Skip to main content

The Early Earth Wasn’t Completely Terrible

Earth formed 4.54 billion years ago. The first period of the history of the Earth was known as the Hadean Period which lasted from 4.54 billion to 4 billion years ago. During that time, Earth was thought to be a magma filled, volcanic hellscape. It all sounds rather inhospitable at this stage but even then, liquid oceans of water are thought to have existed under an atmosphere of carbon dioxide and nitrogen. Recent research has shown that this environment may well have been rather more habitable than once thought. 


The name ‘Hadean’ comes from Hades, the Greek god of the underworld. It nicely reflects the hot, hostile climate of the early Earth. During this period, Earth was largely a molten, chaotic world with volcanic eruptions a common sight on the landscape. Overhead, there would be regular visitors from space with meteorites and comets impacting the surface as the crust is still forming. Despite these conditions, it seems that water also began to accumulate as the planet cooled, possibly having been delivered by comets or released from outgassing from giant volcanoes. By the end of the era, the crust had solidified enough to form two early continents separated by forming oceans. 

Artist concept of Earth during the Late Heavy Bombardment period. Credit: NASA’s Goddard Space Flight Center Conceptual Image Lab.

In a paper published by a team of researchers from the University of California they confirm this conclusion that, far from being in hospitable, early Earth was actually far less tumultuous. The team, led by Christopher K Jones explore the evolution of the Earth from formation to the evolution of life. They review a number of different pathways for the origins of life during the Hadean in the context of the large-scale planetary environment at the time, including Earth’s position in the Solar System.

This view of Earth from space is a fusion of science and art, drawing on data from multiple satellite missions and the talents of NASA scientists and graphic artists. This image originally appeared in the NASA Earth Observatory story Twin Blue Marbles. Image Credits: NASA images by Reto Stöckli, based on data from NASA and NOAA.

In order to complete their work, the team look at the a number of critical aspects across different disciplines that included microbiology, atmospheric chemistry, geochemistry and planetary science. The relationships between life’s beginnings and the processes and state of the environment at the time is also assessed in their paper including the formation of the crust and evolution of the atmosphere. 

The paper also explores a number of different atmospheric processes from wet-dry and freeze-thaw cycles to hydrothermal vent systems. This is not just assessed on Earth but in the Solar System at large to see if there is any correlation or overlaps. The impact of comets too are considered and how they would impact on the atmospheric chemistry. 

According to a new study, a comet impact triggered massive wildfires and a temporary cooling 12,800 years ago. Credit: NASA/Don Davis

The team conclude that Earth, during the Hadean period, most likely had liquid water. The debate still rages on however about the existence of continents and their composition. This uncertainty has an impact on just how organic life could have got a foothold on Earth. However it did, life would have taken a hold by the end of the Hadean era and started to leave evidence in the geological records of the Archean period that followed. 

Unfortunately the paper is far from conclusive, leaving a number of questions unanswered but it does make a fabulous start to fill in the gaps at just how life began on this planet we call home.

Source : Setting the stage: Building and maintaining a habitable world and the early conditions that could favour life’s beginnings on Earth and beyond

The post The Early Earth Wasn’t Completely Terrible appeared first on Universe Today.



from Universe Today https://ift.tt/FRYJSkr
via IFTTT
Labels:

Comments

Post a Comment

Popular posts from this blog

A Magnetohydrodynamic Drive Could Lead to Fuel Stations on Mars

Within the next fifteen years, NASA, China, and SpaceX plan to send the first crewed missions to Mars. In all three cases, these missions are meant to culminate in the creation of surface habitats that will allow for many returns and – quite possibly – permanent human settlements. This presents numerous challenges, one of the greatest of which is the need for plenty of breathable air and propellant. Both can be manufactured through electrolysis, where electromagnetic fields are applied to water (H 2 O) to create oxygen gas (O 2 ) and liquid hydrogen (LH 2 ). While Mars has ample deposits of water ice on its surface that make this feasible, existing technological solutions fall short of the reliability and efficiency levels required for space exploration. Fortunately, a team of researchers from Georgia Tech has proposed a “ Magnetohydrodynamic Drive for Hydrogen and Oxygen Production in Mars Transfer ” that combines multiple functionalities into a system with no moving parts. This syst...
Post a Comment
Read more

SETI Researchers Double-Checked 1 Million Objects for Signs of Alien Signals

We can’t help ourselves but wonder about life elsewhere in the Universe. Any hint of a biosignature or even a faint, technosignature-like event wrests our attention away from our tumultuous daily affairs. In 1984, our wistful quest took concrete form as SETI, the Search for Extraterrestrial Intelligence . Unfortunately, or maybe fortunately, SETI has turned up nothing. Recently, scientists used a powerful new data system to re-examine data from one million cosmic objects and still came up empty-handed. Did they learn anything from this attempt? This effort used COSMIC , which stands for  Commensal Open-Source Multimode Interferometer Cluster . It’s a signal-processing and algorithm system attached to the Karl G. Jansky  Very Large Array  (VLA) radio astronomy observatory. According to SETI, it’s designed to “search for signals throughout the Galaxy consistent with our understanding of artificial radio emissions. “ Modern astronomy generates vast volumes of data and al...
Post a Comment
Read more

A New Technique Has Dramatically Improved ALMA’s Resolution

To those familiar with optical telescopes, the idea of doing something to achieve higher resolution with their telescope may seem alien, if not, then practically impossible. A telescopes resolution is determined by among other things, its aperture – diameter of the thing that collects light (or electromagnetic radiation) and of course you can’t easily change that. Enter the team at ALMA, the Atacama Large Millimeter Array who have become the first to use the Band 10 receiver and extreme separation of the receivers to boosting its resolution so they can see detail equivalent of detecting a 10 meter long bus on the Moon! The Atacama Large Millimeter/submillimeter Array (otherwise known as ALMA) is based upon interferometer technology which, in its simplest terms, takes a number of telescopes, hooks them together and gives them the same amount of resolution as if the instrument was the same diameter as the distance between the component parts! If that blew your mind then let me explain;...
Post a Comment
Read more