In the 1930s, when American mathematician and astronomer Percival Lowell decided to search for a planet beyond Neptune, he called the hypothetical planet Planet X. This search led to the discovery of Pluto, but for many years some astronomers believed that another world larger than Pluto must exist undiscovered beyond Neptune. They thought this because Neptune’s orbit seemed to be influenced by the gravity of an unseen planet. More recent studies indicate that a large Planet X most likely does not exist, but the term Planet X is still used in pop culture for an undiscovered planet in our solar system.
- Which planets are called the gas giants?
- Why isn’t Pluto a planet anymore?
- Which planets are the rocky planets?
- How many planets are there?
- What is a planet?
- What is an orbit?
- How old is the solar system?
- What is the solar system?
- Why is the Andromeda galaxy so special?
- Which galaxy is closest to ours?
- What is outer space?
- Is Earth at the center of the universe?
- Is it possible for the universe to collapse instead?
- Is the universe expanding?
- What is a light year?
- How does the universe stay together?
- How big is the universe?
- How did the universe begin?
- What is Global Account Management
- What is GlaxoSmithKline
