If bitcoin algorithm was broken and some one started spitting out blocks one after the other through their other worldly space computer, could it be detected that the same miner was busting all the blocks?

Not necessarily. There's not enough data recorded to conclusively show that the same person is behind the new blocks, but people would figure it out: The block generation rate and network difficulty would shoot up without anyone knowing why. People could try to trace where the mined bitcoins are first seen and where they go. And you could trace the first IPs known to report the blocks: if your interplanetary computer always communicates over one IP, it might get noticed as something that has a lot of power behind it (be that a pool, supercomputer, etc.).

If that happened, the value of Bitcoin would probably drop as people realize that we'd be vulnerable to a 51% attack at the hands of an unknown party.

Follow up question: How does the network strength or hashing power get computed? By just assuming the required H/s for the current technology?

The difficulty is known (since it's calculated based on all the previous blocks), and the block generation rate is known (since you can look at how often blocks are coming in). From these, it's easy to estimate the network's total hashing power.

It's like having a lot of people throwing weighted coins (such that 1 millionth of the time it comes up heads) and telling you when they hit a heads. If one such "heads" is reported every 10 minutes (600 seconds), you can make a very accurate estimation of how many times per second the coins are being flipped. In this example:

(1,000,000 flips/heads) / (600 seconds/heads) ~= 
1,667 flips/second

The network difficulty is how you adjust this 1,000,000 figure so that the 600 figure stays consistent as the network's total hash power (1,667) changes.