Earth and Venus are similar in many ways. They are similar in size, mass, and density, and are relatively similar distances from the Sun. However, some key differences, such as the possibility of life, the composition of the atmosphere, and plate tectonics, remain unclear.
The terrestrial planets in the solar system are believed to have formed as a result of the violent collisions of dozens of protoplanets ranging in size from the Moon to Mars. It happened about 200 million years after the protoplanetary gas disk dissipated.
Protoplanets are astronomical bodies that are still in an early stage of the evolution of a planet that has not yet completed its growth in mass and size. It is not a strictly defined term. The diameters of the protoplanets range from 100 to 10,000 km. Protoplanets are formed in the initial period of the formation of a planetary system and turn into planets, or stop their development and become large asteroids. They are large enough to attract, by their gravity, grains of matter with a diameter of centimeters and the minor planets, which are objects of intermediate dimensions between the grains and the protoplanets.
Gas and ice giants form very quickly during the protoplanetary disk phase, and then disperse EmigratedThat is, they moved to or from the Sun in interaction with the minor planets of the outer disk. Less than 100 million years after this dispersal, Jupiter is thought to have approached a planet-sized orb. Consequently I jumped to the center of the solar system By 0.2-0.5 AU when descending into its current, moderately eccentric orbit.
Computer simulations that recreate the interactions between protoplanets and minor planets show that this castle cannot remain unaffected by the formation of terrestrial planets. It was one of the consequences gravity echoWhich removed the planets from about 1.5 astronomical units. This caused a sharp decrease in the rate of accumulation of small planets on larger bodies and prevented the growth of Mars.
Computer simulations predicted that Venus’ strong collisions with smaller bodies in the solar system could explain why Venus is so different from its rocky sister planet Earth.
The animation shows a computer simulation of a massive planetary collision. 100 million particles were used in the calculations. The colors reflect the internal energy of these particles, which is an indication of their temperature. Source: Dr. Jacob Kegres, Durham University
In the early existence of the Solar System, collisions between the objects that built them were very active because the dimensions and velocities of the colliding objects were very high. The collision of a planet with an object more than a few hundred kilometers in diameter can have an effect on the depth of the planet’s interior, surface and atmosphere, which is basically all about the planet.
The collisions experienced by Venus during the late accretion phase, about 4.5 to 4.0 billion years ago, may have occurred much faster than those on Earth. Speeds of more than a quarter of collisions with Venus can reach at least 30 kilometers per second, or about 100,000 kilometers per hour! Such strong influences on Venus could completely melt the cover of this planet.
Pictured: A computer simulation showing a massive planet hitting a Venus-like planet. The middle and right panels show Venus 1 hour and 11 hours after impact. The colors indicate the temperature as shown in the legend. Source: Southwest Research Institute / Simon Marchi and Raluca Ruffo.
Even if there was only one such collision, it would have the ability to fundamentally disrupt and reset the evolution of the entire planet. Venus can transform from a solid, rocky body into a mass of molten matter in moments, which could change the mineral and physical composition of the planet’s interior and surface. Any pre-existing atmosphere will be largely blown away and replaced by volatile gases escaping from the magma.
A single high-speed collision could eventually determine the likely formation of plate tectonics, an important aspect of the potential for formation and duration of life on the planet. This may be why Venus and Earth found themselves on divergent evolutionary paths, leading Venus into its current form: a dry, dry planet covered in an atmosphere 90 times greater than Earth’s pressure and a temperature twice the height of a furnace (about 500thec).
These collisions were responsible for the formation of the solar system. Without these processes, we would be living in a completely different environment, and we probably wouldn’t be here. To better understand our history, it is necessary to explain the extent to which these early violent events shaped our planet.
By Joanna Mulinda-Żakowicz
Pictured: the effect (inset) and its consequences (main image) in a 3D simulation of a massive planetary collision. 100 million particles were used in the calculations. The colors reflect the internal energy of these particles, which is an indication of their temperature. Source: Dr. Jacob Kegres, Durham University