May 12, 2021 – A three-year program at New Mexico State University, funded by the National Science Foundation and NASA, will see assistant professor of astronomy Wladimir Lyra create a roadmap for the formation of planets using supercomputers.
âThis survey will use powerful computers to produce simulations of the formation of the planets and compare the results with modern observations,â Lyra said. “This research will be able to decide which models are most likely to account for the formation of the planets.”
Lyra explained that the project will be the largest planetary theory training collaboration in the United States. NMSU works with the University of Arizona; the University of Nevada, Las Vegas; Iowa State University and SETI (Search for Extraterrestrial Intelligence) Institute.
âThe Earth is basically a ball of dust,â Lyra said. âWe want to know how the planets form around the sun. One of the clues is that even though space is three-dimensional, the solar system is mostly pancake-flat: all planets orbit the same plane. The easiest way to achieve this setup is if the planets form from a disk around the Sun. And the fact that Jupiter and Saturn are mostly made of gas implies that this disk was a disk of gas. If we are to understand the formation of planets, we need to understand the behavior of these gas disks around young stars.
There have been two main developments to allow a better understanding of the formation of planets: First, computers have become powerful enough to model these systems; second, telescopes are now powerful enough that astronomers can witness the formation of planets around young stars. These observations help researchers confirm their computer models.
Sounds easy? It’s not. There is a problem that classical physics has not solved.
âA ubiquitous process in gas is turbulence. Yet turbulence is the last unsolved problem in classical physics, âhe said. âWe cannot predict exactly how the turbulence will act in the future. This is because turbulent systems are chaotic, which means that the system is very sensitive to initial conditions. This led to the oft-mentioned idea that a butterfly flapping its wings can cause a hurricane.
It is this unpredictable movement of the way gas and dust form planets that Lyra and her collaborators are trying to create a model for using supercomputers.
âWhen the sun is shining in your room, you can sometimes see the particles in the air and the movement is random and turbulent,â Lyra explained. âThe same thing happens in space. We quantify for this by calculation. Dust is where the formation of planets comes into play. Like the dust in your room, the disks around young stars also contain dust. The dust collects in the dust bunnies first and then keeps growing more and more until you have pebbles and rocks made from these dust bunnies.The problem is you have to find a way to collect these pebbles and rocks and form them into a planet.
âIt won’t happen on its own, because the pebbles are too small to attract other pebbles. They don’t have enough mass to attract each other, but turbulence allows them to come together, collapse, and form a planet.
Over the past 10 years, field researchers have observed movement in the disks forming around young stars that resemble forces like the hurricanes we see on Earth.
âThese vortices are very good at concentrating dust,â he said. âRight now, we’re running a model on the computer that shows that the concentration of pebbles in one of these hurricanes is able to reach the density necessary to reduce them to planets.â
Lyra’s research is focused on finding ways to generate turbulence in the gas disks around young stars. He says there are many possible routes for turbulence. Too much, in fact, for him to work alone, which is why there is collaboration between different universities. Each node in the network collaboration will study one of the processes and how they work to concentrate dust to form planets. Ultimately, they will combine their research to come up with a unified theory.
The project also has an educational component focused on underserved adolescents in the region, with the aim of encouraging them to pursue higher education. Lyra and her team will develop a science camp where students will learn to reason and learn astronomy. The project plans to reach Hispanic adolescents living below the poverty line in the Las Cruces region.
Lyra started such a program when he lived in Rio de Janeiro while other colleagues pursued him in Nigeria and Bangladesh. Now that schools have reopened in Las Cruces, he plans to move closer to schools in that region. In three years, he thinks he can reach a significant percentage of Hispanic teenagers in Las Cruces.
âIf you ask a scientist why he chose his career, more often than not it was an event, a time when their horizons widened,â Lyra said. âMaybe we watched a rocket launch, for others it was a movie. I got interested when I was 5 years old. I saw a drawing of the solar system and it got me hooked. From that moment, I wanted to know everything about it. These events can spark lifelong interest. This is what we want to replicate by inspiring these kids with interesting science. “
Source: Minerva Baumann, New Mexico State University