Category Archives: Science

The Red Planet

This year, the ExoMars Trace Gas Orbiter was launched to discover if there is life on Mars. What will they find? In anticipation of the Oribiter’s arrival in October (and the article in Maybe’s upcoming print issue), here are some facts about the Red Planet.

As the fourth planet in the solar system, Mars has a longer year than Earth, taking 687 days to orbit the sun. Interestingly, its days are only 40 minutes longer than ours, but if humans ever get to set foot on Mars, they are unlikely to feel at home there.

Mars is a perishingly cold, dry, barren planet with a thin atmosphere that is 95% carbon dioxide, meaning that we would find the air impossible to breathe. Its distinctive reddish colour is caused by the rust that covers its surface. By day the sky is also red, while the sunsets are blue – an extraordinary sight that was captured on the camera of NASA’s Curiosity Rover.

If you stood on the dusty plains of Mars and looked into the night sky, you would see two moons: Phobos and Deimos. Scientists believe that within the next 20-40 million years, Phobos will be torn apart by gravitational forces, leaving a ring like the rings of Saturn.

Although Mars is the second smallest planet in the solar system, it is home to its tallest mountain: Olympus Mons, a volcano three times higher than Everest. The lava flows around it are so recent that scientists think it may still be active.

The elliptical orbit of Mars results in extreme seasonal change. Its dust storms are the largest in the solar system, sometimes lasting for months and engulfing the entire planet.

The average temperature of Mars is a freezing -60 degrees C, but this plunges to -125 degrees C during winter at the poles (the coldest temperature ever recorded on Earth was -89.2 degrees C in Antarctica 1983). Although there is plenty of water on Mars, it is frozen solid.

Clearly, Mars is not a hospitable place. Is it possible that we could settle there? So far, human colonies on Mars remain in the realm of science fiction, but missions like the one launched this year will help us understand more about this intriguing world.

Louisa Watson

What is the Milky Way?

Most of us have heard of the Milky Way – the galaxy of stars in which our planet resides. But what exactly is a galaxy? And how did the Milky Way get its name?

A galaxy is a collection of stars, gas and dust that is bound together by gravity. None of this was known to our distant ancestors, of course; all they saw was a band of cloudy-looking stars stretching across the night sky. The Romans named our galaxy via lacteal (‘road of milk’) because it resembled a milky patch, while to the Ancient Greeks it was the galaxias kyklos (‘milky circle’).

The Ancient Greek philosopher Aristotle speculated that the Milky Way was created by interactions between the terrestrial and celestial spheres. About 1,800 years later, Galileo showed that it was a great group of stars, planets and other matter.

We now know that the Milky Way is vast, containing at least 100 billion stars. Imagine how many planets must be orbiting those alien suns! Light takes about 8 minutes to reach Planet Earth from the Sun, but it takes 100,000 years to cross from one end of the galaxy to the other.

The Milky Way is shaped like a whirlpool that rotates once every 200 million years. Its oldest stars are 13.4 billion years old – almost as old as the universe itself.  Our own Sun is a mere 4.5 billion years old and lies about 27,000 light-years away from the Galactic Core, which contains a super-massive black hole called Sagittarius A*.

If you find the size of our galaxy overwhelming, you’ll be astounded to learn that it’s just one of many.  The Milky Way is part of a cluster of 40 galaxies called the ‘Local Group’, which also includes Andromeda.  This itself is part of a super-cluster called Laniakea (Hawaiian for ‘immeasurable heaven’), which is 520 million light years across and contains 100 million billion stars!

There is more to the universe than our ancestors could ever have conceived. As we gaze at the night sky, we could feel daunted by our own insignificance, or we could marvel that we are part of something far greater than we can imagine.

Louisa Watson

Understanding Thunder and Lightning

From our earliest history to the present day, humans have experienced the flash of lightning and the crack of thunder as awesome natural forces.

There are countless legends explaining thunder and lightning – the Romans thought that thunder-bolts were the weapons of the god Jupiter while in Native American myth thunder is created by the thunderbird. In Medieval Europe, people believed that it was possible to avert lightning by ringing church bells.

There are also plenty of modern myths, the most famous being that ‘lightning never strikes twice’. This is clearly untrue, as the Empire State Building is hit about 20-25 times a year.

So what is lightning? The Ancient Greeks had several theories. Empedocles speculated that it was caused by sun-rays colliding with clouds. Aristotle thought that clouds emitted a ‘dry exhalation’ which burned and clashed with other clouds.

Many more ideas were put forward down the years, but it was the 18th-century scientist Benjamin Franklin who finally proved that lightning is electrical (according to the legend, he conducted a highly dangerous experiment involving a kite and an iron key).

We now know that lightning is a massive spark of static electricity which bridges the gap between the clouds and the land. Its heat expands the surrounding air, creating a compression wave which breaks the sound barrier and produces thunder.

Lightning is usually associated with rain-storms but it also occurs during blizzards, in the smoke which rises from forest fires, around volcanic clouds and nuclear fireballs, and even on other planets.

Lightning strikes the ground at 90,000 miles per second and is three times hotter than the surface of the sun. While each flash is approximately three miles long, it is only about a centimetre wide. At this very moment, about 2000 thunderstorms are occurring around the world, producing 6000 lightning-bolts a minute.

The lethal power of lightning must not be underestimated. On average, more people are killed by lightning in the USA every year than by hurricanes and tornadoes. While nine out of ten people do survive being hit, nearly 25% suffer long-term trauma. Some unfortunate people are hit more than once. The current record holder is Roy C. Sullivan, who was struck by lightning seven times.

The ‘Worst Lighting Strike Death Toll’ recorded in the Guinness Book of World Records occurred in 1963, when an airplane was hit on route from Baltimore to Philadelphia. The plane crashed, killing all 81 passengers.

When a thunder-storm approaches, the safest thing to do is take shelter in a building. As the National Lightning Safety Institute (NLSI) explains, if the space between the flash of lightning and the sound of thunder is thirty seconds or less, ‘the threat is imminent and the next strike may be at your location’.

The idea that you should seek cover beneath the branches of a tree is a dangerous myth – 18% of lightning victims are killed while standing under trees. Most people are hit either before or after the main downpour, which is why you should not leave cover until half-an-hour has passed since the last lightning-strike.

For more information, look up the NLSI’s Personal Lightning Safety Tips at

Louisa Watson