Exploding star remnants found in fossilized bacteria
Thousands of metres below the sea, trapped in the fossilized remains of ancient bacteria, exists the iron remnants of a supernova explosion that happened millions of years ago. An imprint, here on Earth, of a dying star.
Iron-60, an isotope of iron created only in supernovae, has been found in fossilised seabed bacteria. The preliminary findings, announced by Shawn Bishop of the Technical University of Munich at a 14 April meeting of the American Physical Society in Colorado, may be the first time that a specific star’s debris has been found in our fossil record.
Iron-60’s half-life is relatively short when compared to the age of our solar system, so traces of the isotope on Earth suggests a direct interaction with a supernova in the planet’s history. The researchers searched for the isotope in fossils from seabed samples between 1.7 million to 3.3 million years old. They likely found traces of the isotope in fossils around 2.2 million years old.
The bacteria containing the Iron-60 are magnetotactic; they are strange organisms live in the seabed and align themselves with the Earth’s magnetic field. They extract iron from the water and sediment around them and create iron oxide crystals that are then preserved in the fossil record.
“For me, philosophically, the charm is that this is sitting in the fossil record of our planet,” said Bishop in a Nature.com report. The isotope had previously been discovered in seabed samples, but not in the fossil record.
“We are all, as Carl Sagan put it, stardust,” Bishop told Wired.co.uk. “[We have now] likely discovered, within crystal nano-fossils left behind by primitive bacteria, […] still-live radioactive atoms that can only have been synthesized within the same kind of nuclear furnace — an exploding star — that forged the elements from which all live on Earth is made. The cycle comes full-circle.”
It has been estimated that the supernova happened around 2.2 million years ago, and that the stream of cosmic rays would have had an effect on the Earth’s atmosphere by increasing cloud cover. The supernova responsible for depositing the iron-60 has not yet been found, but possible suspects have been identified in the nearby Scorpius-Centarus association.
This isn’t the first time that distant astronomical events have made an impact on Earth. In 2012, researchers found a surplus of radioactive atoms in Japanese trees, hinting at a violent cosmic event around 1,200 years ago.
If you’re in the area don’t hesitate to stop by this fascinating show!
Two of my favorite artists, Caleb Charland and Adam Ferriss are showing alongside Shannon Benine, Kimberly Burleigh, Christine Gray, Jenny Morgan, Bill Morrisson, Anna von Mertens and Ven Voisey.
The show runs from March 4 to April 6 in the University Gallery with a reception April 4 at 6 pm.
Gemini 11
Photos taken by astronauts Pete Conrad and Dick Gordon in September of 1966 during the Gemini XI mission.
Credit: NASA/JSC/Arizona State University
(Source: spaceplasma)
![Look carefully at the image above. The little blue dot outlined in the square is the Earth captured in an image by the Voyager 1 spacecraft from a distance of 6.4 billion kilometres (4 billion miles) on February 14, 1990.
Carl Sagan was one of the driving forces who pushed for the Voyager craft to take the shot, he gave the following quote on what he felt about about the image:
We succeeded in taking that picture [from deep space], and if you look at it, you see a dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors, so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light.
Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.](http://24.media.tumblr.com/0893cb3e08bd683bd311f8a038887888/tumblr_mgfs0rZ1JJ1qbhnpvo1_400.jpg)
