[PLAIN]http://www.ibtimes.com/moons-tilted-orbit-explained-relic-impact-created-earth-moon-system-2439888 said:Written[/PLAIN] by lead author Matija Ćuk of the SETI Institute and others, the paper, titled “Tidal evolution of the Moon from a high-obliquity, high-angular-momentum Earth,” says Earth’s spin was much faster and at a much steeper angle when it initially formed about 4.5 billion years ago. Earth originally spun on its side with the moon orbiting around its equator, the paper said.
I'm not sure, but have you searched on the NASA pages? And it's more than two numbers, because the moon is gradually moving away from us, so it's rather a function of time.anorlunda said:That raised an interesting question in my mind. Wikipedia was not helpful providing answers.
Surely we must have estimates of Earth rotation rate and tilt both pre and post impact with Theia. What are those numbers?
According to a 2013 simulation, the Earth's rotation rate immediately after the Theia impact was 3.795 ± 0.405 hours. With Earth's axial tilt of 23.3° ± 1.2°. The moon's orbit about the Earth initially took 18.15 ± 0.24 hours, with an initial distance of 43,807.6 ± 416.4 km (just outside Earth's Roche Limit), with an eccentricity of 0.0775 ± 0.0005.anorlunda said:That raised an interesting question in my mind. Wikipedia was not helpful providing answers.
Surely we must have estimates of Earth rotation rate and tilt both pre and post impact with Theia. What are those numbers?
Earth's rotation is caused by the initial spin it acquired during its formation. Its tilt, also known as its axial tilt or obliquity, is caused by the gravitational pull of the sun and moon.
The rotation of Earth creates day and night, and also helps to regulate temperature and weather patterns. The tilt of Earth's axis causes the change of seasons and influences the amount of sunlight different parts of the planet receive.
Earth takes approximately 24 hours to make one full rotation on its axis. Its tilt is approximately 23.5 degrees.
If Earth's rotation speed changed, it would have a significant impact on the length of day and night, as well as weather patterns. If its tilt changed, it would alter the intensity and distribution of sunlight, which could potentially have an impact on global climate.
Earth's rotation and tilt are not constant, but they do change very slowly over time. For example, Earth's rotation is gradually slowing down, while its tilt oscillates between 22.1 and 24.5 degrees over a period of 41,000 years.