Examining our place in the galaxy

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By John Hughes

Anyone who has ever gazed skyward on a clear summer night, or perhaps looked at imagery from the Hubble telescope, or even watched the famous Monty Python sketch about the insignificance of Earth in the cosmic scheme might well have wondered where they fit in the universe. It’s a problem that has engaged philosophers, theologians and scientists for millennia. Today an astronomer at the Peter Wall Institute is working toward a better understanding of the quandary. Enter Professor Aaron Boley of UBC’s Department of Physics and Astronomy. A Wall Scholar since September 2016, Professor Boley’s work aims at understanding how our earthly standpoint came to be:

“My research has focused on different pathways for planet formation, trying to explain the different ways that planetary systems altogether can form—not just the Solar System but the many different planetary systems that are now known in the galaxy, and trying to put that all into context. Studying the formation of meteorite components provides clues as to what happened here in the Solar System.”

­A lot of the awesome astronomical events that we see in space are vast and in some ways disconnected from our experiences. Planetary astronomy is a way to bridge that gap by impacting our society in ways the aren’t readily apparent.

“Astronomy goes into our music, into our literature, into our theatre,” Professor Boley explains. “Our very sense of time is based on astronomy. The way our cultures have evolved over time have dealt with trying to cope with our place in the universe, our place in the Solar System. The study of planet formation is in many ways an origin story. It’s trying to understand, from a scientific point of view, how this human experience came to be.”

Asteroid collision

Planets, including those like our own Earth, form from epic collisions between asteroids and even bigger bodies, called proto-planets. Sometimes the colliding bodies are ground to dust, and sometimes they stick together to ultimately form larger, mature planets. Image: NASA/JPL-Caltech

Investigating the possibility of extraterrestrial life 

As astronmers gain a greater understanding of planetary systems it turns out that there is much in common among them.

“If you look out and see a star, it may very well have a planet,” Dr. Boley says. “However, what we don’t know yet, is if you take all the different types of planetary systems, how often is there a planetary system which is stable and suitable for hosting life? And this can be bacteria. It doesn’t have to be an extremely complex organism—one capable of complex thought.”

World-class astronomers will explore some of these questions at a conference that will be funded in part by the Peter Wall Institute. The Chondrules as Astrophysical Objects conference will address whether chondrules are byproducts or building blocks of the Solar System.

“Chondrules are these 0.1 to 1 millimetre once-molten spherules,” says Professor Boley. “These are objects that are found in abundance in our meteorites. And these chondrules, these little grains, are all flash-heated, melted, cooled individually, while orbiting in the gaseous, dusty disc that eventually formed all the planets. One of the reasons I think chondrules are so fascinating is that they’re actually a piece of time that we can hold onto. They are basic components of planet building. We’re hoping chondrules might help us understand how planets form.”

Meteorite

In this slice from the 4.5-billion-year-old Allende meteorite all of the small round objects are chondrules. The large irregular whitish objects are Calcium-Aluminium-rich Inclusions, the oldest solids in the Solar System.

The conference takes place at the Peter Wall Institute from May 9-11, 2017 and will feature some unexpected means of examining cosmic processes. Conference attendees will be able to ‘listen’ to the stars.

“If you could take a time series of data, for example, to observe changes in the amount of light that you receive from a star over time, one way to represent that is to take the frequency and turn it into something that you would hear,” Dr. Boley says. “In some ways, sound can give a much better appreciation of the way data are changing than if you are looking at, say, a light curve. Sometimes features can be more dramatic when you hear them than when you see them.”