A Penn State engineer believes autonomous, self-replicating exobots will ultimately be tasked with exploring the universe.
"The basic premise is that human space exploration must be highly efficient, cost effective, and autonomous as placing humans beyond low Earth orbit is fraught with political economic, and technical difficulties," explained Professor John D. Mathews.
"If aliens are out there, they have the same problems we do, they need to conserve resources, are limited by the laws of physics and they may not even be eager to meet us."
According to Mathews, only by developing and deploying self-replicating robotic spacecraft can the human race efficiently explore the vast reaches of the Kuiper Belt, Oort Cloud and beyond.
Indeed, the Penn State engineer assumes that any extraterrestrial would need to follow a similar path to the stars - sending robots rather than living beings - which would explain why SETI has not succeeded to date.
"If they are like us, they too have a dysfunctional government and all the other problems plaguing us. They won't want to spend a lot to communicate with us," he said.
"It is extremely difficult to broadcast into the galaxy and requires vast resources. Radio signals need to emanate in every direction to fill the sky, and the energy requirement to broadcast throughout space is quite high."
To minimize the cost of robotic explorers, Mathews suggests an initial production run of 'bots manufactured on the moon to take advantage of the resources and the one-sixth gravity.
"We have the technology to [build] these exobots now, except for a compact power source. To create a network of autonomous robots capable of passing information to each other and back to earth, the vehicles must be able to identify their exact location and determine the time," he noted.
"With these two bits of knowledge, they should be able to determine where all the other robots near them are and target them with an infrared laser beam carrying data."
Initially, the exobots could serve two purposes: clear existing debris and monitor the more than 1,200 near Earth asteroids that are particularly hazardous in that they closely approach Earth during their orbits.
Ultimately, the network of exobots - self-replicating, autonomous and capable of learning - will spread through the solar system and into the galaxy, using the resources they find there to continue their mission. Communicating with infrared lasers is communicating at the speed of light, which is the fastest we can hope to achieve.
"Our assumption in the search for extraterrestrial intelligence is that ET wants to be found. But who has energy resources to spend trying to wave their metaphorical hand across the galaxy?" Mathews asked rhetorically.
"It is more likely that one of our exobots will intercept a signal from one of theirs if we are to make first contact."