Planetary scientists are celebrating today, with the announcement from NASA that the InSight rover has successfully landed on the planet Mars.

The NASA spacecraft is designed to burrow beneath the surface of Mars, and relay back data on the inner structure of the red planet. Previous spacecraft that were sent to Mars were able to dig down a few inches and studied the surface rocks and dust, but this will be the first probe to go deep into the underlying rocks.

InSight has been traveling through space for six months, covering nearly 500 million kilometers and culminating in a six minute descent through the Martian atmosphere. There was some uncertainty in the landing site, but preliminary photos from the lander show a sandy surface with very few large rocks. This is exactly what scientists were hoping for, and should make the next stages of the mission easier than if the lander had ended up on a mountain top!

This was was NASA's ninth attempt to land at Mars since the success of the 1976 Viking probes, and the eighth successful mission.

The next stage will be for the 1.8 meter robotic arm to install a seismometer into the surface, which will allow scientists on Earth to monitor "Mars quakes". The second part of the mission will be to place a mechanical drilling unit onto the surface, which will actually hammer itself down through five meters of the Martian surface before settling into its final position. At that point the rover will begin transmitting data about the subsurface, including information on the temperature beneath the Martian plains.

By examining the properties of the Martian rocks, scientists are hoping to better understand how our solar system's rocky planets formed 4.5 billion years ago, and perhaps gain a better understanding of why different planets have vastly different properties - from cold, dry Mars to the heated, dense Venus or Mercury, to the habitable properties of our own Earth.

The one critical mission that InSight will not be conducting however is the search for Martian life. That mission is expected to be conducted by a new rover, still in the planning stages, that is set to reach the red planet in two years time and then, if successful, will return Martian rocks to Earth for a more detailed analysis.

But that is the future, and this is today. For today the world is celebrating another successful Mars landing, and another step forward in our fundamental understanding of our own Solar System.