35 kilometers

Mesosphere: The mesosphere is the coldest layer, dropping to as low as -184 degrees Fahrenheit. The temperature decreases with height in this layer. Most meteors vaporize in the mesosphere.

about 319 miles

Venus is so hot because it is surrounded by a very thick atmosphere which is about 100 times more massive than our atmosphere here on Earth. As sunlight passes through the atmosphere, it heats up the surface of Venus.

GN-z11 is the youngest and most distant galaxy scientists have observed. This video zooms to its location, some 32 billion light-years away. GN-z11 is 13.4 billion years old and formed 400 million years after the Big Bang. Its irregular shape is typical for galaxies of that time period.

The stock answer that most smartphone companies will give you is 2-3 years. That goes for iPhones, Androids, or any of the other varieties of devices that are on the market. The reason that’s the most common response is that toward the end of its usable life, a smartphone will begin to slow down.

Can a Black Hole Destroy Earth? Earth is facing no threat because no black hole is close enough to the solar system for our planet. According to NASA, even if a black hole the same mass as the sun replace the sun, Earth still would not fall in.

The Earth’s Schwarzschild radius is thought to be around 8.7mm, or roughly 17.5mm in diameter. A U.S. cent is around 19mm in diameter, so if someone were to shrink the Earth down to a little less than the size of a U.S. cent, it would become a black hole.

The logical paradox has given researchers a headache, in part because according to Einstein’s theory of general relativity, “closed timelike curves” are possible, theoretically allowing an observer to travel back in time and interact with their past self — potentially endangering their own existence.