Page 18 - EngineerIT July 2022

SPACE SCIENCES

InSight and the nearby Curiosity rover, patterns. It can also lead to a better understanding of space weather.
and add on-the-ground magnetism “These are also system-wide questions that are about understanding the planet as a
measurements that complement whole,” Johnson said. “Magnetic fields are cool because they connect the deep interior of
orbital observations from satellites the planet not just to the atmosphere but to the space around it.”
like MAVEN (Mars Atmosphere and Volatile It was especially helpful to have simultaneous observations from InSight on the
Evolution) and the Mars Global Surveyor. surface and MAVEN in orbit, Lillis said.
“We knew quite a bit about the
magnetic field environment of the planet, A bittersweet ending
but all of those observations came from Johnson said she had mixed feelings on seeing the mission coming to an end.
above the atmosphere,” Johnson said. “We’ve met and exceeded our primary mission goals and learned more than we had
“This was our first chance to get a look at planned,” she said. “But the sad part is that all of the instruments have been working
it on the surface of the planet.” really well. It’s not like the instruments are deteriorating or we’re not getting good data
Magnetism researchers focused on anymore.” The mission will end because its dust-crusted solar panels will no longer be
two key groups of scientific questions. able to power the lander.
One group focused on crustal magnetism. The timing is especially unfortunate because the Sun is now heading into solar
Although Mars now lacks a planetary maximum, a multi-year period of increased solar activity that would have led to
magnetic field, these rocks indicate that interesting magnetism observations, she added.
such a field once existed. Although InSight may be shutting down, it’s not the end of studying magnetism from
“Learning about these rocks is actually the surface of Mars. Johnson and Lillis noted that the Chinese rover Zhurong is equipped
very important because it can help us with a magnetometer, and they said they hoped its observations would be made public
better constrain the timing and strength soon. They also said InSight had laid the groundwork and served as a proof of concept for
of this ancient magnetic field on Mars,” future NASA missions to study Mars’s magnetic fields in greater detail.
Johnson said. “All this is tied to the “This just gave us a little taste,” Lillis said, “but it’s a very tantalising taste.” n
overarching goal of InSight, which is to
understand the interior structure and About the author
evolution of the planet.” Ilima Loomis has written for publications including Eos, Astronomy, Science, Nature,
Previously, Mars orbiters had Popular Science and Discover, and is the author of books including Eclipse Chaser:
observed that the planet’s crustal Science in the Moon’s Shadow.
magnetic fields were much stronger than
Earth’s, Lillis noted. Scientists wanted
to know if this was entirely due to the
magnetisation in the rocks themselves or
if other factors contributed.
Magnetic fields are cool because they
connect the deep interior of the planet,
not just to the atmosphere but to the
space around it.
In fact, InSight found that the rocks
were even more strongly magnetised than
previously thought. “We thought maybe
the fields…might be 100 nanotesla,” he
said. “Turns out they were about 2,000
nanotesla—20 times stronger than any
model had predicted.”
The second group of magnetism
questions focused on how the magnetic
field at the landing site would change
over time, Johnson said. A number of
factors contribute to fluctuations in
magnetic fields, including space weather,
the planet’s day-night cycle, and electrical
currents generated in Mars’s weak
atmosphere.
Understanding these fluctuations
can provide insights to help explain
the planet’s climate and atmospheric Dust crusted solar panel (Pic taken 22 April 2022 credit NASA/JPL-Caltech)

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