With about 10 minutes, and 1,600km to go, the the ship has just jettisoned its cruise stage and attached fuel tanks.

It is now about to shed its ballasts, preparing it to make its entry into the Martian atmosphere.

Perseverance is the biggest, heaviest, most complicated rover Nasa has ever built.

It carries a suite of instruments to seek for signs of ancient life and collect rocks and soil for possible return to Earth.

Read more about the technology here.

We're now less than 30 minutes from the dreaded "seven minutes of terror" where Perseverance will touchdown on the Martian surface.

Watch as scientists begin exploring Mars for proof of the existence of ancient life.

Dr Sarah Milkovich, Planetary Geologist and Science Systems Engineer for Nasa's Mars mission, is wearing a tartan that she says is in honour of today's landing.

You're probably more familiar with the tartan as a chequered pattern garment that originates in the Scottish Highlands.

Presumably the red pattern is in honour of the Red Planet.

In case you're wondering, she's American, external - not Scottish.

A meme has just been spotted in the Nasa control room in California.

Dr Sarah Hörst, who teaches Earth and Planetary Sciences at Johns Hopkins University in Maryland, noticed that the "this is fine" dog was seen at the desk of the Entry, Descent and Landing director.

If you're not familiar with the meme, it features a dog sipping coffee in a burning room declaring "this is fine".

In the next hour, Perseverance will go from 20,000km/h - faster than the speed of sound - to stable on the surface of Mars.

The supersonic parachute is made of polyester, nylon and kevlar - the same material used in bulletproof vests.

Watch how the massive parachute was tested.

We're just about an hour out from the "seven minutes of terror," in which Perseverance will - if all goes according to plan - land on the Martian surface.

Because it takes about 11 minutes for a radio signal to get from Earth to Mars, the lander will be doing everything on its own with no human at the controls.

Image source, EPA

With under two hours to go until landing, let's take a look at Nasa's Mission Support Area at the Jet Propulsion Laboratory in Pasadena, California.

The top image shows Perseverance flight director Magdy Bareh moving the final marble out of the Earth jar and into the Mars jar.

Scientists have moved one marble for each day of the rover's 204-day flight to Mars.

Image source, EPA

Image source, EPA

Image source, EPA

Image source, NASA

Don't expect to see jubilant scenes of hugging scientists if all goes well with today's mission.

That's because Covid protection measures mean that those present in today's control room are only the most essential Nasa workers, and not the thousands that have participated in the Mars mission.

Nasa administrator Jim Bridenstine says that throughout the mission, Covid-19 measures were in place to make sure people felt safe working on the project.

"Our highest priority was the safety of our people and we wanted them to know if they come to work, they'll be safer at work than they would be at home," he says.

Using personal protective equipment, social distancing and scheduling changes to minimise how many people were working on the vehicle at one time, were all precautions introduced by Nasa due to the pandemic.

"This is all about perseverance," Bridenstine says. "Going to Mars is all about persevering in general. Doing it now is more persevering than before."

The rover has a Covid-19 "perseverance" plate affixed to it as well, with a logo featuring the symbol of medicine.

The name Perseverance came from Alexander Mather, a 13-year-old student from Virginia who won Nasa's essay contest to name the rover.

"We are a species of explorers, and we will meet many setbacks on the way to Mars," wrote Alexander - who hopes to work at Nasa one day.

"However, we can persevere. We, not as a nation but as humans, will not give up."

The name of the onboard helicopter, Ingenuity, was chosen by Vanessa Rupani, a high school student from Alabama.

"I'm over the moon, that was probably the coolest, most exciting thing I've seen ever," she said when Perseverance and Ingenuity left Earth last summer.

The Perseverance Mars Rover has a Twitter account, but no, it did not bring a smartphone into space.

"It's go time," the account just tweeted, sharing a link to Nasa's event live stream.

Earlier today, it tweeted that "the most dangerous part comes last: the final seven minutes."

"Once I get this part behind me, I’ll finally be able to get to work. Can’t wait."

Many aspects of this landing are similar to those used for the Curiosity rover's touchdown at Mars' Gale Crater in 2012.

But Perseverance will have a new capability called Terrain Relative Navigation. This allows the rover to avoid hazards such as sand traps, jagged rocks and small craters.

The rover has a pre-programmed map of potential hazards in its onboard computer. As it approaches its landing site in Jezero Crater, it captures images and compares them against the hazard map it already has.

"It will choose to divert away from hazards if it looks like it's heading towards one of the hazards we've identified," said Dr Katie Stack Morgan, deputy project scientist on the Perseverance mission.

Terrain Relative Navigation is also set to be used on Nasa's mission to return astronauts to the lunar surface this decade, which is known as Artemis-3.

Paul Rincon
Science editor, BBC News website

Image source, Nasa

Perseverance is carrying an experiment called Moxie, that will help prepare for the human exploration of Mars.

The Mars Oxygen In-Situ Resource Utilization Experiment will demonstrate a way that future explorers can produce oxygen from the Martian atmosphere for rocket propellant and for breathing.

Recently, I asked former Nasa astronaut Scott Kelly about the current feasibility of a human mission to Mars.

Kelly - who has a twin brother, Mark, who was also an astronaut - said that radiation is one of the biggest challenges.

"You'll either have to find a way to shield against the radiation or just get to Mars quicker so you're not exposed for a long period of time," he told me.

Scott Kelly spent a year in space between 2015 and 2016, in part to study how his body and health changed during a sustained period in microgravity. In part, it was designed to understand the kinds of challenges astronauts might face on a Mars journey, which could take longer than two years.

He said it wasn't "a showstopper", but that astronauts would experience 10 times the radiation on the Mars trip as Kelly was exposed to during his year on the International Space Station. The Earth-orbiting outpost is somewhat protected from cosmic rays and particles by the Earth's magnetic field.

"It would put the crew members at a not-insignificant risk of developing a fatal cancer at some point during their lives. But things have a risk and you have to weigh the risk and the reward. I'm pretty sure we'll figure out how to do this one day," he explained.

Mars is the only planet that is bright enough to be easily observable this month, according to website EarthSky.org.

It will be visible during evening and night hours in North America, and should be visible in the UK as well.

So maybe go take a peek for yourself, and imagine what is taking place 470m-km away.

Among the many firsts planned for today, Nasa will be hosting a Spanish-language broadcast of the Mars landing.

"Juntos perseveramos," - which means "together we persevere" - will be the agency's first ever Spanish broadcast for a planetary landing.

The programme will be hosted by Perseverance engineer Diana Trujillo and will feature Spanish-speaking Nasa employees that have worked on the Mars programme.

"The name of the show recognises that perseverance and diversity are critical to Nasa’s successful undertaking of ambitious missions," said acting Nasa chief of staff Bhayva Lal.

Image source, EPA

Dr Lori Glaze, Planetary Science Division Director at Nasa, is in charge of all interplanetary missions and is in charge of today's Mars landing.

"This is going to be the most precise landing we've ever executed," she tells the BBC's Christian Frasier, pointing out that it's the ninth US landing and fifth rover to be placed on Mars.

"All of our prior missions have had much larger landing areas they were trying to hit. But this particular location that we're going [to] has a lot of hazards so we really tried to narrow that down."

A "range trigger," which is tracking how far Perseverance has traveled since leaving Earth and its proximity to Mars, will help determine when to deploy the massive parachute that will be used to slow the spacecraft's descent.

"Terrain-relative navigation" is also being used to allow the Rover to scan the surface and compare what its seeing to existing maps of the region, she says.

And all of that will take place in around seven minutes, and without any human being manning the controls.

"My goodness, that seven minutes of terror is absolutely - its nail-biting you're so anxious just watching all the data come in," says Dr Glaze.

She says that she expects that she will feel the same way that she did during 2018's InSight Mars landing, which also featured a "seven minutes of terror".

"You can't even imagine how anxious you are."

Nasa scientists anxiously refer to the time in which the rover will enter Mars' atmosphere, go through it, and ultimately land on the surface "the seven minutes of terror".

Here's a look at some of the other eye-watering numbers:

20,000km/h - Perseverance is currently traveling at over 12,500mph - fast enough to get from London to New York in 15 minutes and six times faster than a speeding bullet.

470-million-km - The long journey to Mars was accomplished in about seven months, after launching from Florida in July 2020.

1025 kg - Perseverance is the heaviest rover ever deployed on Mars, and measures about three metres long.

Three missions- There are currently three mission to Mars being conducted. China and the UAE are joining for their first time; previously only the European Space Agency and the former Soviet Union have conducted Martian missions.

Image source, NASA

In anticipation of today's mission, the Empire State Building in Manhattan was lit up in Martian red last night.

Image source, Getty Images

Scientists at Nasa's Jet Propulsion Laboratory in Pasadena, California, have two jars set up in their Mission Support Area conference room.

One has a sticker with Mars on it, and the other a sticker showing Earth.

Each day that Perseverance is in flight, they have moved one red marble from the Earth jar to the Mars jar.

On Wednesday, with one day to go until touchdown, there was just one red marble left in the Earth jar.

The marbles used could be a reference to the 1972 photograph produced by the US Apollo 17 mission, which showed the entirely of Earth in a single frame.