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The last time Venus drew nearer than 39.5 million km was in 1623, but that will not happen again for many millennia, and in fact after 5683 Venus will not even come closer than 40 million km for about 60,000 years. [8] The orientation of the orbits of the two planets is not favorable for minimizing the close approach distance. The longitudes of ...
Vesta (radius 262.7 ± 0.1 km), the second-largest asteroid, appears to have a differentiated interior and therefore likely was once a dwarf planet, but it is no longer very round today. [74] Pallas (radius 255.5 ± 2 km ), the third-largest asteroid, appears never to have completed differentiation and likewise has an irregular shape.
According to data from the Pioneer Venus Orbiter altimeters, nearly 51% of the surface is located within 500 meters (1,600 feet) of the median radius of 6,052 km (3,761 mi); only 2% of the surface is located at elevations greater than 2 kilometres (1.2 mi) from the median radius.
The Solar System is believed to have formed according to the nebular hypothesis, first proposed in 1755 by Immanuel Kant and independently formulated by Pierre-Simon Laplace. [2] This theory holds that 4.6 billion years ago the Solar System formed from the gravitational collapse of a giant molecular cloud. This initial cloud was likely several ...
Venus's equator rotates at 6.52 km/h (4.05 mph), whereas Earth's rotates at 1,674.4 km/h (1,040.4 mph). [note 2] [149] Venus's rotation period measured with Magellan spacecraft data over a 500-day period is smaller than the rotation period measured during the 16-year period between the Magellan spacecraft and Venus Express visits, with a ...
They make up a small area on Venus's global surface of around 7.2 x 10 8 km 2. [13] The lineament is the pattern of deformation, which make it a typical structural–material unit. [13] There is evidence showing the embayment of tessera by pdl's material in some tessera margins. Thus, it is possible that this unit is younger than the tessera ...
where a is the radius of the orbit, T is the period, G is the gravitational constant and M is the mass of the Sun. The third law explains the periods that occur during the year which relates the distance between the Earth and the Sun. [75] Along with unprecedent accuracy, the Keplerian model also allows put the Solar System into scale.
c. 200 BCE – Eratosthenes determines that the radius of the Earth is roughly 6,400 km (4,000 mi). [ 29 ] c. 150 BCE – According to Strabo (1.1.9), Seleucus of Seleucia is the first to state that the tides are due to the attraction of the Moon, and that the height of the tides depends on the Moon's position relative to the Sun. [ 30 ]