Over in D&D 3.5e Races of Stone gives us the feat “Fling Ally” for the fans of the Fastball Special, which lets you hurl an ally smaller than you as though that ally was a ranged weapon with an incredibly terrible range.
The Epic Level Hand book has Distant Shot, an epic level feat that lets you perform the epic level task of throwing or firing a ranged weapon against any target within line of sight.
On a clear night, you should have line of sight to the moon. With magical protection and maybe someone who doesn’t need to breathe like a construct, undead, or adventurer with the right equipment, an epic-level fighter can start the space program. Given that the projectile hits the target within a round (six seconds), the fighter is throwing things at some significant percentage of the speed of light.
Except, well… the problem with line of sight is that checks made to Spot something take a -1 penalty per 10 feet of distance. Given that our moon is somewhere around 1.2 to 1.3 billion feet away, you’re looking at a 120 million penalty to your check.
But wait, the moon is pretty big. Things take a penalty to their checks to hide based on how big they are. The Tarrasque, as a 50 foot tall killing machine, takes a -16 penalty to its checks to hide (and thus is incredibly difficult for your average commoner to spot if it’s standing on the other end of a football field). The epic rules have options for creatures larger than colossal, which basically dictate that every time its size doubles, it moves up another category. 64 feet (2^6) is the bottom for Colossal, providing a (-8) 2^3 size penalty. The moon is 2159 miles wide, roughly 11.4 million feet. 8.3 million feet is around 2^23, which means the moon is somewhere around Colossal+17, and takes a 2^20 size penalty, multiplied by 4 to offset your spot check (2^22, or roughly 4 million).
You take a -120 million penalty to spot the moon, offset by a 4 million bonus because the moon is big. Unless I screwed up by a factor of 64, you probably can’t see the moon.
The sun is roughly 400 times larger, but also roughly 400 times farther away, so no luck there. Other stars may range from the sun’s size to 1500 times larger, but they’re also 250,000 times farther away at minimum.
The skies above Greyhawk are black and empty. None have ever seen the stars."