MarCO-B was flying by Mars with its twin, MarCO-A, to attempt to serve as communications relays for NASA's InSight spacecraft as it landed on Mars.
Mars' well-preserved interior provides a snapshot of what Earth may have looked like following its formation 4.5 billion years ago, according to Banerdt. Catch InSight extending the solar panels it uses for battery in the GIF below. In less time than it takes to hard-boil an egg, the lander had to slow itself from a speed of 12,300 miles per hour to just 5 miles per hour before gently touching down on the Mars surface.
A central question is why Mars, once a relatively warm, wet planet, evolved so differently from Earth into a mostly dry, desolate and cold world, devoid of life. The remains of a liquid core could suggest that Mars once had a magnetic field.
Studying Mars lets us travel to the solar system's ancient past.
After the historic InSight touchdown on Mars, NASA is now set to focus on Moon mission by announcing new partnerships with American companies, the U.S. space agency said.
Another instrument will burrow almost 16 feet into the soil to measure the heat coming from the interior of the planet, which, like Earth, is still cooling from its fiery creation 4.5 billion years ago.
The landing went largely as expected. This will help mission scientists determine where its will place instruments. Nearly as many missions to Mars have failed as have succeeded.
Apollo missions to the moon brought seismometers to the lunar surface as well.
Though it will be weeks before InSight returns its first measurements of the Martian depths, Monday's landing marks a scientific transformation, observes Marina Koren in The Atlantic: "Geology-the most earthly of all sciences-is about to become interplanetary".
The "Send Your Name to Mars" promotion was launched by NASA in 2015 as a way of generating more public interest in space exploration.
Meanwhile, a radio transmitter will send back signals tracking Mars' subtle rotational wobble to reveal the size of the planet's core and possibly whether it remains molten. And since InSight will be conducting experiments for a whole Martian year on the Red Planet (which is about two earth years), the probe has a scaled-up solar panel model compared to the one NASA used in the six-month long Phoenix Mars Landermission in 2008.