For instance, the eyeing of small and or dim near Earth objects by ground-based telescopes is significantly limited due to atmospheric turbulence; geographic limitations of telescope location; Earth’s day/night cycle; poor weather; and our celestial buddy -- the Moon -- getting in the way.

Warning times for long period comets might be on the order of weeks or months. Only 10 percent of known long period comets have been discovered more than 100 days before swinging by the Sun. For those pesky smaller asteroids, potentially no warning time is available if they have not been catalogued.

The CAPS assessment gives high marks to space-based systems. Detection hardware could be placed in Earth orbit; at the Lagrange points, nominally at one AU from Earth; even on the Moon’s surface. CAPS might also make use of existing and future ground-based assets like the Large-Aperture Synoptic Survey Telescope.

Of course, even with far-flung space-based gear, there’s also a drawback. The placement of CAPS in space is more doable given a "down-range future", one in which space has become a beehive of activity. That means a busy space station, lots of reusable in-space transportation, command and data handling services, lunar gateways, and crew and cargo transfer vehicles flying about here and there.

The placement and tending of CAPS is greatly influenced by synergistic use of a growing space infrastructure. "That’s a big issue. Maintaining, servicing, and upgrading CAPS depends on what your vision is for the next 40 years," he said.

Nearly 30 years has passed since the last Apollo mission in 1972. Along with its passing, so too did hope of planting a permanent presence on the Moon. That may change in the future, Mazanek said, and regular sortie flights to neighboring Luna could give you the ability build and upgrade Moon-based CAPS hardware.

"I think there’s a lot of strong arguments for the Moon being a very ideal astronomical location for these type of observations. It has a natural, 28-day rotation period to see the celestial sphere," Mazanek said. On the Moon there are craters deep enough that they are occulted from the sunlight continuously. That’s a perfect locale for plopping down a telescope system, he said.

"If you have CAPS on the Moon, your only real worry is power, as long as you can protect equipment against the lunar environment," Mazanek explained. There’s also ready-made poetic justice on the Moon, he added. That is, outfitting a lunar impact crater with devices to thwart future impactors.

"There’s a host of good reasons to go back to the Moon. In my opinion, this might be another good reason," the Langley study leader said.

Part of the CAPS evaluation is to investigate "revolutionary" technologies and techniques that can mitigate potentially hazardous near Earth objects. Mazanek calls it "orbit modification." Thinking of ways to protect the Earth from an impactor is a study goal, and an aspect of the Langley’s RASC-supported work, he said.

How do you control the orbits of these objects, both from a protection standpoint and from an exploitation standpoint? Mining or making use of asteroids and comets for other needs is not too far-fetched of an idea, Mazanek said.

"There’s a huge amount of natural resources available in these objects. If we ever do go out and colonize the solar system, it’s pretty obvious that we’re probably going to use resources available in space and not bring everything from Earth," Mazanek pointed out. "We have to come up with ways to live off the land."

Lastly, having a stockpile of small asteroids at the ready -- objects that are under your orbital control -- might prove critically important.

"There may come an object that’s so large you can’t deflect it. You could use your stockpile of small objects as a mechanism to fight the larger one," Mazanek. "It is like a game of cosmic billiards, being able to use smaller objects to deflect larger ones. There’s an irony there that has a lot of appeal."