Radio·Bob McDonald's blog

Terra Incognita: Continuing to explore the great unknown

Robotic spacecraft are carrying on the tradition of past explorers who ventured out over the horizon to see what's there.
Yutu-2, China's lunar rover, leaves wheel marks after leaving the lander that touched down on the surface of the far side of the moon. (The Associated Press/China National Space Administration/Xinhua News Agency)

Ancient maps often had blank regions on them labelled "terra incognita" for regions that had yet to be explored. Since then, the Earthly maps have been filled in, but new unknown lands are now being explored in space.

The new year began with a bang with three exploratory missions into new territories that included landing on the far side of the moon, the first encounter with a Kuiper Belt object far out beyond Pluto, and orbiting around an asteroid. All of these robotic missions are carrying on the tradition of explorers from the past who ventured out over the horizon just to find out what is there. It is an important part of the human spirit to explore, and it adds valuable knowledge to the nature of the universe around us.

The far side of the moon is literally out of sight to us because the moon is gravitationally locked with the Earth, so it always keeps one side facing toward us and the other side facing away as it swings around our planet every month. Many moons in the solar system do this. And while the lunar far side has been photographed from orbit and the Apollo astronauts gazed down upon it, China's Chang'e-4 probe is the first to actually land there and explore it in detail.

The far side of the moon (Apollo 16 crew, NASA)

It is hoped that the mission will help to answer the question of why the other side of the moon is so different from the side we see. Rather than the large smooth regions, such as the "sea" of Tranquility where Neil Armstrong and Buzz Aldrin made the first boot prints 50 years ago, the other side of the moon is completely covered in craters and highlands. In fact, the region is so rough, the Chinese engineers had to improve the accuracy of their landing system so Chang'e-4 could find a safe place to touch down. It's as though the moon has a smooth face staring at us and a rough back of the head.

New Horizon's encounter with Ultima Thule is a journey into a realm of ice worlds known as the Kuiper Belt, that was not even included in early maps of our solar system. It was only spotted in the 1990s, yet, this band of millions of flying icebergs completely surrounds all the planets. New Horizons began to explore this region in 2015 when it flew past Pluto, which is now considered just one of the larger members of the Kuiper Belt.

The first colour image of Ultima Thule, taken at a distance of 137,000 kilometers on January 1, 2019, highlights its reddish surface. (NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

The Osiris-Rex mission to asteroid Bennu is exploring another belt of debris, mostly made of rock that circles the sun between the orbits of Mars and Jupiter. While other asteroids have been visited by spacecraft, this mission will be the most detailed ever and includes bringing a sample of the asteroid back to Earth.

After a two-year chase, a NASA spacecraft has arrived at the ancient asteroid Bennu, its first visitor in billions of years. (NASA/Goddard/University of Arizona via AP)

Venturing into terra incognita has traditionally been done to find resources in other parts of the world, often at the expense of Indigenous populations. Fortunately, there are no inhabitants in space that we know of, and there are resources such as water on the moon, precious metals in asteroids, and possibly clues to the origin of life in icy Kuiper Belt objects. But the real goal is the pursuit of knowledge just for the sake of knowing it. And when it comes to the rest of the universe, most of it is still unknown, so there is a lot of territory to cover.

Space exploration is often criticized as having no practical application, a waste of money when there are so many problems to solve here on Earth. First of all, compared to the amount of money we spend on entertainment, sports, booze, and inventing creative ways to shoot each other, the space program is cheap. In Canada, it works out to be about $10 per person per year. And as far as applications go, much of our highest technology, such as GPS communication, comes from space. But at a more fundamental level, primary exploration not only tells us what is out there, it is also a look back in time.

The OSIRIS-REx spacecraft traveled to the asteroid Bennu and will bring a sample back to Earth for study as seen in this NASA artist rendering. (NASA/Reuters)

Asteroids and Kuiper Belt Objects are leftover remnants from the primordial cloud of gas, dust, and ice that gave birth to the sun and all the planets billions of years ago. They are the crumbs left on the table after the pie has been placed in the oven. Examining those crumbs gives us the ingredients that were in the original recipe. In other words, by exploring deep space, we are looking into our own past to trace the history of how we got here.

Primary exploration, to boldly, or meekly go where no one has gone before, is the very essence of basic science. Asking simple questions such as, "What are things made of?" or "How do things work?" have led to some of the greatest leaps of thought. If we stop exploring, stop asking those basic questions, we will stop growing, and will have lost the spirit that has always pushed humans over the next horizon unto the exciting world of the unknown.

About the Author

Bob McDonald is the host of CBC Radio's award-winning weekly science program, Quirks & Quarks. He is also a science commentator for CBC News Network and CBC-TV's The National. He has received 12 honorary degrees and is an Officer of the Order of Canada.


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