It is known it's hard to land on Mars, but NASA did just that with its recent landing gear, the InSight. Since childhood, I have loved to watch the landing and other maneuvers of the spacecraft on television – I always feel a little because of the strong excitement. But it did not prepare me to watch the mission I was working on. Each period of silence during the seven-minute descent Insight felt like an eternity, with time re-manifesting itself only during calls from system engineer Christina Salai. I will never forget the joy of the moment when she finally announced the confirmation of the "landing".
The InSight mission has more than 10 years of planning. Among planetary missions, this is a bit strange. While most missions are designed to observe the surface or atmosphere of planetary bodies, the purpose of InSight is deep observation of the surface – helping us to understand the secret of how it and other rocky planets formed.
The planting machine has a number of instruments, including seismometers, a heat flow sensor, a magnetometer and a radio transmitter. The probe of heat flow and physical properties (HP3) will be hammered to a depth of five meters below the surface of Mars, which is almost two times more than the portable teachings of the lunar missions. His measurements will tell us how quickly the heat from the inner side of the planet is lost – helping us to understand how Mars cools with time.
The rotation and internal structure experiment (RISE) will essentially be a rejection of the radio signal sent from Earth back to us. The difference in frequency between the source and return signals can then be used to determine the speed of the InSight landing gear relative to the Earth, rather, as the siren's height tells us whether it is moving towards us or away from us. We are particularly interested in using speed to tell us how the axis of rotation of Mars oscillates over time. The size of these fluctuations depends on the structure of the interior and especially on its dense metal core. Just as a raw egg drips more than a solid when it rotates on a flat surface, Mars will fluctuate more if its core is liquid.
I am working on a seismic experiment for the internal structure (SEIS), which consists of two seismometers installed on the alignment system, which will be located at a height of about 15 cm above the surface of Mars. This experiment is designed to tell us about the amount of seismic activity on Mars. We will also use the time required for seismic waves to reach seismometers to tell us about the temperature and the composition of the interior, rather, as a doctor uses a CT scanner.
We now have about three months, during which the tools will be deployed and activated. Over the next few days, the health of the systems will be checked, and the landing pad and surrounding area will be carefully displayed so that the task force can decide where to place the InSight probe and seismometers. The first image taken from the surface suggests that we landed on a shallow crater filled with sand almost free of stones, so it looks like there will be many options.
Around mid-December, the robotic arm will lift the seismometers installed on the tripod from the deck of the landing gear and lower them to the surface. After detailed checks, the leveling system will be used to ensure that the seismometers are perfectly horizontal. By mid-January, a shield should be installed at the top of the seismometers to protect against the elements. They can then be turned on, and the heat flow sensor will be deployed.
The heat flow sensor will begin to return data as soon as it starts to break through below the surface, so we expect to receive results in the first half of 2019. The radio experiment will take a little longer. It so happened that over the next year we will not be able to see the oscillations of the pole of Mars. This is a change in mid-2020, when we have to be perfectly positioned to uncover the secrets of its core.
As for the SEIS experiment, when we see that something exciting will depend on how often seismic energy is generated. Currently we do not know. We know that there are two potential sources of seismic activity: the impact of a meteorite and the “mesques” created by movement along faults near the surface.
Although we know that meteorites often attack Mars, the speed of faults is a mystery. Unlike the Earth, Mars has no moving tectonic plates, so it is believed that the movement of faults occurs when the inner part of the planet cools. However, some of the smallest errors on Mars appear to have been formed not by cooling, but by the movement of molten rock beneath the surface. Detecting the frequency and nature of the tags will help us understand the specific reasons.
Thanks to its three main experiments, InSight will provide a “snapshot” of the current state and composition of Mars. But scientific discoveries do not end here. Ultimately, the mission will help us understand the processes that occurred more than 4.5 billion years ago, when the solar system was very young.
That's why. The composition of the planet is established when it is formed, which in the case of Mars was only a few million years after the sun ignited. We think that as a result of its greater distance from the Sun, Mars was formed from a different, more volatile rich material than the Earth. However, until the composition of Mars is known, this idea is very difficult to test and develop. Data from InSight will provide a fundamental key to understanding how rocky planets formed in our solar system — and perhaps even surrounding other stars.
The composition, temperature and magnetic field of our planet are also vital to sustain life on our planet. Thus, despite the fact that InSight is not looking for life, it will give us new clues as to how the Earth was uniquely loaded onto life more than four billion years ago.
InSight already has a huge engineering success, and the scientific team now has an incredible opportunity to use it to reveal the secrets of Mars. We hope you are as excited as we are.
- Written by Bob Michill, Honorary Fellow, Space Agency UK, University of Bristol
- This article is reprinted from Creative Commons Talk