According to a recent talk given at UCSB, the largest known black holes have a Schwarzschild radius of the same order of magnitude as the radius of the Earth's orbit -- i.e., 1 AU. Light would orbit this black hole in a few minutes; I would presume that an Earth-sized object would have to orbit at nearly the speed of light even at 5 AU (Jupiter's distance from the Sun). At 12:17 PM 10/20/2013, Whitfield Diffie wrote:

...

You could survive a fall through the event horizon of a quiescent galactic-mass black hole. (Of course you wouldn't survive for long after that, as you approached the singularity.

I don't see why. If a black hole is massive enough, (my crude calculation, which those with better ALUs are welcome to correct, is 3.65x10^18 solar masses or about four million times the mass of the Miky Way galaxy) it has about the density of our galaxy as a whole and might be habitable.

...

Nor could you avoid the singularity.)

Why couldn't you be in orbit inside the event horizon.

What this leads to is the question can the universe be distinguished from a black hole?

Whit