Science

The largest stegosaurus skeleton ever found, nicknamed Apex, sold for a record breaking $44.6 million at auction in New York on Wednesday, Sotheby's said.

Estimated to be 150 million years old, Apex is said to be "among the most complete skeletons ever found," according to the auction house.

Have you tried manifesting? It’s hard to escape on social media – the idea that you can will what you desire into reality through the power of belief. This could be financial success, romantic love or sporting glory.

Singer Dua Lipa, who headlined Glastonbury festival in June 2024, has said that performing on Friday night at the festival was “on her dream board”. “If you’re manifesting out there, be specific – because it might happen!”

Manifesting gained popularity quickly during the pandemic. By 2021, the 3-6-9 manifestation method was famous. A TikTok viewed over a million times, for instance, explains this “no fail manifesting technique”. You write down what you want three times in the morning, six times in the afternoon and nine times before you go to bed and repeating until it comes true. Now, content creators are explaining countless methods to speak your dreams into reality.

But the idea that if you wish for something hard enough it will happen isn’t new. It grew out of the self-help movement. Some early popular books that peddled this idea include Napoleon Hill’s Think and Grow Rich from as long ago as 1937, and Louise Hay’s You Can Heal Your Life from 1984.

At first glance, the 2024 remake movie Twisters contains many of the ingredients of the 1996 original, which starred Helen Hunt and Bill Paxton: a catastrophic and rare weather event, the urgency to use new technology to understand it, and central characters battling personality clashes.

However, Twisters (on general release from July 17) does more than confirm Hollywood’s interest in money-making sequels. It suggests movie financiers are convinced that people are fascinated by extreme weather and the devastation it can cause. And they’re right.

Earlier this month, drugs sold as cocaine in Melbourne were found to be contaminated with a powerful group of opioids, known as nitazenes.

These new synthetic drugs were also the suspected cause of four people being hospitalised in Sydney in May. And in April, nitazenes were found in drugs used by around 20 people who overdosed in outer Sydney.

Seagrass, a marine plant that flowers underwater, has lots of environmental benefits – from storing carbon to preventing coastal erosion. This 3D habitat is often a haven for wildlife but, with so many seagrass restoration projects now happening globally, success can be hard to quantify.

In this episode of The Conversation Weekly podcast, we speak to Isabel Key, a marine ecologist at the University of Edinburgh in the UK, about her work recording the soundscape of Scottish seagrass meadows to uncover more about the creatures living within them. She also explains how this is the first step in the development of a seagrass sound library and potentially even artificial intelligence tools that could help us better understand the sounds of the sea.

Milwaukee (AFP) – Climate change is little more than an afterthought for attendees at the Republican National Convention, who are gathered this week to crown Donald Trump as their party's nominee for this November's election.

"I don't believe all that," said Jack Prendergast, from New York, who believes that human activity does just as much harm to the planet as "when a volcano goes off."

Apart from the Sun, its planets and their moons, our Solar System has vast amounts of space rocks – fragments left over from the formation of the inner planets.

A large concentration of asteroids forms a vast ring around our Sun, orbiting it between Mars and Jupiter. Fittingly, it’s called the main asteroid belt. Comets are icy bodies of dust and rocks that originated even farther away – in the Kuiper Belt beyond Neptune and the Oort Cloud of debris surrounding the Solar System.

Extraterrestrial rocks come in many sizes. Generally speaking, asteroids are space rocks larger than one metre, while the smaller pieces (from two millimeters up to one meter in size) are known as meteoroids.

Regardless of where they come from, once these foreign rocks make it to Earth’s surface, we call them meteorites. But they are much more than just simple rocks from far, far away.

They have allowed us to estimate the age of our planet, and changed the course of evolution more than once. Here are six major ways meteorites and comets have contributed to Earth’s history or our knowledge of it.

1. The age of our planet

About 4.5 billion years ago, a Mars-sized planet collided with the proto-Earth, changing the composition of our planet and forming our Moon.

During its first tens of millions of years, Earth was predominantly molten. It was too hot to form solid minerals and rocks, so the exact age of our planet remains unknown. But we do know it’s between the age measured from meteorites and the age of the oldest rocks we have been able to find and date.

The oldest minerals that have been reliably dated on Earth are tiny zircon grains found in Western Australia. The oldest one is 4.4 billion years old. However, scientists have also dated specks of calcium and aluminum found in meteorites, which yielded an older age of 4.56 billion years – the age of our Solar System.

So, thanks in part to the oldest age provided by a meteorite, our best estimate is that Earth formed around 4.54 billion years ago.

A slab of the Allende meteorite, the best-studied meteorite in history. It has many calcium–aluminum-rich inclusions dated to be 4.567 billion years old – the oldest known solids to have formed in the Solar System. Shiny Things/Flickr, CC BY-NC

2. The building blocks of life

The most plausible theory for the beginning of life on Earth is based on simple organic compounds that formed in space and were brought to Earth by meteorites and other celestial bodies.

During the Late Heavy Bombardment, a period between 4.1 and 3.8 billion years ago when more impact events hammered our planet, Earth’s surface was partially solid.

Amino acids, hydrocarbons and other carbon-based molecules arrived at our planet in carbonaceous chondrites (primitive meteorites, remnants from the early Solar System) and comets.

Once the early Earth was enriched with these organic molecules, chemical evolution followed. Eventually, life emerged on our planet. The earliest evidence is potential microbial life from 3.8 billion years ago, not long after the Late Heavy Bombardment.

Regardless of how life started, all theories agree on the need for a primitive ocean – or pools of water – that allowed early life on Earth to develop.

Photomicrograph of an ordinary chondrite meteorite found in northwestern Africa containing small spherical particles of minerals called chondrules. Circled is a barred olivine chondrule. Francisco Testa/From the author's personal collection

3. How we got our oceans

Meteorites and comets also played a major role in the formation of Earth’s oceans and atmosphere. Large quantities of water were delivered to our planet during the Late Heavy Bombardment.

In addition, water was released from Earth’s interior through volcanic activity during the Hadean Eon, the first eon in our planet’s history.

Water vapor, along with other gases such as carbon dioxide, methane, ammonia, nitrogen and sulphur, formed the proto-atmosphere. Rain began to fall once the temperature dropped below the boiling point of water, forming our primordial ocean.

Yes – the water we drink today is at least partly of extraterrestrial origin.

4. Changing the course of evolution

The extinction of dinosaurs happened about 66 million years ago. It’s linked to the second-largest known meteorite impact on Earth, the deeply buried Chicxulub crater in Mexico.

In contrast, the Late Devonian extinction about 380 to 360 million years ago cannot be explained by a single impact. Several factors have been proposed as potential causes, including multiple impacts, climate change, depletion of oxygen (anoxia) in the oceans and volcanic activity.

Repeated times during Earth’s history, impact events have influenced the survival and evolution of life on our planet.

The subtle impression of the Chicxulub impact crater is still visible on the Yucatán peninsula in Mexico today. NASA/JPL

5. Sampling Earth’s deep mantle and core

Scientists use a combination of methods to understand Earth’s internal structure: crust, mantle, core and their subdivisions. Seismology is the most important of them, which studies the propagation of seismic waves generated by earthquakes or artificial sources through Earth’s interior.

We have access to rock samples from the crust and upper mantle, but we will never be able to sample the deep mantle or solid core. Even if we had the technology, it would be astronomically expensive, and going down to such depths involves extreme pressures and temperatures.

Since direct sampling is impossible, scientists rely on indirect methods.

Pallasites and metallic meteorites are rocks from differentiated asteroids – ones that also have a mantle and core. Such space rocks are the closest we will ever come to sampling the deepest portions of our own planet. They help us understand its composition.

Pallasites are rare, and contain a silicate mineral called olivine embedded in nickel-iron alloys. It’s thought pallasites form in the boundary between the core and mantle-like regions of differentiated asteroids.

Metallic or iron meteorites are mainly composed of the nickel-iron alloys kamacite and taenite. They are the core fragments of differentiated asteroids, giving us clues to our own planet’s core.

Slab of Aletai iron meteorite, found in Xinjiang, China in 1898. Francisco Testa/From the author's personal collection

6. Meteorite impacts gave us huge gold and nickel deposits

The Witwatersrand rocks in South Africa host the world’s largest known gold reserves. This would not be the case without the Vredefort impact crater – the largest known impact structure on Earth – formed about 2.02 billon years ago.

The impact saved these gold deposits from erosion by covering the entire area with ejected material, concealing the ore-bearing layers beneath. If an ore deposit erodes, the material disperses and it wouldn’t make for profitable extraction.

Witwatersrand is the largest gold-producing district in the world. Which means the ancient meteorite impact has made an indirect, lasting impact on our society through the availability of this precious metal.

But that’s not the only such event. The third-largest known impact crater on Earth is the Sudbury Basin in Canada, formed 1.85 billion years ago. It hosts giant nickel deposits because the impact disrupted Earth’s crust, partially melting it and allowing magma from the mantle to rise.

This led to the accumulation of nickel, copper, palladium, platinum and other metals, producing one of the richest mining districts on the planet.

It's well known that as far as the climate crisis goes, time is of the essence.

Now a study out Monday shows that the melting of the polar ice caps is causing our planet to spin more slowly, increasing the length of days at an "unprecedented" rate.

People are living longer lives compared to previous generations but, over the last few decades, there has been a hidden shift — they are passing away at increasingly similar ages.

This is a trend captured by the Gini Index, also called the Gini Coefficient. Should everyone pass away at the same age, the Gini Index would be zero. This makes the Gini Index a measure of equality, and a Gini Index of one represents inequality.

There is often much debate about who is the greatest among sportsmen and women, movie stars, leaders or artists. But some scholars have truly made a staggering difference to the world.

Winning a Nobel prize is a rare, extraordinary achievement, but five remarkable people have done it twice. Who are they? What sets them apart? And who is the greatest?

Most adults never have to take an IQ test. But tests for assessing students’ cognitive abilities, such as the cognitive ability test (Cat), are used in schools around the world. These tests are very similar to IQ tests. Taking them may be a pain for kids. Possibly, it’s an even bigger pain for parents.

Just for a moment, put yourself in the shoes of a parent whose child’s overall Cat score turns out to be below average. A flock of unpleasant questions may pop into your mind. Does that mean they won’t get into a top university? And what about their career?

Storm-chasing for science can be exciting and stressful – we know, because we do it. It has also been essential for developing today’s understanding of how tornadoes form and how they behave.

In 1996 the movie “Twister” brought storm-chasing into the public imagination as scientists played by Helen Hunt and Bill Paxton raced ahead of tornadoes to deploy their sensors and occasionally got too close. That movie inspired a generation of atmospheric scientists.