One of the most enduring tropes about crocodiles is to describe them as “living fossils”. They are cold, slow-moving, and scaly, so they look like how one might picture a dinosaur. Like many clichés, there is an element of truth to this comparison. The crocodiles from 200 million years ago look surprisingly like the ones we know today.
Around 55.5 million years ago, there was a time period with more than 5°C – 8 °C warmer global average temperature than today, which named “Paleocene-Eocene Thermal Maximum” (PETM). As a result, there were crocodiles and even crocodiles in the Arctic and the region was completely ice-free. Now, a new study suggests that if we keep burning fossil fuels at the current rate, the Earth will be again 8 degrees warmer within the next few hundred years. We are pumping 10 times more carbon into the atmosphere than when there were palm trees in the Arctic. We’re going to face another PETM-like event soon.
By studying lunar craters, scientists have discovered that asteroid impacts became more frequent about 290 million years ago. So was just a matter of time for dinosaurs to become extinct.
What if the Earth’s history (our planet’s age is approximately 4.54 billion years), compressed into just one year? @YearOnEarth just did that. At midnight on the 31st of December, Chris Jennings started a little project for the incoming year: tweeting the entirety of the geological history of the Earth, compressed into one year.
The result is an amazing timeline of the Earth’s history.
Back in December 1990, during its flyby of Earth, NASA’s Galileo spacecraft, which studied the planet Jupiter and its moons, as well as several other Solar System bodies, pointed its instruments towards Earth, at the urging of Carl Sagan. And, it has found evidence of life on our planet. This can be a key to detecting vegetation on exoplanets – which is key to a possible i
In a paper published in Nature, researchers wrote “The Galileo spacecraft found evidence of abundant gaseous oxygen, a widely distributed surface pigment with a sharp absorption edge in the red part of the visible spectrum, and atmospheric methane in extreme thermodynamic disequilibrium. Together, these are strongly suggestive of life on Earth.”
Around 66 million years ago, an asteroid or comet at least 10 kilometers (6 miles) in diameter impacted a few miles from the present-day town of Chicxulub in Mexico (hence it is dubbed as the “Chicxulub impactor”, the “dinosaur-killer”), at around 64,000 kilometers per hour (40,000 mph). The impact has created a crater (Chicxulub crater) more than 180 km (110 miles) in diameter. But, what’s more, the energy of the impact (which is equivalent of about ten billion Hiroshima atom bombs) vaporized the rock which was rich in sulfur compounds, filling the air with a thick cloud of dust, similar to that created by a catastrophic volcanic eruption.
Hint: they are all space rocks. But, there are some differences. The biggest difference between an asteroid and a comet, for example, is what they are made of.
I stumbled upon an amazing web page showing what did ancient Earth look like. On the “Dinosaur Pictures and Facts” web page (dinosaurpictures.org), there’s also an interactive animation. On this page, you can either select the years (i.e. 600 million years ago) or jump to a particular event (i.e. first multicellular life) and see how ancient Earth did look like then. You can also remove the clouds and stop the Earth’s rotation if you want to.
Are we alone in the Universe? Or do any other life forms exist out there? A new study, published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS, see notes 1) suggests that life emerged so early on Earth, so it should be widespread. In other words, the Universe should be filled with life.
The story goes back to the year 1982 when UCLA Scholar and Pioneer in Study of the Evolution of Life, J. William Schopf collected 3.465-billion-year-old fossils from the Apex Chert in
According to the scientists who drilled into the Chicxulub crater buried underneath the Yucatán Peninsula and the Gulf of Mexico, the dinosaur-killer asteroid hit the “worst possible place” (for the dinosaurs, of course). They summarized their findings so far in a BBC Two documentary titled “The Day The Dinosaurs Died”. The documentary was presented by professors Alice Roberts and Ben Garrod.
