While it's commonly accepted that the Earth is round, recent findings challenge this belief.
Early in its existence, Earth may have been flatter, resembling a Smartie. Prior assumptions about protoplanets forming as spheres have been reconsidered.
New Insights Challenge Spherical Assumptions in Early Planet Formation
Researchers from the University of Central Lancashire have examined the three-dimensional shapes of nascent planets in simulations for the first time, revealing surprising findings. They discovered that newborn planets exhibited oblate spheroids resembling Smarties, challenging the longstanding assumption of their spherical formation.
Dr. Dimitris Stamatellos, co-author of the study, expressed astonishment at the discovery, emphasizing that the team had always assumed the planets would be spherical in their simulations of planet formation.
The commonly observed planets, including Earth, are predominantly spherical or very close to being spherical. However, the researchers behind this study now propose that protoplanets undergo significant flattening, estimated at around 90%.
This revelation adds a new dimension to our understanding of the protoplanet phase, believed to last between 1 to 5 million years in a planet's early existence. Given Earth's age of approximately 4.5 billion years, it suggests that it might have had a Smartie-shaped configuration for only a fraction of its initial history.
The study, titled "The 3D structure of disc-instability protoplanets" published in Astronomy & Astrophysics Letters, explores two leading theories for protoplanet formation: the core accretion theory and the disc-instability theory. The former posits gradual growth from dust particles, while the latter suggests rapid formation from a disintegrating gas disc around a young star.
Simulations based on the disc-instability theory surprisingly yielded flattened protoplanets, challenging previous assumptions and requiring extensive computational resources.
The researchers propose that the flattening of protoplanets occurs within a spinning disk, akin to a chef stretching and flattening pizza dough. This force causes the protoplanets to adopt a flattened shape. The team believes that protoplanets transition to a spherical shape later in their evolution when gas and matter accumulate more rapidly at their poles than at the equator.
These findings may offer valuable insights into the ongoing debate surrounding planet formation, particularly as telescopic observations become more advanced, allowing for potential verification of protoplanet flattening.
How Did Scientists Confirm Earth's Round Shape?
The Earth, like other planets, is a sphere that rotates continuously on its axis, completing one rotation approximately every 24 hours. This rotation results in different parts of the Earth facing the sun at various times, causing day and night in different regions. Scientists have multiple reasons to assert the Earth's roundness over flatness, and these reasons are accessible for personal verification.
For instance, if the Earth were flat, we would be able to see very far, unobstructed by buildings. However, our visual range is limited due to the Earth's curvature. Observing a sunset experiment also demonstrates the Earth's roundness, as the sun reappears briefly when moving to a higher spot after disappearing beyond the horizon.
Additionally, the changing lengths of shadows in different locations provide evidence of the Earth's spherical shape, as shadows would be uniform on a flat surface. During a lunar eclipse, the Earth casts a round shadow on the moon, reinforcing the understanding that the Earth is a sphere rather than a flat or pancake-shaped object.
RELATED ARTICLE: Why Celestial Bodies Tend to Be Spherical: Unraveling the Influence of Gravity in Space
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