3 things you should know about home composting, the Moon-bound Space Launch System rocket, and the science behind dark circles under your eyes

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Meet Renée-Claude Goulet, Cassandra Marion, and Michelle Campbell Mekarski.

They are Ingenium’s science advisors, providing expert scientific advice on key subjects relating to the Canada Agriculture and Food Museum, the Canada Aviation and Space Museum, and the Canada Science and Technology Museum.

In this colourful monthly blog series, Ingenium’s science advisors offer up quirky nuggets related to their areas of expertise. For the May edition, they explain the key to successful backyard composting, the burnt orange colour of NASA’s Space Launch System that is gearing up to return humans to the Moon, and the science behind the dark circles under your eyes when you are tired.

A bowl of food scraps being poured into a wooden bin already containing semi-decomposed food scraps

A common mistake in home composting is adding too much wet, nitrogen-rich materials and not enough dry, carbon-rich materials to balance it out.

The key to home composting is in the recipe

Gardening season is finally upon us, and a critical step in the spring is replacing nutrients in the soil that were taken up by your plants last season. A great way to do this is by adding compost to the garden. But the cost of store-bought compost can add up over time, so why not try making your own?

Compost made from your food scraps, yard trimmings, grass clippings, and fallen leaves can give an added boost to your plants, and provide great benefits for the soil and the life it hosts. Compost serves as a slow release fertilizer and soil conditioner because it is low in available nutrients but rich in organic matter.

The organic matter in compost is in very small pieces called humus (not hummus, pronounced hue-mus), which feeds soil microbes and other soil organisms, propping up their populations. A healthy microbe community in the soil benefits the whole garden, because they help protect plants from disease and pests, and play an essential role in cycling nutrients that plants need, as seen in the nitrogen cycle. Organic matter and a well-fed soil ecosystem create porous soil that absorbs and retains water well, resists erosion, and sustains plants.

So what should go in a composter? The thing to know is that there are two main categories of compost “ingredients.” The nitrogen-rich material, which we’ll call “greens” and the carbon-rich material, which we’ll call “browns.”  Greens are things like food scraps, fresh plant material, and manure. Browns are things like straw, dry leaves, cardboard, and wood chips. The key to successful composing is adding the right ratio of browns to greens. Too many browns and the composting will slow to a crawl, too many greens and your compost will be a pile of slime and stink.

Researchers have determined that 30 parts carbon to one part nitrogen creates the most balanced compost. Be careful though, this doesn’t mean adding 30 handfuls of browns for every handful of greens. Different materials have different carbon to nitrogen ratios. For example, for wood chips it’s around 500:1 and table scraps, about 15:1. You can consult this table found here to find out how to achieve the best mix, based on what you plan to feed you composter.

For every addition of greens, cover with a layer of browns, creating layers in your heap. Topping with a layer of browns will also help keep any critters at bay and, over time, help create pockets of air within the heap.

So, whether you are a seasoned gardener or just starting out, it’s never too early or too late to try your hand at composting, and it doesn’t need to be complicated! Experiment and get the feel for your heap and in time, you will be rewarded with “black gold,” made from something that would have otherwise been bagged up and thrown away!

By Renée-Claude Goulet

A huge orange rocket core stands between two white rocket boosters on a mobile launch vehicle, illuminated by spotlights against a black background.

The Space Launch System rocket and Orion spacecraft atop a mobile launcher at the Kennedy Space Centre, Florida before its wet dress rehearsal in March 2022.

NASA’s giant orange Moon rocket is almost ready

The Space Launch System (SLS) is a huge rocket destined to return humans to the Moon as part of the Artemis Program — an international multi-mission campaign led by NASA.

SLS is the modern, more powerful counterpart of the Saturn V rocket that launched the Apollo capsule between 1969-1972. Similarly, the SLS will launch the Orion capsule into space and set it on a course for the Moon. The simplest variation of the SLS rocket stands 64.6 m tall, 8.4 m wide and weighs 70 metric tons!

The system consists of a core stage with four RS-25 main engines – updated versions of the main engines on the Space Shuttle – two solid rocket boosters, an exploration upper stage, a service module, the Orion crew vehicle which can comfortably fit 4 astronauts, and a launch abort system.  

The core stage is like the brains of the rocket. It hosts the power and batteries, flight computer, cameras, and the fuel. The burnt orange colour is the natural colour of the foam insulation that covers the vehicle’s cryogenic liquid hydrogen and oxygen tanks. The Space Shuttle’s external fuel tank was orange too for the same reason. Originally painted white, engineers determined that the UV protection the paint provided the Shuttle’s tank on the pad wasn’t necessary. For SLS, the lack of paint will significantly reduce the mass of the vehicle resulting in easier production and an increase in the payload it can carry to space.

In March 2022, the SLS was rolled outside to the launchpad for a major readiness test called a wet dress rehearsal.  The rehearsal was designed to practice countdown procedures such as loading and unloading propellant and verifying all the rocket’s systems. The test was cut short as it identified a series of issues. The rocket has now returned to the Vehicle Assembly Building at NASA’s Kennedy Space Centre in Florida for repairs and planning is underway for the next dress rehearsal.

The SLS’ debut launch for the Artemis I mission is scheduled for no earlier than August this year. It is an uncrewed test flight that will launch the Orion capsule on a path around the Moon and back to Earth. If Artemis I is successful, Artemis II will repeat the Artemis I mission but with a crew of four astronauts on board: three Americans and one Canadian. The long-awaited Moon landing mission, Artemis III, is set to launch by 2026. In the latter case, Orion will rendezvous with the Lunar Gateway, a pre-positioned space station around the Moon, where crewmembers transfer to the lunar lander system to descend to the lunar surface. 

Stay tuned for this exciting launch in the near future!

By Cassandra Marion

A seated women sits in a dark space, slouched over, resting her face on her hand. She is frowning slightly as she looks to the side, her eyes are partly shut, she has dark circles under her eyes, and she looks generally exhausted.

Lack of sleep doesn’t just cause dark circles, it can cause some pretty serious health issues too!

Dark circles under your eyes: the science behind why you look tired

What do exam-cramming students, parents with newborn babies, and late-night Netflix binges have in common? A lousy night’s sleep, and dark circles under the eyes the next morning. 

Dark, puffy patches under the eyes are a common side effect of fatigue, especially from a lack of sleep. They’re like big, dark flags announcing that, right now, you probably need either an espresso shot or a nap. But what are those dark circles? What you’re actually seeing is a physiological response to your body trying to keep you awake.  

When you’re tired, your body releases a hormone called cortisol (also known as the stress hormone) to try to keep you awake and alert. Cortisol has a number of effects on your body, but one effect is an increase in blood volume. More blood means your blood vessels stretch to accommodate it. 

Below the eyes, your skin is very thin compared to the rest of your body. This means that blood vessels – and any changes occurring in your blood vessels – are much easier to see. When your blood vessels are extra full (thanks to fatigue-induced cortisol) you can see the extra blood flow visible as dark, bruise-like patches.

It’s important to note that fatigue is not the only thing that can give you dark circles under your eyes. Dark circles under the eyes are genetically linked and can run in families, and they do get worse with age as under-eye skin gets even thinner. Dark circles under eyes can also be caused by illness, allergies, and lifestyle choices: sun and cosmetics can damage skin around the eyes, and alcohol and salt consumption can cause stretched-out blood vessels in the same way that cortisol does. 

Dark circles under the eyes are a common and natural part of the face, but they can be indicative of a deeper health issue: chronic fatigue. Even one bad night of sleep can cause a pretty serious ‘sleep hangover’ the next day, causing irritability, reduced immune function, forgetfulness, food cravings, and clumsiness. However, a chronic lack of sleep can lead to increased risk of obesity, high blood pressure, diabetes, cancer, cardiovascular disease, memory loss, premature aging, and workplace injuries.

It’s recommended that adults 18-64 years old get 7-9 hours of sleep a night, and 7-8 hours after the age of 65. However, a third of Canadians regularly sleep less than this. It can be difficult to get enough sleep – especially with work and family care responsibilities – but a good night’s sleep is key to good health, and can help with those dark circles.  

Go further:

Why is sleep so important? Plus, some day-to-day actions you can practice to prioritize healthy sleep

Are Canadians getting enough sleep?

By Michelle Campbell Mekarski

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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.

Profile picture for user Cassandra Marion
Cassandra Marion, PhD

Cassandra is the Science Advisor for the Canada Aviation and Space Museum. She has a PhD in geology and planetary science and exploration. Her research is focused on meteorite impact craters in the Canadian Arctic. She has more than a decade of experience in education and public outreach, developing and delivering science programming. She is dedicated to sharing her passion for Earth and planetary sciences with communities near and far, and improving science literacy in Canada.

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Renée-Claude Goulet

Renée-Claude is the Science Advisor at the Canada Agriculture and Food Museum, and an Ontario Certified Teacher. Through her background in biology, education and many years of experience creating and delivering programs and exhibits at the museum, she has developed an expertise in communicating key issues related to the science and innovation behind production of food, fibre and fuel, to a wide range of audiences.