The mission will study the Red Planet's deep interior
NASA has launched its latest mission to Mars.
The mission will study the deep interior of the Red Planet to learn more about how rocky planets like Earth and Mars are formed.
The InSight lander is carrying equipment that can detect Marsquakes and measure the flow of heat from the centre of the planet.
After travelling some 484 million kilometres, the space-craft is expected to reach Mars in late November.
“I’ve been to several rocket launches, but it is a whole different vibe when there is something you've been working on for years sitting in the nose cone waiting to get hurled beyond our atmosphere,” said Bruce Banerdt, the mission’s principal investigator at Nasa’s Jet Propulsion Laboratory.
“But as exciting as launch day will be, it’s just a first step in a journey that should tell us not only why Mars formed the way it did, but how planets take shape in general."
The mission is described as Mars’ "first thorough check-up since it was formed 4.5 billion years ago."
The lander is launching on board a United Launch Alliance (ULA) Atlas V rocket. It is the first US interplanetary space-craft to launch over the Pacific Ocean.
NASA said it will reach orbit around 13 minutes after launch, when the rocket is around 1,900km northwest of Isabella Island, Ecuador.
The space-craft is due to land on a broad, smooth plain close to the planet's equator called the Elysium Planitia.
The landing site is around 600km away from where the Curiosity rover made its landing.
The InSight lander is expected to spend two years studying the Red Planet’s interior.
The French-built seismometer it is carrying is designed to detect the slightest vibrations from "marsquakes" around the planet.
Scientists expect to see up to 100 ‘marsquakes’ over the course of the mission.
It is also fitted with a German-made drill that can bore as far as 5 metres underground, measuring interior heat.
The rocket is also carrying a pair of miniature satellites called CubeSats, which will fly to Mars behind the lander.
Unlike Earth, where quakes are caused by tectonic plates, Mars has very quiet tectonic processes.
This means marsquakes are more likely to be caused by other forms of tectonic activity, including volcanism and cracks forming in the planet's crust.
NASA said: "Each marsquake would be like a flashbulb that illuminates the structure of the planet's interior.
"By studying how seismic waves pass through the different layers of the planet (the crust, mantle and core), scientists can deduce the depths of these layers and what they're made of.
"In this way, seismology is like taking an X-ray of the interior of Mars."
Earth and Venus have tectonic systems which have destroyed most evidence of their early history, but Mars (which is just one third the size of those planets), contains less energy to power these tectonic processes.
NASA said this makes Mars a fossil planet in many ways because it has remained static for more than three billion years.
The mission is launching from Vandenberg Air Force Base in California.
Usually, missions to other planets launch from the Kennedy Space Centre in Florida and fly east, over the water of the Atlantic Ocean.
Flying towards the east adds the momentum of Earth's eastward rotation to the launch vehicle's own thrust - but the Atlas V-401 rocket is powerful enough to fly south towards the sea from Vandenberg.