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Weather forecast for early Earth involved iron rain

Early weather reports on Earth could have forecast iron rain. Our planet may have experienced such storms in its youth, which would help to explain the preponderance of precious metals in Earth's mantle and crust today.
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Title: Photometric Variability of the Disk Integrated Infrared Emission of the Earth
Authors: I. Gómez-Leal, E. Pallé, F. Selsis

We present an analysis of the global-integrated mid-infrared emission flux of the Earth based on data derived from satellite measurements. We have studied the photometric annual, seasonal, and rotational variability of the thermal emission of the Earth to determine which properties can be inferred from the point-like signal. We find that the analysis of the time series allows us to determine the 24 hr rotational period of the planet for most observing geometries, due to large warm and cold areas, identified with geographic features, which appear consecutively in the observer's planetary view. However, the effects of global-scale meteorology can effectively mask the rotation for several days at a time. We also find that orbital time series exhibit a seasonal modulation, whose amplitude depends strongly on the latitude of the observer but weakly on its ecliptic longitude. As no systematic difference of brightness temperature is found between the dayside and nightside, the phase variations of the Earth in the infrared range are negligible. Finally, we also conclude that the phase variation of a spatially unresolved Earth-Moon system is dominated by the lunar signal.

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 Researchers have forecast the eventual fate of our own planet.

A group of astrophysicists studying the dust of shattered "corpse planets" in the atmospheres of dying white dwarf stars have highlighted a doomsday scenario, which states that one day in the distant future, the sun will explode and destroy our nearby planets, roast the Earth's surface and probably kill us all.
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Our voyage through the Milky Way

For billions of years, Earth has been on a perilous journey through space. As our planet whirls around the sun, the whole solar system undertakes a far grander voyage, circling our island universe every 200 million years. Weaving our way through the disc of the Milky Way, we have drifted through brilliant spiral arms, braved the Stygian darkness of dense nebulae, and witnessed the spectacular death of giant stars.
Many of these marvels may well have been deadly, raining lethal radiation onto Earth's surface or hurling huge missiles into our path. Some may have wiped out swathes of life, smashed up continents or turned the planet to ice. Others may have been more benign, perhaps even sowing the seeds of life.

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Early Earth may have been prone to deep freezes

Two University of Colorado Boulder researchers who have adapted a three-dimensional, general circulation model of Earth's climate to a time some 2.8 billion years ago when the sun was significantly fainter than present think the planet may have been more prone to catastrophic glaciation than previously believed.
The new 3-D model of the Archean Eon on Earth that lasted from about 3.8 billion years to 2.5 billion years ago, incorporates interactions between the atmosphere, ocean, land, ice and hydrological cycles, said CU-Boulder doctoral student Eric Wolf of the atmospheric and oceanic sciences department. Wolf has been using the new climate model -- which is based on the Community Earth System Model maintained by the National Centre for Atmospheric Research in Boulder -- in part to solve the "faint young sun paradox" that occurred several billion years ago when the sun's output was only 70 to 80 percent of that today but when geologic evidence shows the climate was as warm or warmer than now.
In the past, scientists have used several types of one-dimensional climate models -- none of which included clouds or dynamic sea ice -- in an attempt to understand the conditions on early Earth that kept it warm and hospitable for primitive life forms. But the 1-D model most commonly used by scientists fixes Earth's sea ice extent at one specific level through time despite periodic temperature fluctuations on the planet, said Wolf.

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NASA Research Confirms it's a Small World, After All

Since Charles Darwin's time, scientists have speculated that the solid Earth might be expanding or contracting. That was the prevailing belief, until scientists developed the theory of plate tectonics, which explained the large-scale motions of Earth's lithosphere, or outermost shell. Even with the acceptance of plate tectonics half a century ago, some Earth and space scientists have continued to speculate on Earth's possible expansion or contraction on various scientific grounds.
Now a new NASA study, published recently in Geophysical Research Letters, has essentially laid those speculations to rest. Using a cadre of space measurement tools and a new data calculation technique, the team detected no statistically significant expansion of the solid Earth.

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The Earth's geoid
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The Earth's geoid



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Title: La2010: A new orbital solution for the long term motion of the Earth
Authors: J. Laskar, A. Fienga, M. Gastineau, H. Manche

We present here a new solution for the astronomical computation of the orbital motion of the Earth spanning from 0 to -250 Myr. The main improvement with respect to the previous numerical solution La2004 (Laskar et al. 2004) is an improved adjustment of the parameters and initial conditions through a fit over 1 Myr to a special version of the high accurate numerical ephemeris INPOP08 (Fienga et al. 2009). The precession equations have also been entirely revised and are no longer averaged over the orbital motion of the Earth and Moon. This new orbital solution is now valid over more than 50 Myr in the past or in the future with proper phases of the eccentricity variations. Due to chaotic behaviour, the precision of the solution decreases rapidly beyond this time span, and we discuss the behaviour of various solutions beyond 50 Myr. For paleoclimate calibrations, we provide several different solutions that are all compatible with the most precise planetary ephemeris. We have thus reached the time where geological data are now required to discriminate among planetary orbital solutions beyond 50 Myr.

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New theory on the origin of water on Earth

The origin of water on our planet is not only of interest for our understanding of the evolution of our own planet and life thereon, but even more so for the increasing exploration of other planets within our solar system and the discovery of potential planetary systems in other galaxies.
Having spent half a lifetime teaching his students the accepted versions of the origin of our planetary water, which increasingly did not fit the available evidence, Dr Mike Drake at the University of Arizona suggested an alternative hypothesis: that water was already present at the surfaces of interstellar dust grains when they accreted to form our planet. Although this hypothesis fitted with all available evidence, it would only be feasible if the adhesion of water to the dust grains was sufficiently strong to survive the harsh conditions in the interstellar dust clouds where planets form.

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Earth may have had water from day one

In the beginning, there was water. Earth's life-sustaining liquid came from the dust from which the planet was born, a new look at these particles suggests, and not simply from collisions with objects that later crashed into the planet from space.
The origin of the oceans has long been a mystery. Earth's birthplace in the dusty nebula around the young sun should have been hot enough to keep any water vaporised.

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