Nature & Biology

Comets or volcanoes? Scientists are changing their minds about how the Earth’s water got here

Comets or volcanoes? Scientists are changing their minds about how the Earth’s water got here

The Earth has been the blue planet for as many as 3.8 billion years. Ancient sedimentary rock deposits and lava that cooled into characteristic pillow shapes provide irrefutable evidence that liquid water has existed at the Earth’s surface for at least this long. But given how many barren rocks there are in the galaxy, Earth’s abundant oceans raise the question of where all that water came from.

The evidence that shows dinosaurs were in decline for 40 million years before the asteroid hit

When the dinosaurs were wiped off the face of the planet, how did they leave? Was it a slow, plodding decline or a short sharp bang? Back in the 1960s and 1970s, debate about this question was mainly taking place on the ground, at fossil sites in places like Montana. Paleontologist Robert Sloan and his colleagues documented evidence for the long-term decline of dinosaurs over a 10m to 20m-year period. Dinosaurs had been losing out, ever so slowly, to the rising mammals, mainly as a result of cooling climates.

What Is An Ice Age

Scientists have known for some time that the Earth goes through cycles of climatic change. Owing to changes in Earth’s orbit, geological factors, and/or changes in Solar output, Earth occasionally experiences significant reductions in its surface and atmospheric temperatures. This results in long-term periods of glaciation, or what is more colloquially known as an “ice age”.

Why were there so many dinosaur species?

Why were there so many dinosaur species?

A new species of dinosaur is described, on average, every ten days. As many as 31 species have already been reported this year and we can expect a few more before 2016 is over. Of course, figuring out what counts as a distinct species is a tricky problem. Palaeontologists are argumentative by nature, so getting any two of them to agree on a definitive list of species is probably impossible. But by anyone’s count, there were a lot of them – 700 or 800 that we know of, probably thousands in total. So how did the dinosaurs become so diverse?

What Is The World's Deepest Ocean?

What Is The World's Deepest Ocean?

One look at planet Earth on a map, or based on an image taken from space, ought to convey just how immense and important our oceans are. After all, they cover 72% of the planet’s surface, occupy a total volume of around 1.35 billion cubic kilometers (320 million cu mi), and are essential to life as we know it. And in their great depths, many mysteries still wait to be discovered.

What Is The Wettest Place On Earth?

What Is The Wettest Place On Earth?

Those who live along the “wet coast” – which is what people living in Puget Sound or the lower mainland of British Columbia and Vancouver Island affectionately call their home – might think that they live in the wettest place on Earth. Then again, people living in the Amazon rain forest might think that there lush and beautiful home is the dampest place in the world.

To bee or not to bee – why some insects pretend to be dangerous

To bee or not to bee – why some insects pretend to be dangerous

In the summer of 2011, panic gripped a small community in Gatineau, Quebec. Hundreds of small, striped insects were buzzing around a children’s playground. The playground was evacuated and entomologists were called in to establish whether or not the animals were dangerous. The answer was no, but it is easy to see why local residents were concerned. The animals that had taken up residence in the playground were hoverflies, a family of harmless fly species that have built up quite an arsenal of tricks to convince would-be predators that they are dangerous.

What Is The Temperature Of The Earth's Crust?

What Is The Temperature Of The Earth's Crust?

As you may recall learning in geology class, the Earth is made up of distinct layers. The further one goes towards the center of the planet, the more intense the heat and pressure becomes. Luckily, for those of us living on the crust (the outermost layer, where all life lives) the temperature is relatively steady and pleasant.

In fact, one of the things that makes planet Earth habitable is the fact that the planet is close enough to our Sun to receive enough energy to stay warm. What’s more, its “surface temperatures” are warm enough to sustain liquid water, the key to life as we know it. But the temperature of Earth’s crust also varies considerably depending on where and when you are measuring it.

A 400-year-old shark is the latest animal discovery to reveal the secrets of long life

A 400-year-old shark is the latest animal discovery to reveal the secrets of long life

With an estimated lifespan of 400 years, the Greenland shark has just been reported to be the longest-lived vertebrate on the planet. This is only the latest of a series of recent findings that push the boundaries of animal longevity, and it raises the perennial question of what factors enable some animals to achieve what we might call extreme longevity – lifespans that can be measured in centuries.