A network of cameras directed by Western University observed a bright fireball across southern Ontario at 7:23 p.m. on Wednesday, January 24. Analysis of the video data by Western scientists suggests that fragments of the meteor are likely to have made it to the ground between the communities of Saint Joseph and Crediton, Ontario.

Western’s Physics and Astronomy Department runs a camera network that constantly monitors the sky for meteors. Peter Brown, a leading expert in the study of meteors, confirmed that the January 24th event was a meteor as 12 of the all-sky cameras from Western’s Southern Ontario Meteor Network (SOMN) recorded a bright fireball over western Ontario.

“This fireball was particularly significant because it ended very low in the atmosphere just to the north of Grand Bend, a good indicator that material survived. In fact, it was still producing light at 24 kilometres altitude,” says Brown. “In fact, the only deeper penetrating fireball we have ever detected was the Grimsby meteorite-producing fireball of September 25, 2009.”

According to Brown, other factors, which strongly favour survival of meteorites, are the very low entry speed (only 13 km/s) and the steep entry angle (about 27 degrees from the vertical). These factors strongly suggest small meteorites made it to the ground.

“This event is very important because we have good quality video data of its passage through the atmosphere and hence know where the rock comes from in our solar system,” says Brown. “Meteorites are also of great interest to scientists like me as studying them helps us to better understand the formation and evolution of the Solar System,” says Brown.

Preliminary results indicate that the fireball first became visible at an altitude of 75 kilometres and travelled almost due north. The initial mass is believed to be several kilograms, leaving approximately tens to hundreds of grams of material on the ground.

Brown and the rest of the Western Meteor Physics Group are very interested in speaking with anyone in the area of the potential fall, who may have heard or seen anything unusual, or who may have found possible meteorites.

Meteorites can be recognized by their dark, often scalloped, exterior. Usually they are denser than a ‘normal’ rock and will often be attracted to a magnet due to their metal content. Meteorites are not dangerous, but if recovered, it is best to place them in a clean plastic bag or wrap them in aluminum foil. They should also be handled as little as possible to help preserve their scientific value. In Canada, meteorites belong to the owner of the land upon which they are found. If individuals plan to search, they should always obtain permission of the land-owner before venturing onto private land.

If you have any questions, observations, or have found a suspicious rock from this event, please contact Michael Mazur from the Western Meteor Physics Group at mmazur5@uwo.ca or 250-551-6426.

For video footage, still images and site maps, please visit
http://meteor.uwo.ca/research/fireball/events/grandbend

MEDIA CONTACT: Jeff Renaud, Senior Media Relations Officer, 519-661-2111, ext. 85165, 519-520-7281, jrenaud9@uwo.ca

ABOUT WESTERN
Western University delivers an academic experience second to none. Since 1878, The Western Experience has combined academic excellence with life-long opportunities for intellectual, social and cultural growth in order to better serve our communities. Our research excellence expands knowledge and drives discovery with real-world application. Western attracts individuals with a broad worldview, seeking to study, influence and lead in the international community.

Western researcher Philip Stooke may soon get his own television series – CSI: The Moon – if he keeps uncovering mysterious crash sites on the omnipresent astronomical body.

The Geography professor’s latest finding closes a decade-old mystery about the final resting place of SMART-1, the European Space Agency’s first lunar mission sent into a controlled impact with the Moon in 2006, three years after its launch in 2003.

“The investigation was purely mine,” Stooke said. “Other people had looked for it, and I had in the past as well, both without success.”

The investigation started with Stooke updating maps in his 2007 book, The International Atlas of Lunar Exploration, with images from the Lunar Reconnaissance Orbiter (LRO), a NASA craft that has taken the most detailed images of the Moon to date.

Using those images, Stooke stumbled across the 2009 crash site of a Chinese spacecraft, Chang’e 1. While looking for signs of its crash, he found a few odd-looking craters. To check them, he looked at old images taken by Apollo 16 in 1972.

“The images showed the craters I had found were all there long before Chang’e 1 crashed. But as I compared the images, I noticed a bright spot not present in the old images. That was the crash site (of Chang’e 1),” he said. “It had exactly the characteristics expected of an object hitting the Moon at a very shallow angle, almost grazing the surface, slower than meteorites would hit it.”

Unlike the circular craters created by fast-moving objects like meteorites, slow-grazing impacts cut linear gouges in the surface of the Moon, throwing out debris, or ejecta. Whereas fast impacts throw that ejecta out in all directions, slow-grazing impacts tend to throw it only downrange, forming a fan of ejecta in the direction the object was travelling.

Sensing he may be on to something, Stooke focused his attention on trying to locate SMART-1.

“We knew roughly where SMART-1 was. And I looked in the expected location – but now looking for a fan of ejecta extending from a rather elongated crater, more like a gouge in the surface as you might expect from a grazing impact,” he said.

The initial distribution of ejecta was observed by the Canada-France-Hawaii Telescope in 2006. But an exact location was never determined – until now.

“I found it quickly now because I knew better what to look for,” said Stooke.

He showed his findings to Bernard Foing, the European Space Agency project scientist in charge of the mission, when he visited Western this spring. He agreed it was indeed the site.

Stooke said solving this ‘lunar cold case’ holds more historical significance than it does scientific implication.

“Lunar exploration is one of the big things nations have been involved with in the last half century, and many aspects of its history have yet to be told,” he said. “That’s one of the goals of my book. This work forms part of the record of human activity in space. There may be a bit of science to come out of it, as well.”

Stooke has also been looking for the impact sites of the Apollo Lunar Module upper stages. After the Apollo astronauts returned to orbit and joined up with their orbiting spacecraft for return to Earth, the Ascent Stage of the Lunar Module was abandoned. Some of them were crashed to create a signal for seismometers on the surface.

“They have been very elusive, but I think I now have three of the four we might find,” he said.

It was a stroke of serendipity that led to Michael Zanetti’s discovery of the hottest rock on Earth.

In 2011, Zanetti, now a postdoctoral researcher in Earth Sciences at Western, was on an analog mission with Earth Sciences professor Gordon Osinski at 28-kilometre-wide Mistastin Lake crater in Labrador – a Canadian Space Agency (CSA)-funded endeavour using the impact structure as a test bed for exploration strategies and field equipment for use on the moon and Mars.

A PhD student at Washington University in St. Louis at the time, Zanetti’s eye honed in on something that stood out within the crater.

“My role was basically to assist the mock astronauts and take notes. Being a wide-eyed graduate student, I kept my eyes open for interesting rocks and things like that,” he said.

“Being an impact crater guy and being in one, I was super excited. When I was out there, I found a rock that didn’t look in place. It was essentially glass – which, in geotechnical terms, is a rock – that didn’t have any crystals in it. It melted. Before it had a chance to form any little crystals in it – which form slowly as things cool – it cooled rapidly and quenched a glass,” he explained.

When a city-sized asteroid hits the ground at 15 km/second, an enormous amount of energy is released, like “a billion hydrogen bombs worth of energy,” Zanetti said.

This produces a lot of heat – so much heat, you could vaporize rocks. The rapid cooling that follows impact ‘freezes’ in place whatever is inside the rock. In the case of the glass rock that caught Zanetti’s eye, small zircon grains from the host rocks were frozen in place.

Zircon – a mineral known by many as a cheap diamond substitute – doesn’t break easily and doesn’t melt, even at temperatures hot enough to melt surrounding rocks. Instead, the zircon grains present in host rocks recorded the heat at the time of the asteroid’s impact 38 million years ago.

The rock Zanetti found recorded the hottest temperature in a rock formation on Earth as a result of the asteroid impact – a whopping 2,370 C.

“The big picture here is this – very hot temperature is at the centre of the Earth; it is unusual here. There are hot temperatures and high pressures down deep in the Earth but not at the surface of the Earth,” Zanetti said.

“You’ve got these little zircons floating around (in this rock). They’re feeling the effects of this heat and one of the effects of this very high heat on zircon is to change its crystal structure to cubic zirconia. This little zircon inside this little sample I found records that; it got frozen in place by quenching to glass halfway through. If it had gone on another couple of seconds, the heat might have just completely engulfed this grain. But this is just kind of a rare happenstance that it got frozen halfway completed.”

An analysis of the rock, and this record-breaking temperature, led by Nicholas Timms at Curtin University in Perth, Australia, co-authored by Zanetti and colleagues in Switzerland and the United States, was recently published in the journal Earth and Planetary Science Letters.

The crux of the science behind this discovery is that it closes the gap between computer models, Zanetti explained.

“We can do the math on what happens, and how much energy is really released when a giant asteroid hits the ground really fast, and we can get estimates on what these temperatures should be, and where in the crater these temperatures should be found. But what we have now is an actual hand specimen that we can say, ‘This came from this place and it got this hot,” he said.

The entire reason this rock was found was because of a Western-led CSA-funded expedition for something completely unrelated, Zanetti stressed.

“I didn’t set out to find a hot rock. The other part of this is how lucky things can get. One, I was lucky to get on that mission, lucky to get this rare sample, lucky when I cut into it that I cut across one of these rare zircons, lucky that I was with a team of people who could identify it for what it was and lucky to find the right people to analyze it,” he noted.

“Sometimes it takes just a bit of happenstance to find some cool things.”

Thirty-two students from Western and around the world will be journeying almost two billion years back in time in a unique, intensive one-week field course to study the planet’s second-largest impact crater.

Prof. Gordon (Oz) Osinski, acting director of Western’s Centre for Planetary Science and Exploration (CPSX), will lead a graduate class to the Sudbury Crater, a terrestrial motherlode for space enthusiasts, in a field school to study impact craters.

“There’s no other field course in the world that focuses on impact cratering as this one does,” he said. “You can learn only so much from viewing a crater on a satellite image, watching a presentation or reading a book. Here, we glean information about impact craters that you can understand only from boots-on-the-ground. It provides an unparalleled glimpse into one of the world’s largest impact craters that then helps us better understand our solar system.”

The field course is a partnership with Western’s CPSX, the Lunar and Planetary Institute (LPI) and the Solar System Exploration Virtual Institute (SSERVI) at NASA’s Ames Research Center in California’s Silicon Valley. The course is part of a series of field training programs the LPI created through NASA’s Lunar Science Institute and SSERVI programs. LPI, through its Center for Lunar Science and Exploration program led by David Kring, provides administrative and financial support. Kring, an expert in impact cratering who has also studied the Sudbury impact structure, is a co-instructor with Osinski, who is also Director of the Canadian Lunar Research Network. 

The Sudbury Basin was formed about 1.85 billion years ago when a comet slammed into Earth, leaving an astronomical wealth of mineralogical and geological information for modern-day scientists to discover and examine.

The class includes 15 Western students and students from the US, Belgium, and Alberta — all selected in a competitive process. “We’re not just supporting and teaching graduate students at Western but enabling other students to take this course, while continuing to build a hub of expertise at Western.”

“As NASA celebrates 59 years of space exploration, training the next generation of scientists is obviously vital to our future,” said Greg Schmidt, Deputy Director of SSERVI and Director of International Partnerships. “Partnerships like the one we have with Canada through Western University provide a great opportunity for students to learn in the field while strengthening our own important ties with international researchers and collaborators.”

Starting on Sunday, Osinski and the class will be tweeting their journey and discoveries through #SudburyImpact.

MEDIA CONTACT: Debora Van Brenk, Media Relations Officer, Western University, 519-661-2111 x85165, or on mobile at 519-318-0657 and deb.vanbrenk@uwo.ca

ABOUT WESTERN: Western University delivers an academic experience second to none. Since 1878, The Western Experience has combined academic excellence with life-long opportunities for intellectual, social and cultural growth in order to better serve our communities. Our research excellence expands knowledge and drives discovery with real-world application. Western attracts individuals who have a broad worldview and who seek to study, influence and lead in the international community.

 ABOUT LPI: The Lunar and Planetary Institute (LPI), a division of the Universities Space Research Association, was established during the Apollo missions to foster international collaboration and to serve as a repository for information gathered during the early years of the space program. Today, LPI is an intellectual leader in lunar and planetary science. The Institute serves as a scientific forum attracting world-class visiting scientists, postdoctoral fellows, students, and resident experts; supports and serves the research community through newsletters, meetings, and other activities; collects and disseminates planetary data while facilitating the community’s access to NASA science; and engages, excites and educates the public about space science and invests in the development of future generations of explorers. The research carried out at LPI supports NASA’s efforts to explore the solar system.

ABOUT SSERVI: NASA’s Solar System Exploration Research Virtual Institute (SSERVI) is based and managed at NASA’s Ames Research Center in Moffett Field, California. SSERVI is a virtual institute that, together with international partnerships, brings science and exploration researchers together in a collaborative virtual setting. SSERVI is funded by the Science Mission Directorate and Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington.