Six years after NASA's Curiosity rover landed on Mars in what has gone down in history as the seven minutes of terror, scientists have landed a new spacecraft on the Red Planet.

Key points: Mars InSight's landing went without a hitch

Mars InSight's landing went without a hitch Spacecraft is about the size of a dinner table, with "steampunk claw" attached

Spacecraft is about the size of a dinner table, with "steampunk claw" attached Its mission is to study Marsquakes

The Mars InSight lander, which blasted off in May, touched down early on Tuesday morning AEDT.

Its landing was not quite as nail-biting as Curiosity's, but it still carried an element of risk, said the mission's deputy lead, Sue Smrekar, of NASA's Jet Propulsion Laboratory.

"When it works, it looks smooth and easy — like a piece of cake — but in fact at least a third of missions that have been sent to Mars have failed," Dr Smrekar said.

In 2016, the European Schiaparelli lander, the only spacecraft to attempt to land on the planet since Curiosity, crashed and burned.

With the landing complete, Mars InSight will now embark on a mission to study the Red Planet's inner secrets.

"We've had many missions that have looked at the surface of Mars, but we're the first one that is really going to tell us about the interior of Mars," Dr Smrekar said.

The craft: A dinner table with a steampunk claw

The InSight lander — short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport — is very different to the Mars rovers.

"We do not have wheels — we actually need to stay in one place and be as quiet as possible," Dr Smrekar said.

About the size of a dinner table with two solar panels attached, the InSight lander is designed to take Mars's pulse and temperature.

The Mars InSight lander is the size of a dinner table with two solar panels attached. ( Supplied: NASA )

The craft is kitted out with a 1.8-metre robotic arm or "steampunk claw" that can delicately place two experiments — a 20-centimetre, dome-shaped seismometer, and a heat probe — into position.

"This is super-important stuff for us," Dr Smrekar said.

Viking 2, a previous mission to Mars did have a seismometer, but it stayed on the deck of the spacecraft.

"Basically it detected gusts of wind that made the lander shake, but you can't really detect seismic waves using that configuration [on the spacecraft]," Dr Smrekar said.

"So, for the first time we've got a seismometer and actually placed it on the ground."

The mission: Marsquakes and rocky cores

The seismometer will measure Marsquakes — subtle vibrations caused by internal rumblings, meteorites smashing into the planet or dust storms whipping across the surface, explains Katarina Miljkovic, an Australian-based scientist on the project.

"The seismometer will sit there and listen to any shakes and quakes that are coming off the interior," said Dr Miljovovic, from Curtin University.

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Observing the seismic waves bouncing around Mars will give the scientists an idea of what the internal structure of the planet looks like. This, in turn, can help us understand how rocky planets formed.

The heat probe, which can burrow 5m into the ground, could also give us more clues about the potential habitability of Mars, Dr Smrekar said.

"Understanding where water can be found is certainly a function of the temperature underground, so that will certainly help us in constraining what environments might be useful for finding either ice or possibly even liquid water," she said.

The craft will also have a radio antenna that can measure the planet's wobble.

The destination: The most boring place on Mars…

InSight landed at the Elysium Planitia, just 600km away from Curiosity.

But don't be fooled by the exotic name. This place is "the flattest, safest, most boring landing site ever on Mars," Dr Smrekar said.

Insight landed 600km away from the Curiosity rover. ( Supplied: NASA/JPL )

The volcanic plain is located near the equator, which guarantees the craft will have enough solar energy.

It is low enough to have enough atmosphere to slow the craft down on entry.

And finally, there aren't many rocks.

"We don't want our spacecraft to land on rocks — and when we put our heat flow probe down to burrow underground, we also don't want to have rocks in the subsurface," Dr Smrekar explained.

The landing: 6.5 minutes in the dark

Once InSight hit Mars's atmosphere, it took just 6.5 minutes to land.

The first signals came back approximately eight minutes later — the time it takes for a signal to travel at the speed of light from Mars to Earth.

"We can't command anything while this is happening. We have to just rely on getting the sequence of commands correct in advance," Dr Smrekar said.

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From the time it hit Mars's atmosphere — travelling at a speed of around 19,800 km per hour — InSight went through a series of steps.

Drag on the heat shield slowed the craft down, then it released a parachute and floated down towards the surface.

Close to the surface, it ditched the parachute and heat shield and fired up rockets.

"By the time we're almost to the ground, it's quite a gentle touchdown," Dr Smrekar said.

During the landing two mini satellites known as the Mars Cube One or MarCO satellites were riding shotgun, relaying signals at each phase back to ground stations on Earth.

They also sent the first fuzzy image taken by the InSight lander back to the Deep Space Network.

The team will spend the next couple of months choosing where to place the instruments, which will stay in place for at least two Earth years (one Mars year).

They'll take photos of the landscape to get information about slopes and rock height and take temperature data.

"We want to put our instruments down in the optimal place," Dr Smrekar said.

This will take time as the data is sent up via another spacecraft orbiting Mars, called the Mars Reconnaissance Orbiter.

"Then we'll start acquiring data for the rest of the Mars year," Dr Smrekar said.

Hear an extended interview with Dr Sue Smrekar on the Science Show.