عربي English Türkçe اردو فارسى
Logo
Latest News
Varieties

Study Details Differences between Deep Interiors of Mars and Earth

An undated artist’s depiction of the Martian interior and the paths taken by seismic waves as they traveled through the planet’s core. (NASA/JPL and Nicholas Schmerr/Handout via Reuters)
An undated artist’s depiction of the Martian interior and the paths taken by seismic waves as they traveled through the planet’s core. (NASA/JPL and Nicholas Schmerr/Handout via Reuters)
TT
TT

Study Details Differences between Deep Interiors of Mars and Earth

An undated artist’s depiction of the Martian interior and the paths taken by seismic waves as they traveled through the planet’s core. (NASA/JPL and Nicholas Schmerr/Handout via Reuters)
An undated artist’s depiction of the Martian interior and the paths taken by seismic waves as they traveled through the planet’s core. (NASA/JPL and Nicholas Schmerr/Handout via Reuters)

Mars is Earth's next-door neighbor in the solar system - two rocky worlds with differences down to their very core, literally.

A new study based on seismic data obtained by NASA's robotic InSight lander is offering a fuller understanding of the Martian deep interior and fresh details about dissimilarities between Earth, the third planet from the sun, and Mars, the fourth.

The research, informed by the first detection of seismic waves traveling through the core of a planet other than Earth, showed that the innermost layer of Mars is slightly smaller and denser than previously known. It also provided the best assessment to date of the composition of the Martian core.

Both planets possess cores comprised primarily of liquid iron. But about 20% of the Martian core is made up of elements lighter than iron - mostly sulfur, but also oxygen, carbon and a dash of hydrogen, the study found. That is about double the percentage of such elements in Earth's core, meaning the Martian core is considerably less dense than our planet's core - though more dense than a 2021 estimate based on a different type of data from the now-retired InSight.

"The deepest regions of Earth and Mars have different compositions - likely a product both of the conditions and processes at work when the planets formed and of the material they are made from," said seismologist Jessica Irving of the University of Bristol in England, lead author of the study published this week in the journal Proceedings of the National Academy of Sciences.

The study also refined the size of the Martian core, finding it has a diameter of about 2,212-2,249 miles (3,560-3,620 km), approximately 12-31 miles (20-50 km) smaller than previously estimated. The Martian core makes up a slightly smaller percentage of the planet's diameter than does Earth's core.

The nature of the core can play a role in governing whether a rocky planet or moon could harbor life. The core, for instance, is instrumental in generating Earth's magnetic field that shields the planet from harmful solar and cosmic particle radiation.

"On planets and moons like Earth, there are silicate - rocky - outer layers and an iron-dominated metallic core. One of the most important ways a core can impact habitability is to generate a planetary dynamo," Irving said.

"Earth's core does this but Mars' core does not - though it used to, billions of years ago. Mars' core likely no longer has the energetic, turbulent motion which is needed to generate such a field," Irving added.

Mars has a diameter of about 4,212 miles (6,779 km), compared to Earth's diameter of about 7,918 miles (12,742 km), and Earth is almost seven times larger in total volume.

The behavior of seismic waves traveling through a planet can reveal details about its interior structure. The new findings stem from two seismic events that occurred on the opposite side of Mars from where the InSight lander - and specifically its seismometer device - sat on the planet's surface.

The first was an August 2021 marsquake centered close to Valles Marineris, the solar system's largest canyon. The second was a September 2021 meteorite impact that left a crater of about 425 feet (130 meters).

The US space agency formally retired InSight in December after four years of operations, with an accumulation of dust preventing its solar-powered batteries from recharging.

"The InSight mission has been fantastically successful in helping us decipher the structure and conditions of the planet's interior," University of Maryland geophysicist and study co-author Vedran Lekic said. "Deploying a network of seismometers on Mars would lead to even more discoveries and help us understand the planet as a system, which we cannot do by just looking at its surface from orbit."

Most Viewed

 
 
Varieties

17th Century Wreck Reappears from Stockholm Deep

The remains of a 17th century shipwreck is pictured after resurfacing in Stockholm, Sweden, on February 17, 2026. (Photo by Jonathan NACKSTRAND / AFP)
The remains of a 17th century shipwreck is pictured after resurfacing in Stockholm, Sweden, on February 17, 2026. (Photo by Jonathan NACKSTRAND / AFP)
TT
TT

17th Century Wreck Reappears from Stockholm Deep

The remains of a 17th century shipwreck is pictured after resurfacing in Stockholm, Sweden, on February 17, 2026. (Photo by Jonathan NACKSTRAND / AFP)
The remains of a 17th century shipwreck is pictured after resurfacing in Stockholm, Sweden, on February 17, 2026. (Photo by Jonathan NACKSTRAND / AFP)

A 17th century Swedish Navy shipwreck buried underwater in central Stockholm for 400 years has suddenly become visible due to unusually low Baltic Sea levels.

The wooden planks of the ship's well-preserved hull have since early February been peeking out above the surface of the water off the island of Kastellholmen, providing a clear picture of its skeleton.

"We have a shipwreck here, which was sunk on purpose by the Swedish Navy," Jim Hansson, a marine archeologist at Stockholm's Vrak - Museum of Wrecks, told AFP.

Hansson said experts believe that after serving in the navy, the ship was sunk around 1640 to use as a foundation for a new bridge to the island of Kastellholmen.

Archeologists have yet to identify the exact ship, as it is one of five similar wrecks lined up in the same area to form the bridge, all dating from the late 16th and early 17th centuries.

"This is a solution, instead of using new wood you can use the hull itself, which is oak" to build the bridge, Hansson said.

"We don't have shipworm here in the Baltic that eats the wood, so it lasts, as you see, for 400 years," he said, standing in front of the wreck.

Parts of the ship had already broken the surface in 2013, but never before has it been as visible as it is now, as the waters of the Baltic Sea reach their lowest level in about 100 years, according to the archaeologist.

"There has been a really long period of high pressure here around our area in the Nordics. So the water from the Baltic has been pushed out to the North Sea and the Atlantic," Hansson explained.

A research program dubbed "the Lost Navy" is underway to identify and precisely date the large number of Swedish naval shipwrecks lying on the bottom of the Baltic.

Varieties

China Has Slashed Air Pollution, but the ‘War’ Isn’t Over 

This picture taken on February 11, 2026 shows pedestrians walking along an overpass as traffic snarls in Beijing. (AFP)
This picture taken on February 11, 2026 shows pedestrians walking along an overpass as traffic snarls in Beijing. (AFP)
TT
TT

China Has Slashed Air Pollution, but the ‘War’ Isn’t Over 

This picture taken on February 11, 2026 shows pedestrians walking along an overpass as traffic snarls in Beijing. (AFP)
This picture taken on February 11, 2026 shows pedestrians walking along an overpass as traffic snarls in Beijing. (AFP)

Fifteen years ago, Beijing's Liangma riverbanks would have been smog-choked and deserted in winter, but these days they are dotted with families and exercising pensioners most mornings.

The turnaround is the result of a years-long campaign that threw China's state power behind policies like moving factories and electrifying vehicles, to improve some of the world's worst air quality.

Pollution levels in many Chinese cities still top the World Health Organization's (WHO) limits, but they have fallen dramatically since the "airpocalypse" days of the past.

"It used to be really bad," said Zhao, 83, soaking up the sun by the river with friends.

"Back then when there was smog, I wouldn't come out," she told AFP, declining to give her full name.

These days though, the air is "very fresh".

Since 2013, levels of PM2.5 -- small particulate that can enter the lungs and bloodstream -- have fallen 69.8 percent, Beijing municipality said in January.

Particulate pollution fell 41 percent nationwide in the decade from 2014, and average life expectancy has increased 1.8 years, according to the University of Chicago's Air Quality Life Index (AQLI).

China's rapid development and heavy coal use saw air quality decline dramatically by the 2000s, especially when cold winter weather trapped pollutants close to the ground.

There were early attempts to tackle the issue, including installing desulphurization technology at coal power plants, while factory shutdowns and traffic control improved the air quality for events like the 2008 Olympics.

But the impact was short-lived, and the problem worsened.

- Action plan -

Public awareness grew, heightened by factors like the US embassy in Beijing making monitoring data public.

By 2013, several international schools had installed giant inflatable domes around sport facilities to protect students.

That year, multiple episodes of prolonged haze shrouded Chinese cities, with one in October bringing northeastern Harbin to a standstill for days as PM2.5 levels hit 40 times the WHO's then-recommended standard.

The phrase "I'm holding your hand, but I can't see your face" took off online.

Later that year, an eight-year-old became the country's youngest lung cancer patient, with doctors directly blaming pollution.

As concerns mounted, China's ruling Communist Party released a ten-point action plan, declaring "a war against pollution".

It led to expanded monitoring, improved factory technology and the closure or relocation of coal plants and mines.

In big cities, vehicles were restricted and the groundwork was laid for widespread electrification.

For the first time, "quantitative air quality improvement goals for key regions within a clear time limit" were set, a 2016 study noted.

These targets were "the most important measure", said Bluetech Clean Air Alliance director Tonny Xie, whose non-profit worked with the government on the plan.

"At that time, there were a lot of debates about whether we can achieve it, because (they were) very ambitious," he told AFP.

The policy targeted several key regions, where PM2.5 levels fell rapidly between 2013 and 2017, and the approach was expanded nationwide afterwards.

"Everybody, I think, would agree that this is a miracle that was achieved in China," Xie said.

China's success is "entirely" responsible for a decline in global pollution since 2014, AQLI said last summer.

- 'Low-hanging fruits' gone -

Still, in much of China the air remains dangerous to breathe by WHO standards.

This winter, Chinese cities, including financial hub Shanghai, were regularly among the world's twenty most polluted on monitoring site IQAir.

Linda Li, a running coach who has lived in both Beijing and Shanghai, said air quality has improved, but she still loses up to seven running days to pollution in a good month.

A top environment official last year said China aimed to "basically eliminate severe air pollution by 2025", but the government did not respond when AFP asked if that goal had been met.

Official 2025 data found nationwide average PM2.5 concentrations decreased 4.4 percent on-year.

Eighty-eight percent of days featured "good" air quality.

However, China's current definition of "good" is PM2.5 levels of under 35 micrograms per cubic meter, significantly higher than the WHO's recommended five micrograms.

China wants to tighten the standard to 25 by 2035.

The last five years have also seen pollution reduction slow.

The "low-hanging fruits" are gone, said Chengcheng Qiu from the Center for Research on Energy and Clean Air (CREA).

Qiu's research suggests pollution is shifting west as heavy industry relocates to regions like Xinjiang, and that some cities in China have seen double-digit percentage increases in PM2.5 in the last five years.

"They can't just stop all industrial production. They need to find cleaner ways to produce the output," Qiu said.

There is hope for that, given China's status as a renewable energy powerhouse, with coal generation falling in 2025.

"Cleaner air ultimately rests on one clear direction," said Qiu.

"Move beyond fossil fuels and let clean energy power the next stage of development."

Varieties

Sydney Man Jailed for Mailing Reptiles in Popcorn Bags 

Investigators recovered 101 Australian reptiles from parcels destined for Hong Kong, South Korea, Sri Lanka and Romania. (AFP file)
Investigators recovered 101 Australian reptiles from parcels destined for Hong Kong, South Korea, Sri Lanka and Romania. (AFP file)
TT
TT

Sydney Man Jailed for Mailing Reptiles in Popcorn Bags 

Investigators recovered 101 Australian reptiles from parcels destined for Hong Kong, South Korea, Sri Lanka and Romania. (AFP file)
Investigators recovered 101 Australian reptiles from parcels destined for Hong Kong, South Korea, Sri Lanka and Romania. (AFP file)

A Sydney man who tried to post native lizards, dragons and other reptiles out of Australia in bags of popcorn and biscuit tins has been sentenced to eight years in jail, authorities said Tuesday.

The eight-year term handed down on Friday was a record for wildlife smuggling, federal environment officials said.

A district court in Sydney gave the man, 61-year-old Neil Simpson, a non-parole period of five years and four months.

Investigators recovered 101 Australian reptiles from seized parcels destined for Hong Kong, South Korea, Sri Lanka and Romania, the officials said in a statement.

The animals -- including shingleback lizards, western blue-tongue lizards, bearded dragons and southern pygmy spiny-tailed skinks -- were posted in 15 packages between 2018 and 2023.

"Lizards, skinks and dragons were secured in calico bags. These bags were concealed in bags of popcorn, biscuit tins and a women's handbag and placed inside cardboard boxes," the statement said.

The smuggler had attempted to get others to post the animals on his behalf but was identified by government investigators and the New South Wales police, it added.

Three other people were convicted for taking part in the crime.

The New South Wales government's environment department said that "the illegal wildlife trade is not a victimless crime", harming conservation and stripping the state "and Australia of its unique biodiversity".