Published by the SPT, a student society of McGill University
Keep on Commuting
April 5, 2022
Gino McTuff’s journey to the library
March 29, 2022
A conversation with Ehab Lotayef: A lifelong voyage to the conscience of humanity
July 28, 2026
SPHR remembers Gaza Solidarity Encampment ahead of Nakba Anniversary Protest
May 13, 2026
Every semester, members of the McGill community travel outside of Canada to study abroad, take part in field research, or engage in other educational opportunities. In an email addressed to students abroad on March 14, McGill Abroad recalled all students currently on exchange due to the ongoing COVID-19 epidemic. The university’s announcement followed the Public Health Agency of Canada’s decision that same day to identify all countries as Level 3 (avoid non-essential travel outside Canada) on the level-of-risk scale, which ranges from Level 1 (practise usual precautions) to Level 4 (avoid all travel).
On March 16, Prime Minister Justin Trudeau announced that Canada would ban entry to all people who are not Canadian citizens or permanent residents as of noon on March 18, prompting McGill to urge all foreign nationals who wish to return to Canada to make travel arrangements immediately in an email on March 16. Furthermore, the Canadian government announced the creation of the COVID-19 Emergency Loan Program for Canadians Abroad, aimed to provide financial assistance in the form of an emergency loan to Canadians needing to purchase airline tickets home.
All McGill students on exchange had to decide whether to go home to their families or remain at their host universities.
Daniel Minden, U2 Arts, was on exchange at Sciences Po in Paris, France when he was recalled by McGill. He returned to his family in Toronto on March 16. In a message to The McGill Tribune, he explained the financial burdens associated with booking flights on such a short notice.
“Since both universities and governments are urging Canadians to get home as soon as possible, flights are extremely expensive,” Minden wrote. “I paid $2,000 for a flight from Paris to Toronto (via Montreal), and I have friends who have paid up to $4,000. It’s an enormous, unexpected sum of money to pay as a student.”
Others have arranged their flights home and will be departing shortly. This is the case for Zoe Babad-Palmer, U3 Arts, who had their exchange in Norway cut short. They booked a flight home to New York this week, which they had to rebook a couple times due to the cancellation of their connecting flight. Babad-Palmer messaged the Tribune about the concerns they had about taking this trip.
“I am very very worried, especially about the wait times,” Babad-Palmer wrote. “I’m worried about extra border controls, if I can reach my connection in time or if it’ll mess up my baggage. Everyone’s seen that photo of people packed in like sardines at Chicago O’Hare[,] and I’m very worried about that[,] because we’re trying to not get sick[,] and being squished in with hundreds of people for hours and hours is not the best way to do that.”
Due to these concerns, some exchange students have chosen to stay at their host universities. Twyla Schran, U2 Arts, is staying in Brisbane, Australia to continue their research at the University of Queensland on the Great Barrier Reef.
“The entire point of coming to Australia in the first place was to get field opportunities that McGill does not provide anymore,” Schran wrote to the Tribune. “If I return home without completing the research, I would most likely have to go abroad [again] later on for the same reasons [….] Overall, it’s literally safer for me to be here than at home, and the fact that McGill wants me to return anyways shows that they care more about their control than the individual situations for each student.”
The recurrent sentiment expressed by exchange students has been disappointment with McGill’s handling of the crisis, pointing to the lack of communication with students abroad specifically.
“Originally I was just gonna wait it out, and then things got worse so I decided to leave,” Babad-Palmer wrote. “That was a decision that my family and I made on our own, not really with anything from McGill. We waited so long to hear anything, […] especially [since] Norway and the UK and the Netherlands were all taking different precautions, and McGill put them all under the same umbrella of ‘wait and see’.”
Meanwhile, some exchange students have found McGill’s response more proactive than their own host university, as Emma Ayache, U3 Management, told the Tribune.
“I think that they sent a lot of emails and are very responsive to the ones I sent,” Ayache said. “[…] I know that I am back home but that’s not going to be a problem and I’m going to be able to finish my semester, and I regularly talk with my advisor who’s very responsive. So, I think that McGill is really doing a good job, especially when I compare it to my university in Spain that barely gives any news.”
A conversation with Ehab Lotayef: A lifelong voyage to the conscience of humanity
July 28, 2026
SPHR remembers Gaza Solidarity Encampment ahead of Nakba Anniversary Protest
May 13, 2026
According to an email co-signed by the Senior Director of Student Housing and Hospitality Services (SHHS) Marisa Albanse and Deputy Provost (Student Life and Learning) Fabrice Labeau, practicing social distancing during the COVID-19 crisis in large student residences is difficult due to the nature of co-living. As a result, students residing in McGill housing have been asked to return home in a March 18 email. While usually students commit to paying rent for the duration of their leases, Frédérique Mazerolle, Media Relations Officer for McGill University, said that the SHHS will not penalise students for moving out early.
“Students who move out of residence will have their lease cancelled effective their departure date,” Mazerolle wrote in an email to the McGill Tribune. “Rent will not be charged from the day students move out.”
In a subsequent email, SHHS cancelled all gatherings and parties in residences. Further, guests have been banned in all residences, and all athletic centres in residence halls have been closed per provincial directive.
The letter acknowledged that international students living in residence may be unable to return home, given new travel restrictions from various national governments. Students that are not moving out are asked to continue practising social distancing; students who believe they have been exposed to SARS-COV-2 are asked to report themselves to their residence director so that they can be provided accommodations such as food during self-isolation.
McGill has announced in a Facebook post that no exams will take place in person for the Winter 2020 semester. As well, the academic term will not be extended: Classes will end on April 14, and the exam period will end on April 30, both as scheduled.
“The alternative assessment plan will be communicated before the end of March,” the post read.
In a joint agreement between Canada and the US, people will no longer be able to cross the border for non-essential travel, such as tourism or business. Canadian citizens will still be allowed to return home. These restrictions will not apply to international students, workers on visas, and those who must cross the border to do essential work and maintain supply chains.
Starting March 18, anyone who is not a Canadian citizen or permanent resident will be barred from entering the country. Exceptions apply for diplomats and aircrews. Anyone with flu-like symptoms, regardless of citizenship, will not be allowed to board a plane to Canada.
A conversation with Ehab Lotayef: A lifelong voyage to the conscience of humanity
July 28, 2026
SPHR remembers Gaza Solidarity Encampment ahead of Nakba Anniversary Protest
May 13, 2026
As exchange students have their semesters abroad cut short and return to Canada, five students from the Department of Earth and Planetary Sciences and their professor were stuck in Morocco for five days after travelling there for a two-week geology field research excursion on February 27. After several complications, the group was able to secure one of the last outbound flights out of Morocco and is currently making their way back to Montreal. However, the two international students in the group have been denied plane boarding even though the government of Canada announced that visa holders are allowed back into the territory.
The students—Julia Morales-Aguirre, U3 Science; Robert Collar, Masters Science; Joshua Wasserlauf, U2 Science; Kaiyuan Wang, U1 Science; and Emilie Saucier, U2 Science, along with their Professor Anthony “Willy” Williams-Jones—were prevented from leaving the country on March 14 as a result of recent travel restrictions and flight cancellations.
Due to the remote nature of the trip, the group only learned of the severity of the pandemic on March 13, when they were making their way to Tangier airport to fly back to Montreal through Casablanca. The government of Morocco cancelled flights to select countries on March 14, including Canada, so the group secured a new trip to Montreal but all inbound and outbound international flights were suspended on March 15. After the group successfully booked a direct flight from Casablanca to Montreal for March 21, it was cancelled on March 17.
Julia Morales-Aguirre, U3 Science, wrote to The McGill Tribune that the group has been in constant communication with their departmental chair at McGill, receiving moral and financial support.
“The chair of our department, Professor Jeffrey Mackenzie, has been in contact with us since the initial flight ban to Canada on Saturday night,” Morales-Aguirre wrote. “He immediately told us that the department would pay for everything: Flights, accommodation, [and] food, [and] that the priority was to get home. The entire Earth and Planetary Science Department has been providing moral support. They have also been making arrangements should we remain stranded, such as giving us credit for receiving lessons while here.”
The group consisted of four Canadians, one American, and one Chinese citizen. Without knowing how much longer they would have to stay in Morocco, they booked an Airbnb until mid-April so that they could stock up on food.
“Essentially, our professor [had] been paying most of [our expenses and will be] reimbursed by McGill,” Morales-Aguirre wrote. “We [were] in an AirBnB in Casablanca […] There [was] no quarantine yet [there] for everyone, but the city now [had] a curfew.”
The group garnered media attention after creating a Facebook, Twitter, and Instagram page dedicated to their situation. Getting them home was a team effort between Professor Williams-Jones’ sons and others close to the group and the EPS department at McGill. EPS Outreach Administrator Kristyn Rodzinyak wrote to Tribune about the close-knit nature of the department and how they were able to provide moral support to the group all the way from Montreal.
“With the closure of McGill, […] I started a virtual cookie time where students, faculty, staff and alumni can join a virtual meeting on zoom as a way to connect during social isolation,” Rodzinyak wrote. “During a virtual cookie time[,] two of the students in Morocco checked in from a restaurant where they were picking up food for the rest of the group. They were in good spirits, [and] were excited to share their favourite sites and rock collecting adventures. […] It was really nice for faculty and students back in Montreal to get to see their smiling faces and hear about their adventures.”
Professor Anthony Eric Williams-Jones’ son, Glyn William-Jones, a geology professor himself at Simon Fraser University, spoke to The Tribune about how they were able to coordinate a big group of people to work together across time zones through social media. His Montreal-based brother, Bryn, also started a petition which reached over 13,000 signatures in three days. The goal was to urge the Canadian government to repatriate the group, as well as other Canadians who are still stuck abroad.
“I think one of the really crazy [things], and why I’ve been ranting on LinkedIn and Twitter and my brother [has been] doing the same thing on Facebook, is that Canadians have had to do it themselves,” Glyn William-Jones said. “[…] The Canadian Embassy [in Rabat] wasn’t doing anything. They were just like, ‘You’re on your own, get yourself home however you can, not our problem’.”
Before the group’s return trip had been secured, Morales-Aguirre also expressed her frustrations regarding the Canadian government to The McGill Tribune.
“The passivity of the Canadian government vis-[à]-vis their people abroad is upsetting,” Morales-Aguirre wrote. “[…] It is absurd to tell people to come home when airports and borders all over the world are closing. People literally cannot get on commercial flights, which is the only thing that the Canadian embassy has been recommending. Flights are getting cancelled left and right, and bookings are disappearing everywhere you look.”
On Facebook, the group indicated that they had contacted Nolinor Aviation, an airline providing rescue missions for Canadians abroad, but the tickets from Casablanca to Montreal set to leave on March 20 would have cost the group $8,000 each.
Eventually, the group was able to catch one of the last flights out of Morocco to London with Ryanair on March 18, from where they were able to depart for Montreal on a British Airways flight on March 19.
“Even on the drive to Marrakech [on March 18], they found on the internet that apparently the flight had been cancelled but they just decided […] to push through and the flight hadn’t been canceled,” Glyn Williams-Jones said. “This is a happy ending for this small group and I’m super happy, this is family. But at the same time, it’s one tiny drop in the bucket of all the other Canadians that are trapped.”
Currently, Professor Anthony William-Jones and the two international students in the group are stuck at Heathrow Airport in London because border control there is refusing to let the American and Chinese student board, even though they have Canadian study permits to study at McGill.
“We are incredibly frustrated,” Glyn William-Jones wrote to the Tribune. “[…] The McGill team that made it onto the flight (Canadian students) feel guilty for being forced to leave their friends. Instead of returning home together and triumphant after such an ordeal, they are divided and distraught.”
Follow the group on Facebook for the latest updates.
urban child
November 15, 2025
Hundreds attend counter-protest for transgender rights, in photos
September 30, 2025
Students protest for Palestine at Parliament, in photos
June 21, 2025
Our multimedia team stopped by Building 21, a research and community space on McGill campus and talks to their team about their initiatives, projects, and visions.
Video by McGill Tribune Multimedia Team.
How can I show you I’m doing better if there’s nothing good for me to do?
April 13, 2026
Your health, your problem
April 8, 2026
On becoming Chinese
March 30, 2026
I grew up as an athlete, playing competitive basketball and soccer on school and community teams. I never thought much about my body or what I ate until I tore my anterior cruciate ligament (ACL) in 2015 while playing basketball. During the rehabilitation process after my knee surgery, I committed to a rigorous physiotherapy routine and felt compelled to go to the gym every day. I desperately wanted to be back with my teams as soon as possible, and as a result, found myself absorbed into a vicious routine of fitness and dieting. I thought I was making healthy choices, however, those choices, along with pressures from social media, soon began to dictate my life.
The World Health Organization declared COVID-19 a global pandemic on March 11. As of press time, the coronavirus had rapidly spread to more than 175,000 people in 162 countries and caused nearly 7,000 deaths.
Doctors Michel Chrétien and Majambu Mbikay, senior researchers at the Montreal Clinical Research Institute (IRCM), have proposed the use of a plant-based compound called quercetin to treat COVID-19. Clinical trials to test its effectiveness are scheduled to start in China within the next few weeks.
Chrétien and Mbikay say that quercetin, which some research suggests can protect against the Ebola and Zika viruses, may be able to treat the coronavirus. Working with Chinese health officials, they will supervise clinical trials for testing the drug on patients in China. They will use the drug produced by the Swiss company Quercegen Pharmaceuticals, which, according to Chrétien, produces the purest available quercetin. The trials will last around four months.
Present in many fruits, vegetables, seeds, leaves, and grains, quercetin is a compound that originates from flavonoid plants. It is non-toxic for humans and can be purchased over the counter as a dietary supplement.
Chrétien and Mbikay’s interest in quercetin started in the 1990s, when they screened for mutations in gene PCSK9, a master regulator of cholesterol in circulation. They realized that children with less functional PCSK9 are less susceptible to malaria, which motivated them to look for a natural oral compound to inhibit PCSK9 functioning.
“We were looking for the compound […] that could be ingested and inhibit PCSK9 and cause a decrease [in] blood cholesterol,” Mbikay said. “What we observed is that [quercetin] was a very potent inhibitor of PCSK9. In other words, it could lower cholesterol.”
They then investigated quercetin’s inhibiting effects on parasites, bacteria, and viruses, especially after the outbreaks of the SARS-CoV and Ebola viruses in 2003 and 2018, respectively. These investigations unravelled the pivotal role of quercetin not only as an anti-metabolic compound through affecting PCSK9 and lowering cholesterol but also as a potential antiviral agent that targets the entry process of viruses.
During the last decade, research by Chrétien, Mbikay, and colleagues has suggested that quercetin can protect mice from Ebola and Zika viruses. After the recent COVID-19 outbreak, they proposed quercetin to Chinese health officials as a potential wide-spectrum antiviral drug.
“A cell has a lock, and the virus has a key [to enter and infect the cell],” Chrétien said “But quercetin puts glue in the lock.”
As of Feb. 15, China planned to run more than 80 clinical trials to treat COVID-19, testing a variety of potential remedies, such as HIV drugs, stem cells, and traditional Chinese medicines. Chrétien explained that quercetin has three advantages over other candidate treatments: It is taken orally; it is a natural, plant-based product; and it is relatively cheap.
“[Quercetin] costs peanuts compared to the antivirals that are on the market, which cost sometimes $1000 [per] shot,” Chrétien said. “Two months ago, you could have a one day treatment [of over-the-counter quercetin] for two dollars.”
On March 4, the Lazaridis Family Foundation contributed $1 million to support this project. Chrétien says that this suffices for the first one or two months of the project but estimates that they will need $5–6 million per year.
“We are asking our government to give us money to guide the Chinese,” Chrétien said. “I think our government will gain a lot […] not only on the health of people, but [in] their relationship with China.”
However, the world must wait four months to know whether quercetin cures or prevents COVID-19.
“The worst thing in medical science is to give false hope,” Chrétien said.
‘You are what you eat’: It is an idiom many have heard in trendy food advertisements or in their grandparents’ kitchen. But, for scientists, this common phrase has been proven in the now extensive body of research known as gut microbiomics. Aiding in digestion, producing certain vitamins, and even assisting with weight loss, the assorted collection of bacteria and viruses that live inside humans known collectively as the ‘gut microbiome’ can be helpful or potentially harmful. A recent study published in Cell Host & Microbe documents a novel link between the gut microbiome and stunted childhood growth. Specifically, researchers examined the presence of bacteriophages, pathogenic viruses that attack and live inside bacteria in the gut, and their prevalence in the stomachs and intestinal tracts of children who have experienced stunted growth.
While previous studies have focussed primarily on the composition of bacteria and viruses in the gut, Dr. Corinne Maurice, professor in the Department of Microbiology and Immunology at McGill, turned her team’s attention toward bacteriophages, which often go overlooked in analyses of the gut microbiome. By using bacteriophages, also referred to as phages, as a molecular marker for the presence of bacteria in the guts of healthy and stunted children, researchers could compare the development of the gut microbiome across various stages of microbial succession.
The study found no significant difference in the number of phages in children’s guts. Yet, a metagenomic analysis of the bacteriophage DNA, a process that entails the isolation and identification of certain viral DNA sequences, lead to a breakthrough.
“We saw that stunted and healthy children had different phage communities,” Maurice said in an interview with The McGill Tribune. “For example, stunted kids had more proteobacteria phages, proteobacteria being those pathogens [that] make us sick, while non-stunted children had phages [that] infect bacteria in older children and adults.”
For children growing up in countries that lack adequate access to food and medical care, the age at which they become malnourished or develop juvenile infections can make all the difference in their likelihood of becoming stunted. To identify bacteriophages, McGill researchers used fecal samples collected from children in Bangladesh, where rates of malnutrition and stunted development are among the highest in the world.
“Food insecurity and pathogen exposure such as diarrheal infections can lead to stunting,” Maurice said. “This, for example, is what is happening with these children in Bangladesh. These kids, before they turn five years old, may have already had three to five diarrheal infections per year.”
Under such conditions, children are often given nutritional therapies in the form of vitamins and protein supplements, which work for a short period of time but are ultimately unsuccessful and only lead to a delay in growth. Now, as Maurice explained, the failure of nutritional therapy alone can be more aptly attributed to the gut microbiome, which does not respond as readily to dietary changes in the later years of adolescence.
According to Maurice, the notion that the gut microbiome is in some way linked to delays in childhood development such as stunting is a fairly new idea.
“Most therapeutic interventions, historically at least, did not consider the gut microbiome because […] we had no knowledge that the gut microbiome played a role,” Maurice said.
Previously, it was thought that children had up to three years after birth to establish their gut microbiome. In the study, however, McGill researchers identified a shorter window of opportunity, where, if children are able to maintain a healthy diet, the adverse effects of stunting on growth during adolescence may be avoided.
“What we found looking at the phages was that the time frame of intervention may be different than we initially thought and is closer to between zero and two years of age,” Maurice said. “[…] Our older children, [who] were between 28 [and] 38 months, were not able to easily change their [gut] communities.”
The emerging field of microbiomics is still a long way away from putting an end to childhood stunting, but the work of Maurice and her team shows that sometimes answers to the most pressing questions can be found in the least explored places.
A new study published in The Canadian Journal of Psychiatry sheds light on the relationship between brain development and behavioural disorders such as inattention-hyperactivity disorder, a condition similar to Attention Deficit Hyperactivity Disorder (ADHD).
“The term inattention-hyperactivity, as defined in this study, refers to a set of behaviours such as fidgeting and lack of concentration that were rated by regular classroom teachers using a questionnaire,” Guido I. Guberman, lead author of the study and a medical student in McGill’s Department of Neurology and Neurosurgery, wrote in an email to the The McGill Tribune. “Although children with a diagnosis of ADHD will display inattentive and hyperactive behaviours, the children in our study who displayed inattention-hyperactivity did not necessarily have diagnoses of ADHD.”
Guberman and his colleagues were interested in the effect of inattention-hyperactivity on the brain development of young boys. To answer this question, researchers conducted a longitudinal cohort study, making several observations of the same subjects over 28 years. The McGill team began by collecting data on a group of 10-year-old boys through interviews with their teachers. In the following years, they collected data from the cohort’s official health records until they were 34 years old.
The findings suggest that boys who display inattention-hyperactivity at age 10 are at an increased risk of developing traumatic brain injuries (TBIs), such as concussions and brain contusions, in adolescence and adulthood.
“The official definition [of traumatic brain injuries] is a disruption in the normal structure and function of the brain as a result of an external mechanical insult,” Guberman wrote.
Current knowledge of traumatic brain injuries suggests that they have a wide variety of potential causes, as well as numerous effects on brain health and function.
“They can vary in severity, on one end being mild [like concussions], and on the other end being fatal,” Guberman wrote. “There are many causes, including falls, motor vehicle accidents, sports accidents, and assaults. Even mild TBIs can have consequences that are lifelong.”
The study also found that boys who experienced a TBI before the age of 10 were more likely to develop TBIs in adolescence but not adulthood. Boys who displayed externalizing behaviours—being antisocial or aggressive towards others rather than internalizing their feelings—before the age of 10 were also more likely to develop TBIs in adulthood only.
The results of this study are incredibly concerning for children and their parents. Past research has shown that TBIs and attention disorders can have negative impacts on a child’s development.
“Previous studies have found differences in white-matter structure in children with diagnoses of ADHD,” Guberman wrote. “One hypothesis we have is that boys who display inattention-hyperactivity end up engaging in more risk-taking behaviours in adolescence, such as driving fast [or consuming] drugs and alcohol [and] engaging in fights.”
Unfortunately, few treatments exist for TBIs. Currently, scientists are exploring active physical rehabilitation therapies for sports-related concussions, but the number of treatment options are few. Therefore, prevention of TBIs is key to mitigating the negative consequences of brain injuries later in life.
“It is important to minimize the risk of TBIs by promoting safe riding strategies (on bicycles and motor vehicles) and by minimizing practices that lead to brain injuries in sports,” Guberman wrote. “Future research [also] needs to explore other ways of reducing the incidence of TBIs by identifying and addressing risk factors.”
Our solar system has existed for roughly 4.5 billion years—a long time, especially given that humans have only walked the Earth for the last 300,000 years. To gain an understanding of the solar system as a whole, scientists often follow clues that offer insights into the history of the universe. Such clues often come in the form of space rocks, which tell us a lot about the origin of our solar system and how it was when it took shape.
There are three main types of space rocks: Asteroids, comets, and meteoroids. Though the terms are often used interchangeably, the rocks themselves are vastly different.
Much smaller than planets, asteroids are rocky objects that orbit the Sun. They are composed of rocks and metals left over from the formation of the four planets closest to the Sun—referred to as the inner solar system—when a huge cloud of dust and gas collapsed to form the giant star. Unlike most spherical space bodies, asteroids are oddly shaped, with craters and erratic orbits. Ranging from the size of a boulder to hundreds of kilometres in diameter, they inhabit a region between Mars and Jupiter known as the Asteroid Belt, where they are sometimes pulled into Earth’s orbit. Ceres, often called a dwarf planet, is the largest known asteroid in the Asteroid Belt, measuring almost 1,000 kilometres across.
Apart from gaining information on the chemical and physical properties of asteroids, NASA’s missions to study these objects have been essential in detecting the locations of other asteroids and predicting the potential dangers that they pose to Earth.
Ranging from the size of a house to 10 kilometres in diameter, comets are composed of not only rock and dust, but ice and gas as well. Scientists believe that they originate in the Oort Cloud, a very cold region that surrounds the solar system, and the Kuiper Belt, which lies just beyond Neptune. Comets are believed to be remnants from the formation of the outer planets: Jupiter, Saturn, Uranus, and Neptune. Although they were formed around the same time as asteroids, comets were created in colder regions of space where water could freeze.
Comets orbit around the Sun, but in a more elliptical manner than their asteroid counterparts. When pulled in a closer orbit, the icy nucleus of the comet starts to evaporate, and the ice and gasses boil off and surround the nucleus to form a cloud called a coma. The dust and gas is pushed away from the coma by solar winds to form the tail of the comet, which can reach up to 150 million kilometres long. Each time the comet passes close to the Sun, it loses some of its material. Over time, it will break up and disappear completely. If it intersects Earth’s orbit, the dust and debris left in the comet’s wake will fall into the Earth’s atmosphere, becoming meteoroids.
Smaller than an asteroid or comet, a meteoroid is a chunk of rock that orbits the Sun and has broken off from a comet or asteroid. When a meteoroid enters Earth’s atmosphere, the friction causes a streak of light and vaporizes the meteoroid to form a meteor, which is also known as a shooting star. Meteor showers describe the phenomenon of several meteoroids burning up in Earth’s atmosphere. If the meteoroid survives its journey through Earth’s atmosphere and lands on the ground, it is termed a meteorite.
According to NASA, while 100 tonnes of tiny dust and sand particles attack Earth every day from outer space, meteorites the size of a football field only hit Earth once every 2,000 years. Every few million years, a space rock large enough to threaten civilization comes along. Scientists estimate that the two-billion-year-old Vredefort crater in South Africa, now 100 kilometres wide, was originally three times that size.
Large or small, space rocks do not generally pose a threat to humans. Rather, they serve as important tools for scientists to understand our solar system and beyond.
