[Larry Lucido]

but if it is coming right towards us it does not move- we can only tell it is coming by it growing brighter.

Is there any equivalent of doppler-radar that can detect the speed of a seemingly stationary object headed toward the earth?

[Mr. K]

I'm not certain, but thats a pretty good question- it is an awful big sky and sending a signal and hearing a response may be a way to detect something like that.

The response would travel at the speed of light so we might now get responses for hours (or days) and the reflection may be pretty weak.

[1ofmanyfree]

Los Alamos is working on it...