InSight 3 months from checking Mars’ temperature

Jason Rhian

While former NASA astronaut Scott Parazynski might have scaled Mount Everest, there are mountains on Mars that far outstrip even Everest’s staggering 29,029-foot (8,848-meter) height. NASA has a spacecraft on its way to the Red Planet to try and find out why these peaks reach such heights.

The highest mountain on Mars, Olympus Mons, has a footprint roughly that of the state of Arizona and ascends an estimated three times the height Everest, Earth’s highest mountain, to some 72,000 feet (22,000 meters). While this shield volcano might be the Martian “king” of mountains, it isn’t alone in terms of impressive peaks.

In the same region as Olympus Mons, the Tharsis plateau, reside three other volcanoes. Not much is known about the processes that drove these massive peaks so high into the skies above the Red Planet. NASA has a mission on its way to Mars that could find out why: InSight.

The mission’s full name is “Interior Exploration using Seismic Investigations, Geodesy and Heat Transport,” but mission managers have abbreviated that to “InSight.” The lander is scheduled to touch down at Elysium Planitia at Mars on Nov. 26, 2018.

“Most of the planet’s geology is a result of heat,” said Sue Smrekar of JPL, InSight’s deputy principal investigator, in a NASA news release. “Volcanic eruptions in the ancient past were driven by the flow of this heat, pushing up and constructing the towering mountains Mars is famous for.”

It is hoped that reviewing the data provided by InSight will aid scientists in learning more about the processes that help form terrestrial, rocky worlds like Earth. The spacecraft is designed to be the first lander to delve beneath the surface of Mars to study the flash-frozen world’s deep interior. To accomplish this, the design deviates from the lander it was derived from—2008’s Mars Phoenix Lander.

However, rather than using a suite of instruments to study the geologic history of water, as was the case on Phoenix, the InSight lander has instruments that will be moved from the deck of the spacecraft to the surface to study the inner-workings of the planet. Those instruments include a seismometer and a heat flow probe. The latter is called the Heat Flow and Physical Properties Package (HP3).

HP3 is designed to provide measurements of the heat that emanates from the planet’s interior. The information gathered could provide a wealth of data, including the rate of decay of radioactive elements and other relics of the Red Planet’s formation some 4 billion years ago.

“We want to know what drove the early volcanism and climate change on Mars,” said HP3 investigation lead Tilman Spohn of the German Aerospace Center in a NASA news release. “How much heat did Mars start with? How much was left to drive its volcanism?”

InSight is an international affair, the German Aerospace Center (DLR) is also working on the project. This organization constructed and will operate HP3, which includes a probe called a “mole” that will pummel the ground, burying itself and dragging a tether behind it. Temperature sensors embedded in this tether will measure the natural internal heat of Mars.

According to NASA, the mole will have to burrow deep enough to avoid the wide temperature swings of the Martian surface. The space agency said even the spacecraft’s own “body heat” could affect HP3’s readings.

“If the mole gets stuck higher up than expected, we can still measure the temperature variation,” Spohn said. “Our data will have more noise, but we can subtract out daily and seasonal weather variations by comparing it with ground-temperature measurements.”

Additionally, as the mole works its way into the surface it will give off “heat pulses,” according to NASA, and warm the surrounding rock. Scientists can use that information to determine how well the heat is conducted by the rock gains at the landing site. The U.S. space agency said densely packed grains conduct heat better and is “an important piece of the equation” to understand the internal energy of the Red Planet.

Smrekar said planets are like engines and are driven by heat that moves their internal parts around. The scientist noted that HP3 will be “lifting the hood on Mars’ engine” for the first time.

“Most of the planet’s geology is a result of heat,” Smrekar said. “Volcanic eruptions in the ancient past were driven by the flow of this heat, pushing up and constructing the towering mountains Mars is famous for.”

Video courtesy of JPL