Organic Synthesis via Irradiation and Warming of Ice Grains in the Solar Nebula

New experimental results imply that organic compounds are natural by-products of protoplanetary disk evolution and should be important ingredients in the formation of all planetary systems, including our own.

Complex organic compounds, including many important to life on Earth, are commonly found in meteoritic and cometary samples, though their origins remain a mystery. Scientists examined whether such molecules could be produced within the solar nebula by tracking the dynamical evolution of ice grains in the nebula and recording the environments to which they were exposed. They found that icy grains originating in the outer disk, where temperatures were less than 30 kelvin, experienced ultraviolet irradiation exposures and thermal warming similar to that which has been shown to produce complex organics in laboratory experiments.

from Science Journal: Organic Synthesis via Irradiation and Warming of Ice Grains in the Solar Nebula.

The Story of Earth is retold in a new book due out tomorrow

Another History of the Earth book is due out tomorrow.

Dr. Robert M. Hazen, a research scientist at the Carnegie Institution of Washington’s Geophysical Laboratory and Clarence Robinson Professor of Earth Science at George Mason University, is the author of more than 300 articles and books on science, history, and music.

In his new book, The Story of Earth: The First 4.5 Billion Years, from Stardust to Living Planet, he tells the story of how Earth evolved from first atom to molecule, mineral to magma, granite crust to single cell to verdant living landscape.

The publishers call it a “radical new approach to Earth’s biography”. It explains how what Hazen calls “co-evolution” of the geosphere and biosphere—of rocks and living matter—has shaped our planet.

An interesting feature of the book is the description of pioneering men and women behind the sciences. Readers will meet black-market meteorite hawkers of the Sahara Desert, the gun-toting Feds who guarded the Apollo missions’ lunar dust, and the World War II Navy officer whose super-pressurized “bomb”—recycled from military hardware—first simulated the molten rock of Earth’s mantle. As a mentor to a new generation of scientists, Hazen introduces the intrepid young explorers whose dispatches from Earth’s harshest landscapes will revolutionize geology.

Earth Day 2012 – Mobilize the Earth with the Earth Day Network

On April 22, more than one billion people around the globe will participate in Earth Day 2012 and help Mobilize the Earth™. People of all nationalities and backgrounds will voice their appreciation for the planet and demand its protection. Together we will stand united for a sustainable future and call upon individuals, organizations, and governments to do their part.

Attend a local Earth Day event and join one of our Earth Day campaigns as we collect A Billion Acts of Green® and elevate the importance of environmental issues around the world. Together we will Mobilize the Earth™ on April 22 and demand change.

via Earth Day 2012 – Mobilize the Earth | Earth Day Network.

Barred Spiral Galaxy — Hubble Observes NGC 1073

Most spiral galaxies in the Universe have a bar structure in their centre, and Hubble’s image of NGC 1073 offers a particularly clear view of one of these. Galaxies’ star-filled bars are thought to emerge as gravitational density waves funnel gas toward the galactic centre, supplying the material to create new stars. The transport of gas can also feed the supermassive black holes that lurk in the centres of almost every galaxy.

Some astronomers have suggested that the formation of a central bar-like structure might signal a spiral galaxy’s passage from intense star-formation into adulthood, as the bars turn up more often in galaxies full of older, red stars than younger, blue stars. This storyline would also account for the observation that in the early Universe, only around a fifth of spiral galaxies contained bars, while more than two thirds do in the more modern cosmos.

via Classic Portrait of a Barred Spiral Galaxy — Hubble Observes NGC 1073.

Dramatic early star formation cut short by black holes

Early galaxies, flowering with dramatic starbursts in the early Universe, saw the birth of new stars abruptly cut short, leaving them as massive galaxies of aging stars in the present day. The likely culprit for the sudden end to the starbursts: the emergence of supermassive black holes.

via The Wild Early Lives of Today’s Most Massive Galaxies — Dramatic star formation cut short by black holes.