can get from them all their knowledge and technology, kill a few so we can understand how they work. Yes we yearn for contact for our own selfish reasons. The only thing we can teach them is how to destroy a planet like ours with global warming, or exploitation of natural resources or pollution, etc. We as a species have nothing to offer aliens. Scientist want to find and travel to distant planets like ours not only to find new life and prove we are not alone, but to find another earth so we can move there cause we made such a mess of this planet, but being human we will make the same mistakes again, the greedy will always be greedy and future generations will most probably do the same thing again like we are doing. The best thing that could happen is the aliens exterminating humans from this planet,in the scheme of things we serve no purpose, except to take and take without remorse. We are a plague on the planet.