Grades 6-8 (Ages 11-13) Archives — Page 9 of 9

What causes tides?

For the most part, the rise and fall of the tides is caused by the gravitational influence of the Moon. […]

The farthest known object orbiting our Sun is a ball of ice and rock unofficially called FarFarOut, which lies about

No. On August 23, 2006, the International Astronomical Union decided that the solar system contains only eight planets. Pluto, which

Alignments of the fast-moving inner planets can occur as regularly as every few months or so, while groupings of the

Earth’s circumference was first accurately measured more than 2,000 years ago by the Greek astronomer Eratosthenes, who at the time

The famous Northern and Southern Lights — Aurora Borealis and Aurora Australis for those Latin lovers among us — are

While no direct link between sunspots and Earthly events, such as volatile stock markets, has ever been found, extremes in

Most estimates place the number of stars in our galaxy at between 100 billion and 500 billion.

The Milky Way’s disk spans at least 100,000 light-years and probably contains several hundred billion stars, which makes our home

Quite a few. Most estimates place the number of galaxies at around 100 billion. Most of those galaxies are little