There may be 2 trillion galaxies in the observable universe, although that number has recently been estimated at only several hundred billion based on new data from New Horizons. Assuming the universe ...

Biggest vs smallest—how do we measure up in the grand scheme of the universe? Explore the fascinating scales of existence, ...

Light is a time machine: all we see, from stars to galaxies, shows the past. Expanding space stretches light, letting ...

Determine an appropriate scale, depending on whether you want to show the edge of the universe ... we are restricted to studying our observable universe. Discuss with your class the question ...

This is just a small part of the universe—less than 1% of the entire observable universe—but it is our galactic neighborhood. And it is good to know the geography of your neighborhood.

Whereabouts in that (admittedly oversimplified) scenario did we manage to lose sight of the observable universe? A lot of it comes down to the fact that traditionally, organizations need multiple ...