"General relativity is physicist Albert Einstein's understanding of how gravity affects the fabric of space-time."
https://www.space.com/17661-theory-general-relativity.html
"The possibility of time travel is based on Einstein’s general theory of relativity, developed in 1915. This is due to the prediction of the general theory of relativity that time is affected by gravity. According to this theory, the stronger the gravity, the more time slows down."
https://www.eetimes.eu/relativity-and-time-travel/
"A year is defined as the time it takes a planet to complete one revolution of the Sun, for Earth this is just over 365 days. This is also known as the orbital period. Unsurprisingly the the length of each planet’s year correlates with its distance from the Sun"
"Mercury: 87.97 days (0.2 years)
Venus : 224.70 days (0.6 years)
Earth: 365.26 days(1 year)
Mars: 686.98 days(1.9 years)
Jupiter: 4,332.82 days (11.9 years)
Saturn: 10,755.70 days (29.5 years)
Uranus: 30,687.15 days (84 years)
Neptune: 60,190.03 days (164.8 years)"
https://space-facts.com/orbital-periods-planets/
"There are many planetary systems like ours in the universe, with planets orbiting a host star. Our planetary system is called “the solar system” because we use the word “solar” to describe things related to our star, after the Latin word for Sun, "solis.""
https://solarsystem.nasa.gov/solar-system/our-solar-system/overview/
"All in all, gravity runs the gamut here in the solar system, ranging from 0.38 g on Mercury and Mars to a powerful 2.528 g atop Jupiter's clouds. And on the Moon, were astronauts have ventured, it is a very mild 0.1654 g, which allowed from some fun experiments in near-weightlessness!
Understanding the effect of zero-gravity on the human body has been essential to space travel, especially where long-duration missions in orbit and to the International Space Station have been concerned"
https://phys.org/news/2016-01-strong-gravity-planets.html