The study calculated how large a hollow planetoid could be without collapsing in on itself, and the likelihood of a primordial black hole passing through an object on Earth. (If you're worried ...

The researchers suggest that large slabs of metal or ancient rock could serve as ... the researchers determined that any hollow object larger than a tenth of Earth’s size would likely collapse. Thus, ...

The large metal ball ... Though it's still unclear what exactly the object is, officials now believe it is hollow and cannot explode, according to the BBC and The Guardian. Police said the ...

The researchers suggest that large slabs of metal or ancient rock ... the researchers determined that any hollow object larger than a tenth of Earth’s size would likely collapse.