Oct 2, 2019

An extra-solar visitor

An object that likely originated from outside the solar system was recently discovered by an astronomer in Crimea.

All objects in the Solar System — the planets, moons, asteroids, and comets — are bound to the Sun by gravity. The Sun’s gravity determines the orbits of everything, so if you want to leave the Solar System, you need to have enough velocity to escape the gravity of the Sun. Humans have actually done this a few times; the most well-known examples are the two Voyager probes, launched in 1977, which are on escape paths out of the Solar System.

Aside from human-made objects, anything native to the Solar System is bound to the Sun. Since we understand the relationship between gravity and orbital velocity, when something doesn’t fit, it sticks out like a sore thumb! Recently, an astronomer noticed a small, comet-like object tracking across the sky. Using many observations, a preliminary orbit was determined for the object, and thus its velocity relative to the Sun.

Surprisingly, this object’s orbit has both a velocity that is larger than the Sun’s escape velocity, and a trajectory that’s sending it out of the Solar System. That means it likely originated from outside the Solar System.

This is actually the second interstellar object discovered; the first was discovered in 2017 and is now called ‘Oumuamua. When it was discovered, astrophysicists predicted that there were many other such objects flying through our solar system. This new discovery seems to confirm that hypothesis.

Asteroids and comets are often touted as time-capsules: unprocessed material left over from the beginning of the Solar System. We study asteroids and comets because they tell us about the conditions of the early Solar System. Interstellar asteroids and comets would teach us the same things, but regarding other stellar systems from whence they came. This will allow us to compare and contrast solar systems — without having to fly to other places.

By Jesse Rogerson

Seven different open-pollinated tomato varieties from the Canada Agriculture and Food Museum’s garden, displaying a range of colours, sizes, and shapes.

A colourful collection of open-pollinated varieties of tomatoes, grown in the garden at the Canada Agriculture Museum in summer 2019. From left to right; Amethyst Cream, Adelaide Festival, Mini Rose, Petit Moineau, Rideau Sweet, Ottawa, and Kangaroo Paw Green.

Hybrids or heirlooms: Saving seeds from the garden

Fall is upon us! In our gardens at the Canada Agriculture and Food Museum, annual crops are giving their last go at reproduction before the frost hits. Gardeners may now be wondering: can I keep seeds from my plants to use next year? The answer is: it depends!

When assessing whether to keep seeds from a plant, the main thing to consider is whether the plant is a hybrid, or an open-pollinated variety of the species (i.e. species – tomato, variety – “Roma”). Hybrid varieties, like the “Early Girl” tomato, occur when plant breeders cross-pollinate two distinct and inbred varieties of the same species, in controlled environments. The resulting offspring inherit the best traits from each parent. Advantages include fruit uniformity, high yield, and resistance to certain pests. However, planting seeds saved from hybrid varieties will seldom yield desirable results. When a hybrid plant breeds, the traits achieved through hybridization are passed on but do not manifest to the same degree in the offspring; what grows will not be like the parent plant.

On the other hand, we have open-pollinated varieties, which include what is known as heirlooms. These varieties rely on insects and wind for pollination, contain more genetic variability, and tend to retain their traits from generation to generation, even without much human intervention — other than separation from other varieties of the same species. Heirlooms, like the popular “Brandywine” tomato, are simply open-pollinated varieties that were passed down through generations and predate the era when hybrid varieties were introduced.

Open-pollinated varieties offer variable fruit quality and lower yield than in hybrids, but they are often known to have more flavor and to display interesting colours and shapes. These are the seeds you should keep, as the offspring will feature the same splendor as the parents!

Of course, this is just a very brief overview of what to save and what to let go of. To learn more about seed saving in the garden, consult the Community Seed Network.

By Renée-Claude Goulet

Rows of green bins line a rainy residential street, awaiting collection.

Photo Credit

Wikimedia Commons

Rows of green bins awaiting collection.

Plastic fantastic or pulp fiction?

In July 2019, the City of Ottawa joined a small, but growing number of cities including Edmonton, Alberta and London, Ontario that are allowing plastic bags to mix with domestic organic waste.

Reading that, you’re probably having the same reaction as many Ottawa residents did when they first heard the news. You may be wondering, “How does that work? Plastic doesn’t decompose!” or “Why does this decision make any sense?” Let’s explore.

“How does that work? Plastic doesn’t decompose!”

True! But the plastic doesn’t end up in the compost. When Ottawa’s organic waste arrives at the waste facility, it goes through a shredder (like a giant paper shredder). This shredded mixture of fresh organics and plastic is mixed with older organic waste that has already started to decompose, and is therefore full of microbes. Like a colony of space explorers settling a new planet, the microbes quickly colonize the new waste, multiply, and quickly get down to the business of decomposing our kitchen garbage. After seven to 10 days, almost everything that can decompose has broken down into small pieces, while the things that can’t (plastic, glass, rocks) stay the same size. The mixture goes through a rotating sieve that separates the big things (i.e. shredded plastic bags) from the small things. Another separator takes the remaining small pieces and separates them based on density. Heavy material (glass, stones, etc.) gets removed, while lighter material (organics) is put aside to decompose for another three weeks before it is tested for pathogens and contaminants, and sold as compost.

“Why does this decision make any sense?”

So the plastic bags get removed from the compost…but why allow them in the first place? Bottom line: to recycle more compostable waste and keep it out of landfills. It’s estimated that almost half the waste Ottawa produces could be composted, but most of it isn’t going into green bins! Many residents don’t use green bins, and those that do still end up throwing some biodegradable material in the garbage. Why? It may be due to the “yuck” factors: yucky brown goop, yucky smell, yucky maggots. The city is predicting that by allowing plastic in green bins, the “yuck” factors will be reduced, encouraging more people to make better use of green bins.

It’s not a perfect plan. With these new policies, the city is arguably perpetuating the use of plastic in the economy, and it is possible that more plastic fragments could end up in the soil. However, by attempting to divert hundreds of thousands of tonnes of waste from the landfill and promoting soil recovery by adding compost, the city is making a commitment to a more sustainable future. Time will tell if the strategy works; hopefully this marks the start of more Canadians opting in on composting — giving some much-needed waste relief to our overtaxed environment.

By Michelle Campbell Mekarski

Looking to read more quirky science nuggets? Check out the “3 things you should know” Board.

Author(s)

Jesse Rogerson, PhD

Jesse is a passionate scientist, educator, and science communicator. As an assistant professor at York University in the Department of Science, Technology, and Society, he teaches three classes: History of Astronomy, Introduction to Astronomy, and Exploring the Solar System. He frequently collaborates with the Canada Aviation and Space Museum, and lends his expert voice to the Ingenium Channel. Jesse is an astrophysicist, and his research explores how super massive black holes evolve through time. Whether in the classroom, through social media, or on TV, he encourages conversations about how science and society intersect, and why science is relevant in our daily lives.

Michelle Campbell Mekarski, PhD

As the Science Advisor at the Canada Science and Technology Museum, Michelle’s goal is to bridge the gap between the scientific community and the public — specializing in making science and technology engaging, accessible, and fun. Michelle earned a PhD in evolutionary biology and paleontology and has many years of experience developing and delivering science outreach activities. When away from her job at the museum, she can be found teaching at the University of Ottawa or Carleton University, digging for fossils, or relaxing by the water.

Renée-Claude Goulet

Renée-Claude Goulet is the Science Advisor at the Canada Agriculture and Food Museum, with over 15 years of experience in science communication. At the Museum, she develops exhibitions, educational programs, and resources that explore the science and innovation behind agriculture and food production. An Ontario Certified Teacher with a BSc in Biology and a BEd in Sciences, Renée-Claude is passionate about making complex topics accessible and engaging for all audiences.