Dinosaurs existed on Earth, but in a completely different part of the galaxy: NASA explains how this is possible
Although most people living on planet Earth think of it as a slow-moving space ball that circles the Sun, the actual movement of all the planets in the Milky Way Galaxy is a bit more complicated. So the planet where dinosaurs once lived was located in a completely different part of our galaxy.
An animation of this fact was published by NASA researcher Jesse Christiansen (to watch the video, scroll to the end).
As the scientist explained, our Sun revolves around the centre of the galaxy, completing its rotation approximately every 250 million years. Of course, the entire system with its planets, including the Earth, rotates along with the Sun.
Christiansen's video shows that the last time our solar system was at its current position in the galaxy, the Triassic period was in full swing on Earth and dinosaurs had just been born, dominating our planet for millions of years. Since the dinosaur era lasted 165 million years, the Earth was in a completely different part of the Milky Way during this time.
Christiansen told Business Insider that the idea to create such an animation came about when she hosted a stargazing party at the California Institute of Technology in Pasadena. She shared with the audience that our solar system was on the other side of the galaxy when dinosaurs roamed, and everyone was very impressed.
"That was the first time I realised that these timelines - the archaeological, fossil and astronomical timelines - really do coincide," said Christiansen.
She noted that she then realised that she could draw "a map of dinosaur evolution through the rotation of the galaxy".
It took Christiansen about 4 hours to create the video. She also said that upon completion, she realised that she had made several mistakes in the text. In particular, it was stated that plesiosaurs are dinosaurs, but this is not the case. It also mistakenly states that the Earth completes its galactic orbit every 200 million years, when in fact it takes about 250 million years.
At the same time, as the scientist explains, the galactic motion in the video is somewhat simplified. The fact is that not only our solar system, but also other stars and systems move in their orbit. They all have not only different orbits, but also different rotation speeds. In addition, the inner regions of the galaxy rotate faster than the outer regions.
If we move to a larger scale, it turns out that the Milky Way is also moving through space, slowly approaching the neighbouring Andromeda galaxy. OBOZREVATEL told about what might happen when they collide here.
"The animation gives the impression that we are back in the same place, but in fact the whole galaxy has moved a very long way. It looks more like we are moving in a spiral in space. Because the whole galaxy is moving and we're rotating around the centre, it kind of creates this spiral," Christiansen explained.
Thus, as the solar system rotates around the galactic centre, the Earth does not return to a fixed point, as the surroundings are different from where we were last time.
The planet itself, however, remains the same. This is partly due to the trajectory of our Sun's galactic orbit.
"Our solar system does not travel to the centre of the galaxy and then return. We always stay at about the same distance," said Christiansen.
According to her, it is this feature that allows the Earth to remain habitable, because if its path went through the centre of the galaxy, everything would be much worse, as there are many stars and unstable systems in the centre of the galaxy, as well as a lot of radiation.
Earlier, OBOZREVATEL told about the fragments of the very first stars of the Universe that astronomers managed to see.