One of NASA’s current goals for its human spaceflight program is to put people on the surface of an asteroid by the middle of the next decade. That mission would take a new generation of rocket, a new crew capsule and would subject astronauts to the hazards of the longest duration spaceflights outside of the protection of Earth’s atmosphere ever attempted. Popular Science:

manned mission beyond the moon to a faraway asteroid would likely take six months or more to reach even the closest passing asteroid of interest. During that time out from under the protective umbrella of Earth’s magnetic field, astronauts would be exposed to long periods of cosmic radiation–the effects of which aren’t exactly defined.

So if taking people to an asteroid is expensive and risky, might it not be easier to, say, bring the asteroid to us? That is the idea outlined by NASA’s Keck Institute for Space Studies. The scientists imagine shooting a rocket off to a faraway asteroid and tugging the asteroid into orbit around the Moon. An asteroid circling the Moon is much more accessible than one six months off, and the hazards are a little bit more well known. A blog post by Phys.org reads:

In their paper, the Keck team proposes using an Atlas V rocket to launch a craft that once in space would be slow moving, powered by solar heated ions. Once the target is reached, a bag would be opened that would engulf the asteroid – which would likely be no bigger than 7 meters wide – then drag it back and place it into orbit around the moon.

The asteroid catch-and-release, says New Scientist, wouldn’t be possible for a while—not until the 2020s—and the mission itself would take from six to ten years to carry out.

Though bringing an asteroid to the Moon would certainly make the asteroid-studying aspect of the mission much simpler, President Obama originally outlined the asteroid visit as a stepping stone to putting people on the surface of Mars, says Space.com. While the proposition may solve a number of problems, it could also be seen as a case of missing the forest for the trees.

More from Smithsonian.com:

Don Quijote May Tilt at an Asteroid

Giant Paintball Gun Could Save the World From Death-by-Asteroid

To the Asteroids and Beyond