Is there a tenth planet in our solar system?
No. On August 23, 2006, the International Astronomical Union decided that the solar system contains only eight planets. Pluto, which […]
Is there a tenth planet in our solar system? Read More »
No. On August 23, 2006, the International Astronomical Union decided that the solar system contains only eight planets. Pluto, which […]
Is there a tenth planet in our solar system? Read More »
Alignments of the fast-moving inner planets can occur as regularly as every few months or so, while groupings of the
How often do all the planets line up? Read More »
Earth’s circumference was first accurately measured more than 2,000 years ago by the Greek astronomer Eratosthenes, who at the time
How was the size of Earth first measured? Read More »
The famous Northern and Southern Lights — Aurora Borealis and Aurora Australis for those Latin lovers among us — are
What causes the Northern and Southern Lights? Read More »
While no direct link between sunspots and Earthly events, such as volatile stock markets, has ever been found, extremes in
Can solar flares and sunspots affect Earth? Read More »
Most estimates place the number of stars in our galaxy at between 100 billion and 500 billion.
How many stars are in the Milky Way? Read More »
The Milky Way’s disk spans at least 100,000 light-years and probably contains several hundred billion stars, which makes our home
How big is our galaxy? Read More »
Quite a few. Most estimates place the number of galaxies at around 100 billion. Most of those galaxies are little
How many galaxies are there in the universe? Read More »
The largest visible-light telescope currently in operation is at Gran Canarias Observatory, and features a 10.4-meter (34-foot) primary mirror. The
What is the largest telescope? Read More »
The true inventor of the first telescope is somewhat difficult to nail down. However, the first person to apply for
Who invented the telescope? Read More »