Zenith, the point in the heavens that is directly above the head of the observer. The opposite point, that directly below the observer's feet, is the nadir. Zenith also applies to the highest point a heavenly body appears to reach above the horizon. The sun reaches its zenith at noon.
We take much for granted about our universe, like it's getting bigger. What if the universe stopped expanding and started collapsing inward with a giant crunch?
There's a 45-million-ton asteroid out there with Earth's name on it. In 2029, it'll be closer to us than our moon is. And that's not even the fly-by that scientists are worried about.