Search results
Results From The WOW.Com Content Network
In contrast, the Lunar distance (LD or ), or Earth–Moon characteristic distance, is a unit of measure in astronomy. More technically, it is the semi-major axis of the geocentric lunar orbit . The average lunar distance is approximately 385,000 km (239,000 mi), or 1.3 light-seconds . [ 1 ]
The distance between the Moon and Earth varies from around 356,400 km (221,500 mi) to 406,700 km (252,700 mi) (apogee), making the Moon's distance and apparent size fluctuate up to 14%. [203] [204] On average the Moon's angular diameter is about 0.52°, roughly the same apparent size as the Sun (see § Eclipses).
Proposition 7 states that the distance of the Sun from the Earth is greater than 18 times, but less than 20 times, the distance of the Moon from the Earth (Heath 1913:377). In other words, the Sun is 18 to 20 times farther away and wider than the Moon.
Earth and the Moon as seen from cislunar space on the 2022 Artemis 1 mission. xGeo space is a concept used by the US to refer to space of high Earth orbits, ranging from beyond geosynchronous orbit (GEO) at approximately 35,786 km (22,236 mi), [103] out to the L2 Earth-Moon Lagrange point at 448,900 km (278,934 mi).
The Sun's gravitational effect on the Moon is more than twice that of Earth's on the Moon; consequently, the Moon's trajectory is always convex [26] [27] (as seen when looking Sunward at the entire Sun–Earth–Moon system from a great distance outside Earth–Moon solar orbit), and is nowhere concave (from the same perspective) or looped.
The tidal forces are about 1,000 times stronger than the Moon's effect on Earth. The only other moon in the Solar System exhibiting water vapor plumes is Enceladus. [22] The estimated eruption rate at Europa is about 7000 kg/s [120] compared to about 200 kg/s for the plumes of Enceladus.
This is because the distance between Earth and the Sun is not fixed (it varies between 0.983 289 8912 and 1.016 710 3335 au) and, when Earth is closer to the Sun , the Sun's gravitational field is stronger and Earth is moving faster along its orbital path. As the metre is defined in terms of the second and the speed of light is constant for all ...
Length of a meridian on Earth (distance between Earth's poles along the surface) [37] 40.075 Mm Length of Earth's equator: 10 8: 100 Mm: 142.984 Mm Diameter of Jupiter: 299.792 Mm Distance traveled by light in vacuum in one second (a light-second, exactly 299,792,458 m by definition of the speed of light) 384.4 Mm Moon's orbital distance from ...