[Utah-astronomy] Can't quite figure this one

I have an optics question. A recent article mentioned how hard it would be to detect the tiny speck of light emitted by an exoplanet, because of the overwhelming brightness of the parent star. Fair enough. However, if a telescope in space were to use a tiny device to block the star's light, you'd think that would allow a view of the planet. -- I'm sure that's not right. But why isn't it? In space, isn't a star basically a point source? I would exepct no light scattering in what is essentially a vacuum. So what's wrong with that idea? Thanks, Joe