If you don't mind me asking, who told you the Government hid an asteroid from us?
I say this because it was discovered October 9th, confirmed, estimated in size, it's trajectory calculated and by time we knew that much it's time to watch it hurtle across the sky and out of view.
For someone to have even suggested that this has been hidden from the public is absurd, and sounds like someone wants to jump onto each and every piece of news they find and mash it into their vision of how the world works - i.e. make stuff up with what little they know about the subject in the hope of convincing others with less information. A dirty tactic in anyone's book.
Linking this back to the initial spaceship claim, people have been anomaly hunting every source they can get their hands on for years. Where the rational amongst us see something unusual and investigate what it could actually be, the irrational jump to conclusions, conclusions which just happen to fit their beliefs… if you're alien hunting, every image anomaly you hunt down will somehow be involved and explained by how you think aliens work, rather than, say, how the camera wasn't working properly or whatever. Funny how that works.