Friday Headlines, September 2, 2016
THE LATEST IN THE GEOSCIENCES
Earth’s Oldest Fossils
First Stars Are Younger than We Thought
Little Bitty Pterosaur
Fossils that are arguably the oldest on Earth were recently described in a technical journal. Now, don’t get too excited. They’re not dinosaurs. Their not jellyfish.
Nope. They’re (probably) stromatolites, which are large masses of sediment and single-celled organisms (often algae) that form little stepping-stone like pedestals in watery environments.
Stromatolites still live today, such as these in Shark Bay, Australia.
In the fossil record, stromatolites look like wavy layered rocks, and can be identified as microbial in origin by isotopic analysis, among other techniques.
You can read the original technical paper, published in the journal Nature, here.
I admit, this one blew my mind a bit. But here goes.
See, after the Big Bang, it took a while for light and matter to become separate things. This makes sense if you think about light as both a wave and a particle. Light particles are objects just like matter is.
Then light and matter separated. Matter began to organize itself into atoms and light begins to bounce around. This light is observed as the Cosmic Microwave Background (CMB).
As matter condenses into knots, stars begin to form. These are the first stars. These first stars caused the reionization of all the other atoms in the universe.
The European Space Agency’s Planck satellite telescope is able to observe the edges of the universe, where the relationship between the CMB, the earliest stars, and the reionization can all be seen.
Through their observations, it has been determined that the first stars appeared about 700 million years after the Big Bang, and the universe was completely reionized by about 900 million years after the Big Bang.
Earlier studies had thought that the earliest stars formed earlier, at about 400 million years after the Big Bang. This new study then shows that the oldest stars are younger than we had originally thought.
We hear a lot about the biggest fossils. The largest tyrannosaur. The hugest sauropod.
The most enormous pterosaur, Quetzalcoatlus, always gets gasps as I describe it’s wingspan in class.
But they’re not all giants. This one is made of squee. Here is a new azhdarchid pterosaur, which is no bigger than a housecat.
You can read about this little guy in the journal Royal Society Open Science, here.