Oldest Rocks

The oldest terranes, with ages ranging from 3.8 Ga to 4.0 Ga, have been identified in Canada, while Australian zircon crystals dated at 4.4 Ga represent the oldest dated minerals on Earth. The exceptional resistance of zircon grains to repeated geological cycles has allowed dating 3.3–3.9 Ga crystals in several Archean cratons worldwide.

via 3.8 Ga zircons sampled by Neogene ignimbrite eruptions in Central Anatolia.

Ediacaran metazoan embryos?

Animal embryo-like fossils from the Ediacaran Doushantuo Formation, South China, have been interpreted as the earliest metazoan fossils, significantly predating the radiation of biomineralizing animals and macroscopic bilaterians during the Ediacaran–Cambrian transition.

This article discusses the fossilization process of these controversial structures

via The origin of intracellular structures in Ediacaran metazoan embryos.

Hubble Pinpoints Furthest Protocluster of Galaxies Ever Seen

Using the NASA/ESA Hubble Space Telescope, astronomers have uncovered a cluster of galaxies in the initial stages of development, making it the most distant such grouping ever observed in the early Universe.

In a sky survey made in near-infrared light Hubble has spotted five galaxies clustered together. They are so distant that their light has taken 13.1 billion years to reach us. These galaxies are among the brightest galaxies at that early stage of the Universe’s history. They are also very young: we are seeing them just 600 million years after the Universe’s birth in the Big Bang.

via Hubble Pinpoints Furthest Protocluster of Galaxies Ever Seen.

Human Evolution Out of Africa: The Role of Refugia and Climate Change

Although an African origin of the modern human species is generally accepted, the evolutionary processes involved in the speciation, geographical spread, and eventual extinction of archaic humans outside of Africa are much debated. An additional complexity has been the recent evidence of limited interbreeding between modern humans and the Neandertals and Denisovans. Modern human migrations and interactions began during the buildup to the Last Glacial Maximum, starting about 100,000 years ago. By examining the history of other organisms through glacial cycles, valuable models for evolutionary biogeography can be formulated. According to one such model, the adoption of a new refugium by a subgroup of a species may lead to important evolutionary changes.

via Human Evolution Out of Africa: The Role of Refugia and Climate Change.

Abundant star formation in the young universe was driven by high gas density

Recent results from the  Herschel Space Observatory show that gas-rich galaxies in the early universe were able to create stars at an intense rate.  In the recent universe, we only see such high rates of star formation when galaxies collide.  However, the Herschel data shows that while star-formation in some galaxies in the early universe were triggered by mergers, the majority of star forming galaxies were not undergoing interactions. The formation was driven by the amount of gas present.

via GOODS-Herschel reveals gas mass role in creating fireworks versus beacons of star formation.

Welcome to the Anthropocene

Watch a 3-minute journey through the last 250 years of our history, from the start of the Industrial Revolution to the Rio+20 Summit. The film charts the growth of humanity into a global force on an equivalent scale to major geological processes. The film is part of the world’s first educational webportal on the Anthropocene, commissioned by the Planet Under Pressure conference, and developed and sponsored by anthropocene.info

Globaïa

MISSION

Globaïa is a global education organization whose mission is to foster a consistent and informed participation of citizens in environmental issues by understanding the multiple dimensions of today’s world and its likely future.

OBJECTIVES

1. To promote a comprehensive, meaningful and unified vision of the contemporary world by providing young people, civil society, institutions, businesses and municipalities practical solutions and tools for action in order to promote change of lifestyle that can reduce our ecological and carbon footprints, making us more aware and resilient;

2. To enhance the effective participation of citizens in the major contemporary issues through a better understanding of big history and the multiple dimensions of our world;

3. To form and inform on major environmental issues of our time;

4. To establish partnerships and collaborations with other agencies, such Artcirq, to achieve the objectives of Globaïa.

via Globaïa.

Welcome to the Anthropocene

Welcome to the Anthropocene is a website which is designed to improve our collective understanding of the Earth system. The site aims to inspire, educate and engage people about humanity’s impact on Earth. Its unique combination of high-level scientific data and powerful imagery will help people visualize and better understand humanity’s geographic imprint in recent time.

via About Welcome to the Anthropocene.

A planetary system from the early Universe

A group of European astronomers has discovered an ancient planetary system that is likely to be a survivor from one of the earliest cosmic eras, 13 billion years ago. The system consists of the star HIP 11952 and two planets, which have orbital periods of 290 and 7 days, respectively. Whereas planets usually form within clouds that include heavier chemical elements, the star HIP 11952 contains very little other than hydrogen and helium. The system promises to shed light on planet formation in the early universe – under conditions quite different from those of later planetary systems, such as our own.

via A planetary system from the early Universe.

Fossil raindrop impressions imply greenhouse gases loaded early atmosphere

In ancient Earth history, the sun burned as much as 30 percent dimmer than it does now. Theoretically that should have encased the planet in ice, but there is geologic evidence for rivers and ocean sediments between 2 billion and 4 billion years ago.

Scientists have speculated that temperatures warm enough to maintain liquid water were the result of a much thicker atmosphere, high concentrations of greenhouse gases or a combination of the two.

Now University of Washington researchers, using evidence from fossilized raindrop impressions from 2.7 billion years ago to deduce atmospheric pressure at the time, have demonstrated that an abundance of greenhouse gases most likely caused the warm temperatures.

Their work, which has implications for the search for life on other planets, is published March 28 in Nature.

via Fossil raindrop impressions imply greenhouse gases loaded early atmosphere.