The US Coast Guard has confirmed that a Canadian P-3 aircraft detected "underwater noises" in a search area for the missing Titanic sub
US media, citing internal US government memos, described them as "banging sounds"
It is unclear when and how long the banging lasted, according to Rolling Stone and CNN
Contact with the miniature sub which has five people on board was lost on Sunday as it made a 3,800m descent to the Titanic wreck off the coast of Newfoundland, Canada
Search authorities estimate the vessel has less than 30 hours of oxygen left
British-Pakistani businessman Shahzada Dawood and his son Suleman are on board, along with British billionaire explorer Hamish Harding
Paul-Henry Nargeolet, a former French Navy diver who has explored the Titanic before, is also on the vessel, as is Stockton Rush, chief executive of OceanGate - the firm behind the dive
The search for the Titan sub is in a remote area of the Atlantic, making it a difficult rescue operation.
The wreck of the Titanic is about 600km (370 miles) off the coast of Newfoundland surrounded by a huge field of debris.
Image source, .
Image source, .We've just learned that Pakistani businessman Shahzada Dawood and his son Suleman, who are on board the sub, are British citizens.
That's according to a spokesman for the Dawood family in Pakistan who provided a statement to the BBC.
The family is one of Pakistan's richest. Dawood is a trustee at the SETI Institute - a organisation researching the origins and prevalence of life and intelligence in the universe.
He is also on an advisory board for the Prince's Trust international and has links to the British Asian Trust, organisations set up by the King as Prince of Wales, according to his profile on the SETI website.
We've heard some more from former submarine officer Frank Owen who says the first stage of the search operation would involve trying to communicate with the sub via transmitters.
It will be massively difficult to find the sub due to its size and it being in the middle of a debris field, the former director of the Australian Submarine Escape and Rescue project says.
Owen says when the Titanic sank, parts of the ship sank with it, but not all in the same place.
"It’s like searching for a mine in a minefield," he told the BBC, adding that it would be hard to know what is a rock and what isn't.
Referencing how the deep the Titanic wreckage is, Owen warns it is "well beyond" the depth capacities of many rescue systems.
As the search continues, we're going to be focussing on the questions you would like answered.
We'll put your queries to an expert on areas such as the Titan sub, how a rescue mission works and what we can expect to happen.
So please do get in touch with any questions you have and we'll start bringing you the answers in the next few hours.
You can also get in touch in the following ways:
In some cases a selection of your comments and questions will be published, displaying your name and location as you provide it unless you state otherwise. Your contact details will never be published.
Image source, .What is it like visiting the Titanic on a sub?
Mike Reiss, who travelled to see the Titanic on a submersible that has now gone missing, says it is "remarkable" how basic and simple the whole operation is.
We were all aware of the dangers going into it, he says, adding he had to sign a waiver beforehand that mentioned death three different times on the first page.
Frank Owen, former director of the Australian submarine escape and rescue project has been speaking to our colleagues at Radio 5 Live.
He says the submersible won't have distress beacons they can release to the surface, but instead will have to reach the surface itself before it can alert rescuers.
"There will be radio transmitters, GPS signals," he says. "There'll be strobe lights and radar reflectors to help the searching forces find them."
But all these distress signals can't be sent until the craft has reached the surface.
Owen says the submersible will have "several hundred kilos of metal" that can be ditched to give it enough buoyancy.
"That doesn't require power to do," he adds. "You can have a hydraulic hand pump to cut the cable and you would have expected that to have occurred."
The vessel that is missing with five people onboard is part of OceanGate Expeditions which charges guests $250,000 (£195,270) for a place on its eight-day expedition to see the Titanic.
The site of the famous wreck is about 600km (370 miles) off the coast of Newfoundland, and lies in two parts, with the bow and the stern separated by about 800m (2,600ft). A huge debris field surrounds the broken vessel.
A full dive to the wreck, including the descent and ascent, reportedly takes eight hours.
Each expedition lasts eight days, according to OceanGate, and each dive is meant to include a scientific objective, including studying the wreck's decay.
The inaugural dive took place in 2021, according to the company's website.
You can read our full story here.
Patrick Woodhead is the founder of White Desert Antarctica - which organises expeditions to the frozen continent - and he knows Hamish Harding well.
He says he is praying that the British businessman and explorer, and the rest of the passengers in the submersible, are found safe and sound.
Calling Hamish an "incredible aviation explorer in his own right" and a "true friend" of his company, Woodhead says Hamish has "travelled with us to Antarctica a number of times, including with astronaut Buzz Aldrin when he visited".
"Hamish is a great advocate for exploring the globe and discovering new pathways to help make the world a better place. Our thoughts are with his wife Linda and his sons at this anxious time, and may Hamish and the crew be located quickly," he says in a statement.
Image source, ReutersUS and Canadian teams are racing against the clock to find and rescue the small sub that went missing on Sunday.
The US Coast Guard's Rear Admiral John Mauger said on Monday that it is a challenge to conduct a search in such a remote area.
The search has two aspects, either on the ocean's surface or an underwater sonar search, he said.
The Coast Guard has sent two C-130 Hercules aircraft to search for the submersible on the surface of the water, and has been joined by a Canadian C-130, and a P8 aircraft equipped with underwater sonar capability. Sonar buoys are also being deployed in the area.
Rear Adm Mauger said it would need additional expertise to rescue the vessel if it was found underwater and he has reached out for help.
You can read more here.
We've just heard from Simon Platts who directed a BBC documentary episode about the Titan sub last year.
He says that Stockton Rush, the CEO and founder of the company that organised the mission, makes it clear that there is no guarantee that people on the dives will see the Titanic and that it is a "dangerous environment".
The director of the BBC's Travel Show says the technology used to control the sub is "innovative" and can occasionally go wrong.
Speaking to BBC Radio 4's Today programme, Platts said: "I got the impression that occasionally things go slightly wrong, but when I was there, there never seemed to be an indication that things could go catastrophically wrong."
The wreck of the Titanic is located about 600km (370 miles) off the coast of Newfoundland, Canada, and it sits 3,800m (12,500ft) deep at the bottom of the Atlantic.
The passenger liner hit an iceberg on its maiden voyage from Southampton to New York in 1912. Of the 2,200 passengers and crew onboard, more than 1,500 died.
The remains of the Titanic were discovered in 1985, and the site of the wreck has been extensively explored since then.
It lies in two parts, with the bow and the stern separated by about 800m (2,600ft). A huge debris field surrounds the broken vessel.
Image source, .Pakistani businessman Shahzada Dawood and British explorer Hamish Harding are among those on board
Image source, Getty ImagesThe Titanic hit an iceberg on 14 April 1912, during her maiden voyage from Southampton, England, to New York City in the US.
More than 1,500 of the 2,200 passengers drowned that day, in the deadliest sinking of a single ship up to that time.
US and UK inquiries into the sinking found, among other things, that the ship's lifeboats were not filled to capacity and cut backs to Titanic's design may have made things worse.
The actions of both survivors and those who perished have entered into folklore, with the event providing the basis for the disaster film genre and inspiring many artistic and cultural works, most notably the James Cameron blockbuster released in 1997.
Mike Reiss is a New York-based writer and producer, who has worked on the Simpsons, and took a trip on the Titan sub last year.
He told BBC Breakfast: "You sign a massive waiver that lists one way after another that you could die on the trip. They mention death three times on page one so it's never far from your mind."
"As I was getting onto the sub my thought was this could be the end.
"So nobody who's in this situation was caught off guard. You all know what you are getting into.
Quote MessageIt is really exploration. It is not a vacation. It's not thrill seeking, it's not sky diving. These are explorers and travellers who want to see something."
Image source, .One of those on the sub is Shahzada Dawood, along with his son Suleman. Dawood belongs to one of Pakistan's richest families. He is a trustee at the SETI Institute.
We've just been hearing from ocean researcher Robert Blasiak who says if the sub has dropped to the bottom of the ocean conditions will be tough.
He says the atmosphere pressures will be about 380 times more than would normally be felt on the surface walking around.
To put this in perspective, it is about 200 times the pressure in a car tyre, he says.
Speaking to BBC Radio 4's Today programme, Blasiak said that is why the sub has such thick steel walls.
We've just heard from Frank Owen, a former submarine officer, who says the challenge for the people onboard the sub will be maintaining composure and not consuming too much oxygen.
There is enough oxygen for 96 hours, but if "they start panicking or moving around too much they could exceed those rates", he told the BBC.
The former director of the Australian Submarine Escape and Rescue project said the second challenge was finding the sub.
It will be easier to find on the surface of the water, but can be difficult if it is trapped or entangled.
In 2022, the BBC filmed inside the Titan submersible that has gone missing.
This video features Stockton Rush, the chief executive of OceanGate - who is widely reported to be one of five people on the vessel. He takes us on a tour inside and shows us how the sub is controlled by a video game controller.
Watch: Inside Titanic sub before it went missing
CBS journalist David Pogue was invited to travel on OceanGate's Titan submersible on a press trip last year, to reach the wreckage of the Titanic.
He told the BBC that passengers were sealed inside the main capsule by several bolts that were applied from the outside and had to be removed by an external crew.
He said he initially thought the sub seemed improvised: "You steer this sub with an Xbox game controller, some of the ballast is abandoned construction pipes."
If the sub became trapped or sprung a leak "there's no backup, there's no escape pod", he said.
Image source, CBS NewsThe missing craft is believed to be OceanGate's Titan submersible (pictured)