The Snowball Earth hypothesis proposes that, during one or more of Earth's icehouse climates, the planet's surface became entirely or nearly entirely frozen.It is believed that this occurred sometime before 650 M.Y.A. (million years ago) during the Cryogenian period. Proponents of the hypothesis argue that it best explains sedimentary deposits that are generally believed to be of …

Schneeball Erde (englisch Snowball Earth) oder Schneeball-Erde ist eine geowissenschaftliche Hypothese über mehrere globale Vereisungen im späten Präkambrium (Neoproterozoikum), deren letzte Phase vor etwa 580 Millionen Jahren endete.Während dieser Eiszeitalter seien Gletscher von den Polen bis in Äquatornähe vorgestoßen, das Meer sei …

Earth is the third planet from the Sun in the Solar System.It is the only planet known to have life on it. The Earth formed about 4.5 billion years ago. It is one of four rocky planets on the inner side of the Solar System.The other three are Mercury, Venus, and Mars.. The large mass of the Sun keeps the Earth in orbit through the force of gravity. Earth also turns around in space, so that ...

A "greenhouse Earth" is a period during which no continental glaciers exist anywhere on the planet. Additionally, the levels of carbon dioxide and other greenhouse gases (such as water vapor and methane) are high, and sea surface temperatures (SSTs) range from 28 °C (82.4 °F) in the tropics to 0 °C (32 °F) in the polar regions. Earth has been in a greenhouse state for about …

The nucleus is the solid, central part of a comet, once termed a dirty snowball or an icy dirtball.A cometary nucleus is composed of rock, dust, and frozen gases.When heated by the Sun, the gases sublime and produce an atmosphere surrounding the nucleus known as the coma.The force exerted on the coma by the Sun's radiation pressure and solar wind cause an enormous …

The first eon in Earth's history, the Hadean, begins with the Earth's formation and is followed by the Archean eon at 3.8 Ga.: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, soon after the formation of the Earth's crust and the Earth itself. The giant impact hypothesis for the Moon's formation states that shortly ...

The Snowball Earth hypothesis maintains that the severe freezing in the late Proterozoic was ended by an increase in CO 2 levels in the atmosphere, mainly from volcanoes, and some supporters of Snowball Earth argue that it was caused in the first place by a reduction in atmospheric CO 2. The hypothesis also warns of future Snowball Earths.

A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor (H 2 O), carbon dioxide (CO 2), methane (CH 4), nitrous oxide (N 2 O), and ozone (O 3).Without greenhouse gases, the average temperature of …

Lanchester's laws are mathematical formulae for calculating the relative strengths of military forces.The Lanchester equations are differential equations describing the time dependence of two armies' strengths A and B as a function of time, with the function depending only on A and B.. In 1915 and 1916, during World War I, M. Osipov and Frederick Lanchester independently …

The Sturtian glaciation was a glaciation, or perhaps multiple glaciations, during the Cryogenian Period when the Earth experienced repeated large-scale glaciations. The duration of the Sturtian glaciation has been variously defined, with dates ranging from 717 to 643 Ma. Stern et al. place the period at 715 to 680 Ma.. According to Eyles and Young, "Glaciogenic rocks figure …