Scientists are searching for planets that are similar to Earth because when resources are used up, we can resort to another planet. Whether it be to travel to live at a different planet or to collect resources from there, either option would be nice for a last resort.
The kind of poem reading that the lines above represent is literal reading. There are no figures of speech here, such as metaphors, personifications, etc. which is why it's not a symbolic, figurative, or analytical reading. There is nothing to analyze here - the lines just tell the story of an eagle searching for its prey - it can't get any more literal than that.
