Tag Archives: space

Uncharted territory: how big is the universe?

How far is too far? On groggy Sunday mornings, the gym may seem “too far”, while for two long-distance lovers separated by circumstances, they are always “close enough”. For some, distance is relative to our motivation. Space, however, does not care what you think.

Voyager 1. Image from NASA.

It’s been over 35 years since NASA’s launch of Voyager 1, and since then, it has travelled almost 20 trillion kilometers from home. You might think that that’s far, but in the grand scheme of the universe where distances are measured with respect to light, it has travelled a mere 18 light-hours. To put that into perspective, the nearest star to our Sun, Proxima Centauri, is about 4.24 light-years away.

So how big is the universe then?

Before we address that, we need to know how old the universe is. Based on measurements of the cosmic microwave background, which is basically leftover radiation from the Big Bang, astronomers are confident that the universe is about 13.8 billion years old. Since Distance = Velocity × Time and nothing can travel faster than light (?), the universe must have a radius of 13.8 billion light-years, right? Wrong!

The Doppler effect on the pink sound waves. Image from user Charly Whisky from Wikipedia.

The short answer to the size of the universe is that it is at least 93 billion light-years in diameter. The reason that the universe is larger expected is because the universe is expanding. This can be determined by the apparent redshift of distant stars due to the Doppler Effect. So an object emitting light from 13.8 light-years away would have moved to a position much farther away.

One thing to note, is that this measurement is only what we can observe.  The observable universe from another planet billions of light-years away is likely different from our reference frame of the Earth. Is the universe infinite? Perhaps. But for now, we can appreciate that even though our paradigm of the universe is limited, there is still much to explore; we have observed billions of galaxies, and in each are billions of stars, each hosting their own worlds much like ours. Despite the uncertainty in the true size of the universe, we know that space is vast. As the Dutch artist Vincent van Gogh had once said, “for my part I know nothing with any certainty, but the sight of the stars makes me dream.”

If you have 45 minutes to spend exploring part of our Solar System, check out Alphonse Swinehart’s video below, where you travel from the Sun to Jupiter at the speed of a photon! Do yourself a favour and enjoy the video in full screen mode.

– Trevor Tsang


Life on Mars? – The Key to Survival on The Red Planet

Science is all the rage in the film industry these days, with films like Interstellar proving to be massive hits both critically and in the box office.  Consequently, The Martian is hoping to capitalize on that success. This science fiction adventure is based on a best-selling book written by Andy Weir and features Matt Damon as Mark Watney, a botanist turned astronaut who finds himself stranded on Mars after an intense dust storm forces his crew to evacuate the planet. The film follows his quest to survive alone on a barren wasteland and his attempts to contact Earth and seek rescue.

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Credit: 20th Century Fox

While scientifically feasible and chock full of technical jargon, The Martian is a fictional story by all accounts. After all, humans can’t be expected to grow potatoes inside a tiny habitat for long term survival, as Mark Watney does in the film. But is life on Mars a reachable short term goal? At least one team of researchers thinks so, and they believe they have unearthed the key.

Cyanobacteria By Doc. RNDr. Josef Reischig, CSc. (Author's archive) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

By Doc. RNDr. Josef Reischig, CSc. (Author’s archive) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Astrobiologist Cyprien Verseux and his team at NASA’s Ames Research Center have discovered a way to use cyanobacteria in order to sustain a long-term human presence on Mars, which was previously thought to be unrealistic due to the amount of resources that would have to be sent.

The idea of cyanobacteria in outer space research is not new. Humans have already been using microbes to search for life on Mars, as illustrated in the video below:

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Credit: Open University

Cyanobacteria not only have the ability to survive and grow in Mars simulated conditions, as determined in a study by Karen Olsson-Francis, but they can also fix carbon from carbon dioxide (CO2) and create useful nitrate from dinitrogen (N2), which Mars has plenty of in its atmosphere. While we can’t actually survive simply off of eating cyanobacteria due to their lack of vitamin C and overabundance of vitamin A, they can be used to feed microorganisms, which can then be utilized to convert biomass into potentially fertile soil. Aquaculture is also a possibility, as crustaceans and shellfish are already feeding off of cyanobacteria as a main food source.

Furthermore, Verseux also explored the prospect of using cyanobacteria to produce oxygen, finding them to be even more efficient producers than fully grown trees. Cyanobacteria were even able to produce components of biofuel that could be used to power vehicles and equipment as illustrated in a study by Daniel Ducat; however, further advances must be made for either of these applications to come to fruition.

Often times we watch these ambitious science fiction movies thinking that they’re simply the pipe dream of an idealistic filmmaker. But just as screenwriters are dreaming up new frontiers to impress and amaze audiences, scientists are working diligently in the background to make those frontiers a reality.

To infinity and beyond!

Mars Exploration Rover By NASA/JPL/Cornell University, Maas Digital LLC [Public domain], via Wikimedia Commons

Mars Exploration Rover
By NASA/JPL/Cornell University, Maas Digital LLC [Public domain], via Wikimedia Commons

 Tim Cheung