The four missing military personnel who are presumed dead after a helicopter crash off the Queensland coast are being remembered by their colleagues, family, friends and government for their service.

Defence minister Richard Marles said "significant wreckage" of the MRH-90 Taipan aircraft has been discovered after the helicopter went down near Lindeman Island, which is near Hamilton Island, at about 11pm on Friday during the Talisman Sabre military exercises

Those onboard and missing were identified yesterday as Captain Daniel Lyon, Lieutenant Maxwell Nugent, Corporal Alexander Naggs, and Warrant Officer Joseph Laycock.

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"With every passing hour, it is now clear any hope of finding Captain Lyon, Lieutenant Nugent, Corporal Naggs and Warrant Office Laycock alive has been lost," Marles said.

"The tragedies that have taken place in the Whitsundays have transferred from those being of search and rescue to an activity of recovery."

Marles said there will be a full and thorough investigation into the crash but for now, the government and defence force stands with the families of the men.

"They will spend the rest of our lives with an unfavourable hole," Marles said.

"To them, we are so deeply sorry and so grateful.

"They have every right to feel an intense sense of pride.

"Amidst the inadequacy of these words that, I wanted to know they stand in the warm embrace of the entire nation."

Marles said defence exercises are serious and carry a "dangerous" risk but play a "critical part in providing for the collective security and peace of the region in which we live".

Marles said the helicopters were certified to fly but in the meantime have been grounded while the investigation is underway.

"In the meantime, our fleet of MRH-90s have been grounded and they will not fly again until we understand what has happened and we have modified or acted accordingly," he said.

Chief of the Defence Force General Angus Campbell said the return of the Taipans will form part of the aviation investigation.

"There is going to be an investigation is there always would be, and it will be utterly thorough, and consider all factors, but we must not speculate and we must not in any way influence or distort the presumptions of that investigation," he said.

Tributes to remember the four military personnel killed

Queensland MP Phillip Thompson, who served with Corporal Naggs in the First Battalion Royal Australian Regiment, said his thoughts, prayers and heart go out to his family.

"He was a happy guy, a great person, he was someone who was never too hard for anything," he said.

"A life of service. He was someone if you asked a question you'd get an answer.

"He's one of the nicest blokes I've ever met."

In the flux of tributes by government and ADF officials, Governor-General David Hurley extended his sympathy to the loved ones and colleagues of the four men.

"As they stepped forward to serve us, so must we to honour their memory, remember their sacrifice and support their families," he said.

"It is a tragedy, and Linda and my thoughts are with the families, friends and other defence force personnel at this difficult time. I hope that the knowledge of our nation's gratitude is of some comfort in this moment of intense grief."

Former ADF-member-turned-politician Jacqui Lambie said her heart goes out to the families of the four men.

"To the defence community out there, I just want you to know that you have the country behind you," she said.

"We are thinking of you."

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Search for bodies underway as MRH-90s reviewed

The search for the MRH-90 and the four aviators from the 6th aviation regiment based at the Holsworthy army barracks in Sydney is now a recovery effort.

An exclusion zone of more than 100 square kilometres is in place off the coast.

Campbell said authorities will do everything possible to bring the men's bodies home to their families.

The crash marks one of Australia's worst peacetime military disasters in almost 20 years, and came as the aircraft was being phased out of military use.

The decision to discontinue their use was made after one went down off the coast of New South Wales near Jervis Bay in March. Ten people were on-board, but all managed to make their way out.

The fleet was also grounded then but returned to the skies in April with "risk mitigations" in place, a Defence spokesperson said at the time.

Marles said the MRH-90s were due to come out of service at the end of next year in favour of Blackhawk aircraft.

"We will move through the process of putting the Blackhawks into service as quickly as we can, but as thoroughly as we need to, and we will not be finding MRH-90s until we understand what has happened," he said.

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Prime Minister Anthony Albanese said earlier it was a reminder that there were no "safe and easy days" for people in the military.

Albanese offered his condolences to the families of the victims, who he said were trying to "build a more peaceful and safe world" during the failed operation.

"On behalf of our nation, our thoughts and prayers are with the families, friends and colleagues of those who are missing," he said.

"Our thoughts are also with those that they serve alongside – friends, brothers and sisters in uniform who even now are aiding in the search effort. I'd also like to thank the support from other nations during this search effort".

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The defence has opened its case in Christchurch.

A mysterious item found washed up on a beach near Jurien Bay in Western Australia earlier this month is likely space junk from an Indian rocket.

The acorn-shaped object stunned authorities when it washed ashore at Green Head, about 220 kilometres north of Perth on June 16.

The Australian Space Agency believe the object was most likely debris from an "expended third-stage of a Polar Satellite Launch Vehicle".

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In a statement, the agency said medium-lift launch vehicle was operated by the Indian Space Research Organisation (ISRO).

"The debris remains in storage and the Australian Space Agency is working with ISRO, who will provide further confirmation to determine next steps, including considering obligations under the United Nations space treaties," the agency said.

Space lawyer and professor Melissa de Zwart told 9news.com.au last week that the object was a unique discovery.

"It is quite amazing that something this large has washed up," she said.

"It's quite interesting that this has happened."

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Although it's pretty rare, space junk has been found scattered across Australia over the past years.

In October last year, rocket fragments linked to SpaceX were discovered in the NSW Snowy Mountains.

NASA believes there are about 100 million pieces of debris orbiting the earth that are smaller than a millimetre and about 23,000 pieces larger than a softball.

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High-efficiency particulate air (HEPA) filters improve air quality by up to 30–74 per cent during bushfire events, according to a new study from CSIRO

A royal commission into Black Summer heard smoke associated with the fires was linked to the additional deaths of 450 people.

But new research from Australia's national science agency, published today in Public Health Research & Practice HEPA filters could help protect the 2.7 million Australians affected by asthma during extreme smoke events.

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Lead author and CSIRO scientist Dr Amanda Wheeler said using the filters inside homes could help provide protection against sources of "any smoke emission".

"Staying inside and closing windows and doors during extreme smoke events is important, but ultimately what provides protection against smoke pollution indoors are air purifiers fitted with HEPA filters," Wheeler said.

"Using more than one, if possible, inside houses is likely to lead to improved health outcomes.

"While the research was focussed on prescribed burns, the findings are relevant for protection during bushfire events more generally.

"They demonstrate that any smoke emissions, including from neighbouring houses' wood heaters can be managed better."

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The study came to its conclusion by monitoring indoor and outdoor concentrations of fine particulate matter, or PM2.5, during prescribed burning periods.

Until now there has been limited evidence air purifiers fitted with HEPA filters reduce exposure or health risks associated with PM2.5.

Wheeler said bushfires are the greatest threat to air quality in the country, and added that climate change is only increasing the complexity of bushfire mitigation.

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"Prescribed burns are an important part of fire management, but outdoor smoke can easily infiltrate homes and buildings, so it's critical that we find ways to protect populations from serious health impacts," she said.

Her comments mirror that of Former NSW Fire and Rescue Commissioner Greg Mullin, who told 9news.com.au bushfire seasons in Australia have extended because of climate change – and can now occur simultaneously across states.

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WARNING: Aboriginal and Torres Strait Islander readers are advised that this article contains an image of a person who has died.

Four people accused of fatally bashing Indigenous Perth schoolboy Cassius Turvey will have to wait until 2025 to stand trial for murder.

Cassius, a 15-year-old Noongar Yamatji teenager, was allegedly chased down and attacked with a metal pole as he walked home from school with friends on October 13 last year.

He suffered serious head injuries and died in hospital 10 days later, triggering an outpouring of grief and anger across the nation, with some Indigenous leaders condemning the alleged assault as cowardly and racist.

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Brodie Lee Palmer, 28, Mitchell Colin Forth, 25, Jack Steven James Brearley, 22, and Aleesha Louise Gilmore, 21, pleaded not guilty to murder in May.

They appeared on Monday via video and audio link in the Supreme Court in Perth where Justice Joseph McGrath provisionally listed their trial for February 10.

It's expected to run for eight weeks until April 7 due to the large amount of evidence the Crown is expected to present against the group, including CCTV footage.

Prosecutor Ben Stanwix said it expected to file the brief of evidence next week.

Palmer, Forth and Gilmore were remanded in custody until October 26 when they will reappear for a status conference.

Brearley is scheduled to apply for bail later on Monday.

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He and Forth, and another man named Ethan Robert MacKenzie, 19, are also accused of unlawfully detaining and wounding another 15-year-old boy in the days before Cassius was attacked.

Gilmore has been charged with unlawfully detaining the same teen.

MacKenzie will stand trial at the same time as the other accused.

Brearley, Forth and Palmer have also denied assaulting and stealing a baseball cap and crutches from another teen on the same day as Cassius was allegedly attacked. Gilmore is accused of assaulting the same boy and pleaded not guilty.

Brearley appeared from Casuarina Prison in Perth's south and Palmer, Forth and MacKenzie appeared from Hakea Prison. Gilmore was in Greenough Regional Prison, about 400km north of Perth.

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Brearley was charged in October, before Palmer, Forth, MacKenzie and Gilmore were charged in January.

Cassius has been remembered as a loving son and a role model to his friends. He had started his own lawn-mowing business and was invited at age 11 to deliver an acknowledgement of country at the WA parliament.

Some members of his family attended court on Monday but they declined to speak to media.

For 24/7 crisis support run by Aboriginal and Torres Strait Islander people, contact 13YARN (13 92 76).

Since the start of July the records have been tumbling, one-by-one.

As the Northern Hemisphere swelters under a record-breaking summer heat wave, much further south, in the depths of winter, another terrifying climate record is being broken.

Antarctic sea ice has fallen to unprecedented lows for this time of year.

Every year, Antarctic sea ice shrinks to its lowest levels towards the end of February, during the continent's summer.

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The sea ice then builds back up over the winter.

But this year scientists have observed something different.

The sea ice has not returned to anywhere near expected levels.

In fact it is at the lowest levels for this time of year since records began 45 years ago.

The ice is around 1.6 million square kilometres below the previous winter record low set in 2022, according to data from the National Snow and Ice Data Centre.

In mid-July, Antarctica's sea ice was 2.6 million square kilometres below the 1981 to 2010 average.

That is an area the same size as Western Australia.

'The game has changed'

The phenomenon has been described by some scientists as off-the-charts exceptional – something that is so rare, the odds are that it only happens once in millions of years.

But Ted Scambos, a glaciologist at the University of Colorado Boulder, said that speaking in these terms may not be that helpful.

"The game has changed," he said.

"There's no sense talking about the odds of it happening the way the system used to be, it's clearly telling us that the system has changed."

Scientists are now scrambling to figure out why.

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The Antarctic is a remote, complex continent.

Unlike the Arctic, where sea ice has been on a consistently downwards trajectory as the climate crisis accelerates, sea ice in the Antarctic has swung from record highs to record lows in the last few decades, making it harder for scientists to understand how it is responding to global heating.

But since 2016, scientists have begun to observe a steep downwards trend.

While natural climate variability affects the sea ice, many scientists say climate change may be a major driver for the disappearing ice.

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"The Antarctic system has always been highly variable," Scambos said.

"This [current] level of variation, though, is so extreme that something radical has changed in the past two years, but especially this year, relative to all previous years going back at least 45 years."

Several factors feed into sea ice loss, he said, including the strength of the westerly winds around Antarctica, which have been linked to the increase of planet-heating pollution.

"Warmer ocean temperatures north of the Antarctic Ocean boundary mixing into the water that's typically somewhat isolated from the rest of the world's oceans is also part of this idea as to how to explain this," he said.

In late February of this year, Antarctic sea ice reached its lowest extent since records began.

This winter's unprecedented occurrence may indicate a long-term change for the isolated continent, Scambos said.

"It is more likely than not that we won't see the Antarctic system recover the way it did, say, 15 years ago, for a very long period into the future, and possibly ever."

Others are more cautious.

"It's a large departure from average but we know that Antarctic sea ice exhibits large year to year variability," Julienne Stroeve, a senior scientist at the National Snow and Ice Data Centre said, adding "it's too early to say if this is the new normal or not."

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Cascading effects

Sea ice plays a vital role.

While it doesn't directly affect sea level rise, as it's already floating in the ocean, it does have indirect effects.

Its disappearance leaves coastal ice sheets and glaciers exposed to waves and warm ocean waters, making them more vulnerable to melting and breaking off.

A lack of sea ice could also have significant impacts on its wildlife, including krill on which many of the region's whales feed, and penguins and seals that rely on sea ice for feeding and resting.

More broadly, Antarctica's sea ice contributes to the regulation of the planet's temperature, meaning its disappearance could have cascading effects far beyond the continent.

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The sea ice reflects incoming solar energy back to space, when it melts, it exposes the darker ocean waters beneath which absorb the sun's energy.

Parts of Antarctica have been seeing alarming changes for a while.

The Antarctic Peninsula, a spindly chain of icy mountains which sticks off the west side of the continent, is one of the fastest warming places in the Southern Hemisphere.

Last year, scientists said West Antarctica's vast Thwaites Glacier – also known as the "Doomsday Glacier" – was "hanging on by its fingernails" as the planet warms.

Scientists have estimated global sea level rise could increase by around three metres if Thwaites collapsed completely, devastating coastal communities around the world.

Scambos said that this winter's record low level of sea ice is a very alarming signal.

"In 2016, [Antarctic sea ice] took the first big down-turn," he said.

"Since 2016, it's remained low, and now the bottom has fallen out.

"Something major in a huge part of the planet is suddenly behaving differently from what we saw for the past 45 years."

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The discovery of four dead women in a drainage ditch just outside Atlantic City in the US was shocking news in 2006.

International media flocked to the seaside gambling resort. More than 100 detectives and prosecutors were assigned to investigate. Casino guests worried about safety, and the victims' fellow sex workers began carrying hidden knives.

But as the years passed, the public's attention and fear faded, and the case of the "Eastbound Strangler" – so named for the direction the victims' heads were facing – remained unsolved.

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The arrest earlier this month of a man charged with killing three women whose remains were found on a Long Island beach in 2010 has breathed fresh life into another long-dormant case with obvious parallels; the Gilgo Beach serial killings involve a total of 11 victims, most of whom were young, female sex workers.

Yet the recent breakthrough, and the rekindling of public interest, only highlights a painful truth: Many similar cases – like the one in Atlantic City – remain open.

The FBI would not say how many killings of sex workers in the US remain unsolved.

Media accounts and statements from local authorities show a long trail of open cases, from nine women whose bodies were found along highways in Massachusetts, to 11 found dead in New Mexico, and eight more found amid the crawfish farms and swamps of southern Louisiana.

The killings of other sex workers in Chicago, New Haven, Connecticut and Ohio, among other places, also remain mysteries.

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From the days of London's Jack The Ripper in the 1880s, serial killers, particularly those preying on sex workers, have often gotten away with it, in part because their victims were easy targets living on the margins of society.

Gary Ridgway, the so-called Green River killer convicted of 49 killings in Washington state, said at during a 2003 court hearing in which he pleaded guilty that he chose sex workers as victims because he knew they would not be missed quickly, if at all.

"I picked prostitutes because I thought I could kill as many of them as I wanted without getting caught," he said.

Two women were out for an afternoon walk near Atlantic City in November 2006 when they found a body in a ditch. They called police, who quickly found three others nearby.

The cheap motel in Egg Harbor Township behind which the four bodies were found is long gone. It was torn down in an attempt to clear a seedy area known for crime, drugs and disturbances – and the murders of Barbara Breidor, 42, Molly Jean Dilts, 20, Kim Raffo, 35, and Tracy Ann Roberts, 23.

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Because it is near the ocean, like Gilgo Beach, the location has prompted much speculation by amateur detectives about a single killer, but some other online sleuths have pointed out that oceanside areas are often the remotest locations after hours on the densely packed East Coast. Gilgo Beach is about 3.5 hours drive from Atlantic City.

Gone in New Jersey are the four small wooden crosses someone erected on the site, along with the folded-up paper note bearing a Biblical quote promising justice that someone left there on one of the anniversaries of the discovery of the bodies.

For families left behind, each new day without word in the case of their loved one brings fresh pain.

"I kind of lost hope that anyone was even searching for the killer anymore," said Joyce Roberts, whose daughter Tracy Ann was one of the four Atlantic City-area victims.

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"The first six months, the prosecutor did get on the phone with me and told me they were working on it.

"Then it just fell off the radar. It was like nobody cared anymore."

That is a sentiment echoed by Phoenix Calida, a former sex worker from Chicago who now advocates for them through the Sex Workers Outreach Project.

"Police departments often refer to it as an 'NHI' case: No humans involved," she said.

"You feel like the only way you'll be remembered is when they catch the serial killer who killed you, and then they'll make five movies about him and no one will remember your name."

Massachusetts State Police are investigating "nine unsolved homicides possibly committed by the same person," said David Procopio, a spokesperson for the agency. He said two additional missing persons cases may be homicides related to the other nine.

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Gilbert Gallegos, a spokesman for the Albuquerque Police Department, said the New Mexico cases remain actively investigated, with "multiple detectives" working them. The 11 victims were all involved in drugs and prostitution, police said.

A reward of US$100,000 (about $150,000) has been offered for information leading to an arrest and conviction in the case, which involved two victims who were just 15 years old.

Despite the decade-long efforts of a local, state and federal task force, Louisiana has at least eight unsolved apparent homicide cases involving sex workers between the ages of 17 and 30. Their bodies were found in marshy areas in Jennings, a small town in the area known as Cajun Country, between 2005 and 2009.

Prosecutors in New York's Suffolk County investigating the Gilgo Beach cases have been in touch with multiple law enforcement agencies, but District Attorney Ray Tierney would not say which ones.

"Everything is being examined and looked at, and this is an active investigation," said Anthony Carter, Suffolk County's deputy police commissioner. He would not say if his agency was investigating any connection between Gilgo Beach suspect Rex Heuermann and the Atlantic City murders.

Atlantic County Prosecutor William Reynolds said the four cases from the drainage ditch outside Atlantic City remain active, with detectives assigned to them, but would not say how many. He declined comment on the Long Island case "as we are not involved."

Joyce Roberts, the victim's mother, said no one from law enforcement has called her since the arrest was made in the Long Island cases.

Police in Las Vegas, where Heuermann owns a time share, said they are investigating whether Heuermann may be involved in cases involving the killings of sex workers there.

In the months immediately after the bodies' discovery near Atlantic City, the local prosecutor's office and a dozen other law enforcement agencies had 140 people assigned to the cases, Ted Housel, who was prosecutor at the time, said in 2008. By the first anniversary, the total had fallen to 85, and those investigators were also working other cases.

Calida, the former sex worker from Chicago, said women involved the sex trade are frequently robbed by people who know they're carrying cash, and are sometimes coerced into sexual activity by police in return for not being arrested.

She said an attacker "knows you can't or won't report it. You're an easy target and they know it."

Three of her friends who were also sex workers in Chicago also turned up dead.

"You see someone, you become friends with them and then one day they're suddenly just not there," she said.

"We'd all go out asking around and looking for them, and then a few days later a body would be found. There's always this specific fear that it's a serial killer. Sometimes we never even get a body back to bury. And we wonder: Will law enforcement take it seriously because it's 'just another sex worker?'"

Melanotan gained popularity on social media for its ability to give users a tan without the sun – but experts are warning against the popular drug, now being bought on the black market.

Melanotan 2 was nicknamed "the Barbie drug" for its effect, but the Therapeutic Goods Association (TGA) is embarking on a crackdown on the dangerous peptide.

It's easily available, able to be bought from illegal sellers on platforms like TikTok and Instagram, alarming experts.

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Supplying and advertising banned substances like Melanotan 2 can lead to jail time and fines of more than $1 million, and the TGA is proving it's serious about attempting to stamp out access.

In the past 12 months the authority has ordered the removal of more than 500 unlawful advertisements from TikTok and Instagram and identified close to 300 illegal importations of the product.

Dermatologists say the safest bet is fake tan, but warn you still need to apply sun screen if you're heading outdoors.

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It was a violent night across Melbourne's northern suburbs with three men shot and another two injured in separate incidents.

Police say the attacks were targeted and are investigating whether they are connected.

Just after 9.30pm three men stormed a home in Meadow Heights.

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Police said the trio confronted one of the occupants, who was shot in the leg.

The 26-year-old was taken to the Northern Hospital in a stable condition.

The residents say they didn't know their attackers.

Neighbours have told 9News it's not the first time police have been called to the Amarina Close address.

Faiq Azim said he was "quite shocked".

"[There was] a lot of banging on the door, cussing, yesterday was the worst," Azim said.

The gunmen sped off in a Sedan.

Three hours later there was another shooting, nine kilometres away in Glenroy.

Local Moy Pati said he was "worried about this, especially with a young family".

When police arrived at the View Street home, two men in their 20s had been slashed, a 45-year-old man had been shot and a 43-year-old took himself to hospital, also with a gunshot wound.

Police are not sure how many were involved.

"We still don't know how those injuries occurred," Victoria Police said.

A large portion of the street was closed off to residents for most of the day as police searched for evidence.

Those injured are not co-operating with officers.

Police are investigating whether the two shootings are linked, especially because they are so close together.

Detectives stressed that both were targeted attacks and there was no threat to the wider community.

They're also probing whether there's any connection to organised crime gangs.

READ MORE: Man dies after alleged stabbing in Sydney harbourside suburb

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