Question: How big was the moon during the dinosaurs?
Scientists believe a collision between Earth and a protoplanet the size of Mars formed the moon 4.5 billion years ago. At this stage, the moon’s orbit was approximately 5,000 miles to 20,000 miles from Earth.
Birth of the Moon
Once the moon was created, the temperature was immensely hot. Large deposits of magma rock formed the outer surface. If viewed from Earth at this time, the moon would’ve appeared reddish in color and 15 times larger in width than the present moon. After the first few tens of millions of years, areas of the moon’s surface cooled down in temperature, and solidification occurred. Between 4.1 billion and 3.8 billion years ago, huge impacts occurred on the moon. As a result, immense lava flow caused flooding in large areas of the moon. Eventually, by 3.8 billion years ago, much of the lava had cooled down to form dark plains.
The Mesozoic Era
The dinosaurs lived on Earth about 250 million years ago during the Mesozoic era. The most recent dinosaurs existed about 85 million years ago during the Cretaceous Period. The Moon was well-established by that stage and would have been closer to the Earth, but the moon’s physical appearance wouldn’t have appeared markedly larger in the sky.
Here is why: At present, the moon is moving at approximately 1,5 inches away from us each year. Thus, 1,5 inches for 85 million years equates to 127,500,000 inches. Although that number seems massive, 127,500,000 inches is 10,625,000 feet and 2012 miles. To put this into perspective, the total distance across the moon is about 2,000 miles. The moon is currently 240,000 miles away from Earth. In the past, it was about 2,000 miles closer to us.
To summarize, when the last dinosaurs roamed the planet, the moon was about 0.8% larger in size. When it was viewed from Earth during that time in history, the size would’ve appeared roughly the same as the present day. There were also fewer craters on its surface. Lava might’ve been seen on the surface as volcanic activity occurred longer than previously thought.
Scientists originally thought that volcanic eruptions subsided a billion years ago. However, NASA’s Lunar Reconnaissance Orbiter has collected data to suggest volcano activity might’ve been present less than 100 million years ago.