On the vertical growth of continents in deep depressions of the Earth’s peridotite mantle

Research subject. The geological structure and evolution of the Earth’s continents.Methods. This article is based on a long-term study and review of geological, geophysical and bathymetric published data, as well as on an analysis of the major geological discoveries of the 20th century.Results and conclusions. It is established that all the continents on the Earth, except for Antarctica, constitute a single Northen megamaterik, which was being formed during a prolonged period of time (4.4 billion years) in a deep three-beam cavity on the surface of the peridotite mantle. The ancient Hadean– Archean basement of the megacontinent was being formed during the period of 3 billion years, which comprises about 70% of the Earth’s geological history. In the Late Proterozoic and Phanerozoic, periodically formed local depressions were flooded with sedimentary material leading to the formation of sedimentary basins and folded rock structures. As a result, the thickness of the megacontinent’s crust steadily increased reaching a large size of 15–40 or 60–70 km. During this period, the primary oceanic (peridotite) crust with a thickness of 3–5 km remained unchanged until the Mesozoic–Cenozoic, when it was covered with a layer of younger basalts and loose rock sediments with a thickness of 1–2 km.

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Design and ballistic analysis of the mission for long-term study of the asteroid Apophis by a nanosatellite with an electric rocket propulsion system

Spacecrafts & Technologies ◽

10.26732/j.st.2020.3.04 ◽

2020 ◽

Vol 4 (3) ◽

pp. 161-170

Author(s):

O. L. Starinova ◽

E. A. Sergaeva ◽

A. Yu. Shornikov

Keyword(s):

Propulsion System ◽

Gravitational Attraction ◽

Term Study ◽

Small Bodies ◽

Rocket Propulsion ◽

Gravitational Fields ◽

Optimal Speed ◽

Long Term Study ◽

The Earth

The paper considers non-spherical objects with low gravitational attraction, such as asteroids, satellites of the planet and comets. We considered possibility of a mission to small bodies of the solar system of irregular shape on the example of the asteroid Apophis. The authors of the article suggest using a nanoclass spacecraft with an electric rocket propulsion system for a long mission to study Apophis. The purpose of this work is to determine the necessary costs of the working body for all stages of the mission, which includes reaching the asteroid, forming and maintaining a given orbit relative to it. The gravity of the Earth, Sun, and asteroid is taken into account when modeling the controlled movement of the spacecraft. When a spacecraft is moving relative to an asteroid, its gravitational field is described as a superposition of the gravitational fields of two rotating massive points. In this paper, it is proposed to divide the mission into two sections for preliminary ballistic design. The first optimal speed heliocentric flight Earth-asteroid Apophis with the alignment of the speed of the spacecraft and the asteroid. The second is the movement in the vicinity of the asteroid, which includes the optimal speed maneuver for forming the working orbit and maintaining the working orbit for a given time.

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