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The surface of Venus is comparatively flat. When 93% of the topography was mapped by Pioneer Venus Orbiter, scientists found that the total distance from the lowest point to the highest point on the entire surface was about 13 kilometres (8.1 mi), about the same as the vertical distance between the Earth's ocean floor and the higher summits of the Himalayas.
According to some researchers, the Earth's mantle and/or core might hold large quantities of hydrogen left there since the original formation of Earth from the nebular cloud. [25] [26] Since the original formation and inner structure of Earth and Venus are generally believed to be somewhat similar, the same might be true for Venus.
Planet Venus Observed with Modern Telescope on April 10, 2020. NASA's Magellan spacecraft mission discovered that Venus has a geologically young surface with a relatively uniform age of 500±200 Ma (million years). [3] The age of Venus was revealed by the observation of over 900 impact craters on the surface of the planet.
The LISA mission includes three spacecraft that will fly 2.5 million kilometers (about 1.6 million miles) apart in a triangle-shaped formation. Free-floating gold cubes within each spacecraft will ...
Overall, Venus has several times as many volcanoes as Earth, and it possesses some 167 giant volcanoes that are over 100 kilometres (62 mi) across. The only volcanic complex of this size on Earth is the Big Island of Hawaii. However, this is not because Venus is more volcanically active than Earth, but because its crust is older.
Because Venus is completely covered in clouds, human knowledge of surface conditions was largely speculative until the space probe era. Until the mid-20th century, the surface environment of Venus was believed to be similar to Earth, hence it was widely believed that Venus could harbor life.
Venus's atmosphere is composed of 96% carbon dioxide. Billions of years ago, when the Sun was 25 to 30% dimmer, Venus's surface temperature could have been much cooler, and its climate could have resembled current Earth's, complete with a hydrological cycle—before it experienced a runaway greenhouse effect. [44]
The formation of giant planets is an outstanding problem in the planetary sciences. [22] In the framework of the solar nebular model two theories for their formation exist. The first one is the disk instability model , where giant planets form in the massive protoplanetary disks as a result of its gravitational fragmentation (see above). [ 58 ]