In order to determine whether planets in our solar system have cores in their centers of existence, seismologists from The Australian National University (ANU) have developed a new technique to scan the deep interiors of planets.
The scanning technique, which uses sound waves to produce images of a patient’s body similar to an ultrasound scan, only needs one seismometer on a planet’s surface to function. Additionally, it can be used to verify the size of a planet’s core. The study has been published in Nature Astronomy.
With the ANU model, the researchers scanned the whole inside of Mars to confirm the massive core idea, which was first supported by a group of scientists in 2021.
According to study co-author Professor Hrvoje Tkali of the Australian National University (ANU), the Martian core, which is smaller than the Earth’s, has a diameter of around 3,620 kilometers.
In a way that has never been done before, “our research proposes a unique strategy employing a single piece of equipment to scan the innards of any planet,” he stated.
Scientists can gain more knowledge about a planet’s past and evolution by confirming the existence of a planetary core, which researchers refer to as the “engine room” of every planet. It can also aid researchers in figuring out when a planet’s magnetic field first developed and then vanished.
A planet’s magnetic field is actively maintained by its core. If this is the case with Mars, it may shed light on why, unlike Earth, the Red Planet no longer has a magnetic field, which is essential to the survival of all life.
The Martian core, which is predicted to be liquid and primarily composed of iron and nickel, may also contain traces of lighter elements like hydrogen and sulfur. Lead author Dr. Sheng Wang, who is also from the Australian National University, explained that these substances can change how well the core transports heat.
Life on Earth is possible because of the magnetic field, which protects humans from cosmic radiation.
The ANU team measured particular types of seismic waves on Mars using a single seismometer.
As the seismic waves from marsquakes bounce around the interior of Mars, they send out different signals, or “echoes,” that change over time.
The Martian core is penetrated by and reflected by these seismic waves.
Professor Tkali says that scientists are interested in “late” and “weaker” signals that can last for hours after being sent out by earthquakes, meteoroid impacts, and other events.
The resemblance between these weak signals acquired at various points on Mars shows itself as a new signal that reveals the presence of a huge core in the Red Planet’s heart, Professor Tkali said. “Although these late signals appear to be noisy and not useful,” he added.
We can calculate the distance that these seismic waves must travel to reach Mars’ core as well as how quickly they move through the planet’s interior. We can estimate the size of Mars’ core using this data.
According to the researchers, it is also a “cost-effective option” to confirm the existence of a planetary core using only one seismometer.
“On Mars, there is only one seismic station. In the 1970s, there were four of them on the moon. Due to the high cost, it is unlikely that the condition of having a small number of instruments will alter in the upcoming decades or even this century, according to Dr. Wang.
“Right now, we need a method to examine the planet’s innards using only one seismometer.”
The researchers hope that this new seismometer-only method, which was made by the Australian National University, will help scientists learn more about the moon and other planets in our solar system.
There is an opportunity for further research using new and more advanced sensors, according to Professor Tkali. “The US, China, and Australia want to send seismometers to the moon, and Australia also hopes to participate in future missions.”
Despite the fact that there has been research on planetary cores, our understanding of planetary innards remains hazy.The ability to obtain better images, however, will allow us to address issues like the size of the cores and whether or not they take a solid or liquid shape.
Our technology could be used to study even the moons of Jupiter and the solid planets in the outer parts of the solar system.
ANU researchers used the seismometer on NASA’s InSight lander, which has been collecting data about marsquakes, the weather on Mars, and the inside of the planet since it landed on Mars in 2018.
