A Jesuit brother needed by NASA for his meteorite mastery

Bro. Bob Macke SJ is playing a pivotal role in one of NASA’s most recent groundbreaking successes, writes Jason Osborne

The word ‘cosmos’ comes from a Greek root meaning ‘order’. With so many in this present age accustomed to linking the enormity of space with ‘chance’ or chaos, it may come as a surprise to find a Jesuit brother who puts God front and centre right at the heart of one of humanity’s most advanced scientific undertakings.

Bro. Bob Macke SJ is working alongside some of the world’s foremost scientists as part of NASA’s Osiris-Rex mission. ‘Osiris-Rex’ means ‘Origins, Spectral Interpretation, Resource Identification and Security – Regolith Explorer’. A bit of a mouthful? The mission description should clear things up:

“Osiris-Rex is the first US mission to collect a sample from an asteroid. It returned to Earth on September 24, 2023, to drop off material from asteroid Bennu. The spacecraft didn’t land, but continued on to a new mission, OSIRIS-APEX, to explore asteroid Apophis. Meanwhile, scientists hope the Bennu sample Osiris-Rex dropped into the Utah desert will offer clues to whether asteroids colliding with Earth billions of years ago brought water and other key ingredients for life here.”

That makes the whole affair sound quite matter-of-fact, but the reality is that it was a mission years in the making and unfolding, the product of unparalleled scientific and technological expertise, that was in no way a guaranteed success. Launched from Cape Canaveral in Florida in 2016, the spacecraft travelled to a near-Earth asteroid named Bennu (formerly 1999 RQ36) and collected a sample of rocks and dust from the surface in 2020.

The term near-Earth is a tricky one. On a cosmic scale, Bennu is indeed ‘near-Earth’, but it might come as a surprise to find out that Osiris-Rex still had to travel 200 million miles, or 320 million kilometres in order to rendezvous with its target asteroid.

Epic

So how does a Jesuit brother come to find himself at the heart of such an epic project? Well, the very first step along that path was an early love of science, Bro. Macke tells me.

“I have always been fascinated with learning about this incredible universe that we live in. Before I became a Jesuit, I studied physics at MIT and started graduate studies at Washington University in St Louis. At Washington U, I studied presolar grains, which are micron-sized grains of dust that formed in stars and other astrophysical environments, and somehow survived the formation of our solar system intact, still retaining information about the environments where they formed,” Bro. Macke says.

My work has given me a bit of a reputation as the expert on meteorite density and porosity”

“By studying them in the laboratory, we can constrain our models of the stars and other objects where they formed. These dust grains are found in certain kinds of primitive meteorites, and so I began to learn about meteorites at that time.

“Long story short, I left graduate studies to discern my vocation as a Jesuit brother. I entered the Society of Jesus a couple years later. Later one summer, Brother Guy Consolmagno (then-curator of meteorites) invited me to visit him in Rome to study the meteorites of the Vatican collection. Little did I know that he was looking for his eventual successor. This led eventually to finishing my PhD at the University of Central Florida and my joining the staff of the Observatory in 2013. I became curator of meteorites a year later.”

It’s easy to see how expertise in meteorites might come in handy for a mission like Osiris-Rex, but to give a more precise picture of what that work consists of, Bro. Macke tells me exactly what his area of expertise is: “I study the physical properties of meteorites, in particular density and porosity (the amount of void space inside the rock), though lately I have also been working with thermal properties. In my research, I have systematically studied these properties in meteorites from numerous collections around the world, creating a database that other researchers have found valuable for their own models of asteroid structure, formation, and behaviour.”

Fascinating

There are many scientists working in this fascinating field, so how did Bro. Macke find himself picked out of the crowd to assist such a high-stakes mission? His expertise in measuring these “precious” space rocks was what set him apart.

“My work has given me a bit of a reputation as the expert on meteorite density and porosity. When the sample analysis plan for the specimens from Bennu was being developed, one of the working group leads contacted me for advice about measuring the density and porosity of these precious space rocks. It was not long before he asked me to join the sample analysis team in order to develop and run an instrument for measuring densities,” Bro. Macke says.

“This device, called an ideal-gas pycnometer, performs the measurements without altering or destroying the specimen, which is important, but they wanted to go further; it had to keep the specimens in their pristine state, just as they were when collected, which meant making a device suitable for a sealed clean room glove box at NASA Johnson Space Center.”

The device could only be made from a short list of approved materials, Bro. Macke says, and had to mount to a porthole on the side of the box which “complicated the design considerably,” to say the least. It was “quite a relief” when they mounted it to the glove box and everything matched up perfectly and worked as it was designed to.

“Soon I will be conducting the measurements myself in Houston, and my data will provide valuable insight as to the nature of these rocks before they go off to be studied in more detail by a large team of other researchers worldwide,” Bro. Macke says.

It may provide some insight as to whether the building blocks of life formed on Earth or whether they might have been delivered to Earth by asteroids”

As mentioned in the mission description above, scientists had high hopes that the sample collected from Bennu would offer clues as to whether asteroids colliding with the infant Earth billions of years ago brought water and other “key ingredients” for the life that, obviously, developed here.

The news was warmly welcomed then when NASA announced October 11 that initial studies of the 4.5-billion-year-old sample revealed evidence of a high-carbon content and water “which together could indicate the building blocks of life on Earth may be found in the rock,” as the press release accompanying the announcement stated.

While Bro. Macke can’t comment on scientific results beyond what has been publicly revealed to this point, he did clarify what exactly the goals for the mission were, and what thoughts the presence of carbon and water stimulated in the many minds of the scientific community.

“Among the important goals of the Osiris-Rex mission we want to understand better both how Earth got its water and how the building blocks of life originated. This particular type of asteroid, which is very carbon-rich, may have provided raw materials for the building blocks of life. We look forward to detailed studies of amino acids and other complex carbon molecules in these samples. It may provide some insight as to whether the building blocks of life formed on Earth or whether they might have been delivered to Earth by asteroids,” he says.

“In addition, it is hypothesised that the water in Earth’s oceans may have been delivered by asteroid impacts in the very early history of the solar system. This water is not stored in liquid form; instead it is trapped in the chemical structure of what are called hydrated minerals. These minerals are abundant in the Bennu specimens, and by studying them we can get a better sense of just how much water an asteroid contains.”

Contradict

Many of faith might be troubled by reports that the building blocks of life came from elsewhere. Does that not seem to contradict what Genesis tells us about the origins of life on earth? However, commenting on the successful return of the Bennu sample back in September, one of Bro. Macke’s colleagues, Bro. Guy Consolmagno told The Irish Catholic that because God is truth itself, people of faith ought never be afraid of the truth, whether that be scientific, supernatural or otherwise.

“God is truth; so if you really want to get close to God you need to find the truth that’s actually there, not the ‘truth’ we hope for or the ‘truth’ we are afraid of.

“So there’s no particular result, for example regarding the origins of life, that would be ‘better’ or ‘worse’ for religion. Rather, no matter what we find, we’ll find God regardless in the joy of discovery and the elegance of the way that the Creator actually made this wonderful universe,” the papal astronomer told this newspaper in September.

It’s a view Bro. Macke comfortably espouses too, having had much time to reflect on the relationship between science and faith. “By studying the wonders of God’s creation,” he tells me, “we can better appreciate the God who created it”.

“In 1935, Pope Pius XI gave the Vatican Observatory its motto: “Deum Creatorem Venite Adoremus” (“Come let us adore God the Creator”). This sums up our motivation at the Observatory. By studying the wonders of God’s Creation, we can better appreciate the God who created it. In short, for us, doing science is a form of worship,” he says.

When I saw some stones on the mylar flap of the TAGSAM head with my own eyes, I reminded myself that I was looking at pristine pieces of an asteroid that a human-built spacecraft went out into space to collect and bring back to the Earth”

“I bring that perspective into all the scientific work that I do, and this research is no different. This does not change the actual scientific work itself, merely the context.”

And what scientific work this has been. Humanity’s first ever asteroid sample collected in space. I asked Bro. Macke how he felt on the day the sample was safely and successfully returned. How did it feel to take part in something humans had never done before?

“The day of the landing, I attended a watch party at the former Osiris-Rex headquarters in Tucson, Arizona, where we could watch a live feed of the landing and recovery operations. I was very excited to see the parachute deploy, and later to see the capsule nested safely nose-down in the soft soil. I was anxiously looking forward to seeing what treasures were trapped inside,” he says.

“This mission collected by far the largest quantity of asteroid material to date, and would provide an opportunity for an incredible amount of scientific exploration about this particular kind of asteroid, which may provide valuable insights for the early history of water and building blocks of life on the Earth. I was fortunate enough to be at NASA in Houston during the early operations in which the canister was opened to reveal the collection unit (called the TAGSAM head) and learn with much relief that the rocks it contained stayed largely intact through the rather violent process of atmospheric entry.

“When I saw some stones on the mylar flap of the TAGSAM head with my own eyes, I reminded myself that I was looking at pristine pieces of an asteroid that a human-built spacecraft went out into space to collect and bring back to the Earth. I felt a lot of pride at the accomplishment, though I had little to do with it.”

Asked about whether he has any guesses as to what further analysis of these unprecedented samples might reveal, Bro. Macke says that if they knew, then it wouldn’t be worth studying them.

Valuable

“The most valuable revelations are precisely those things that we did not anticipate. I do not know what the specimens might reveal, but I look forward to finding out.”

For the next two years, the scientists assigned to the mission will continue characterising the samples they’ve collected and continue conducting analysis to see what else can be discovered. NASA plans to preserve at least 70% of the sample at the Johnson Space Center in Houston, Texas, for further research by scientists worldwide, including future generations of scientists who’ll have access to better, more accurate technologies.

The science programme that follows is an international effort that will see more than 200 scientists around the world exploring the sample’s properties, including researchers from many other US institutions, as well as other countries’ space agencies, such as JAXA (Japan Aerospace Exploration Agency), CSA (Canadian Space Agency), and many other scientists from around the world. Further samples will be going on display in various locations around the US for the public’s consideration.