Sunday , August 14 2022

After a nail-biting landing, here's what's next for Mars InSight


It's notoriously hard to land on Mars, but NASA managed it just for the recent InSight lander. From childhood, I've loved watching landings and other spacecraft manoeuvres on TV – always feeling a bit of that edge of the seat excitement. But it did not work for me. Each time of silence, during the seven-minute descent of InSight, it's time to re-exert its name. I will never forget the place of the moment when she finally announced "touchdown confirmed".

The InSight mission has been over ten years in the planning. Among the planetarious missions, it's a bit of an oddball. While the majority of missions are designed to look into the surface or atmosphere of planetarium, InSight's goal is to look deep underneath the surface – helping us crack the mystery of how and how the other rocky planets are formed.

The lander carries a number of instruments, including seismometers, a heat flow probe, magnetometer, and a radio transmitter. The Heat Flow and Physical Properties Probe (HP3) will be a total of five meters below Mars' surface, almost two times as far as the handheld drills of the lunar missions. Its measurements will tell us how cool heat is from the planet.

The Rotation and Interior Structure Experiment (RISE) will essentially bounce a radio signal from Earth back to us. The difference is that the difference between the frequency and the frequency of the signal can be adjusted. We're specially interested in using the velocity to tell us how Mars' axis of rotation wobbles over time. The size of these wobbles is that of the structure of the interior and especially its dense metallic core. Just like a raw egg wobbles when a spinning on a flat surface, Mars will wobble more if its core is liquid.

I work on the Seismic Experiment for Interior Structure (SEIS), which consists of two seismometers, about 15cm above the surface of Mars. This experiment is intended to tell us the amount of seismic activity on Mars. We use a physician who uses a CT scanner to describe the seismic waves.

The next few months

We have about three months during which the instruments will be deployed and activated. Over the next few days, the health of the systems will be checked, and the surrounding area will be thoroughly imaged. The first image taken from the surface suggests that we have landed on a shallow sand-filled crater almost free of rocks, so it looks like there will be multiple options.

The first image returned from InSight. The black specks are on the protective transparent lens cover, which was not removed yet.
Courtesy NASA / JPL-Caltech.

Around mid-December, a robotic arm will lift the tripod-mounted seismometers off the deck of the lander and lower them to the surface. After detailed checks, the seismometers are perfectly horizontal. By mid-January, a shield should be placed over the top of the seismometers to protect them from the elements. Then they can be turned on, and the heat flow probe will be deployed.

The heat flow probe will start returning data as soon as it begins to hammer its way down the surface. So, the radio experiment will take somewhat longer. It just so happens that, the next year, we will not be in the position to see the wobble of Mars' pole. That changes in mid-2020, when we should be ideally situated to uncover the secrets of its core.

As part of the SEIS experiment, when we see something exciting will depend on how often a seismic energy is generated. We do not currently know this. What we are knowing is that there are two potential sources of seismic activity: meteorite impacts and "marsquakes".

A 30 meter crater on Mars created by an impact sometime between 2010 and 2012.
NASA / JPL-Caltech / University of Arizona

While we know that meteorites frequently hit Mars, the rate of fault motion is a mystery. Unlike the Earth, Mars has no moving tectonic plates, so it is estimated that the fault movement happens as the planet's interior cools. However, some of the youngest faults on Mars appear to have been formed, but by the movement of the molten rock beneath the surface. Discovering the frequency and nature of marsquakes will help us work out the exact reasons.

Cerberus Fossae, a Martian fault under 10m years old.
ESA / DLR / FU Berlin

The big questions

Through its three main experiments, InSight will provide a "snapshot" of the current state and composition of Mars. But that is not where the scientific discoveries will end. Ultimately, the mission would help us figure out more than 4.5 billion years ago, when the solar system was very young.

Here's why. The composition of a planet was set when it was created, which was only a few million years after the sun was ignited. We think that as a result of its great distance from the sun, Mars has been formed from different, more volatile-rich material than Earth. However, until Mars's composition is known, this idea is very hard to test and develop. The data returned from InSight will be a fundamental key to understanding how the rocky planets are in our solar system formed – and maybe even those around other stars.

The composition, temperature and magnetic field of our planet are also vital to sustaining life on our planet. So even though InSight is not looking for life, it was a great way to get it back.

InSight has already been a huge engineering success, and the science team is now getting the incredible opportunity to reveal Mars' secrets. We hope you're excited as we are.

Source link