Scientists studied several scenarios where earth might encounter extraterrestrial life, with the most alarming potential outcome being the total destruction of the planet to stave off humans polluting the rest of the galaxy.

Beyond endangering fellow-man, humans may pose a serious threat to the entire galaxy, according to a paper written by a trio of scientists dated in April and published in the journal Acta Astronautica.

A preemptive strike would be particularly likely in the early phases of our expansion because a civilization may become increasingly difficult to destroy as it continues to expand, the study says.

Humanity may just now be entering the period in which its rapid civilizational expansion could be detected by an ETI (extraterrestrial intelligence) because our expansion is changing the composition of the Earth's atmosphere, via greenhouse gas emissions.

The author suggests limiting growth and reduce our impact on global ecosystems.

It would be particularly important for us to limit our emissions of greenhouse gases, since atmospheric composition can be observed from other planets, stated the authors. It would also be prudent to limit the communication of the destruction of our planet to the outside, they said, as to not provoke any extraterrestrial life.

At the heart of these scenarios is the possibility that intrinsic value may be more efficiently produced in our absence, the researchers write.

This is just one of several outcomes if earth were to encounter intelligent life, thankfully. Possible outcomes ranges from beneficial to harmful, according to the paper by Seth Baum, a doctoral candidate, and Jacob Haqq-Misra and Shawn Domagal-Goldman, both postdoctoral scholars.

Contact with extraterrestrials might lead to a discussion of math and science or helpful collaboration on solving serious issues like world hunger or poverty, the paper said. Aliens could also help man-kind advance as they share advanced technologies, and help man reach for the stars.

The other author, Domagal-Goldman, said in a blog post on Friday that while he believed contact with alien civilization was unlikely, researching the possibility was fun.

While there is still no detected form of extraterrestrial intelligence, the researchers said their review provided the groundwork for a more comprehensive plan to respond to alien contact should it ever occur.