ON TUESDAY LAST, Mars was ‘in opposition’. This is a fancy astronomical term that means it was located directly opposite to the sun in the sky. At this point it was at its most ‘fully lit’, like a full moon, meaning that it appeared very bright in the evening sky. However, when it comes to things like planets, everything happens very slowly, and Mars is still very bright. So if you didn’t get to see the Red Planet on Tuesday, don’t worry, as it’s going to stay easy to spot for a good while yet!
Being in opposition to the sun, Mars rises in the east just as the sun sets in the west at around 8pm or so, but as it’s so close to the horizon at that time, and because the sky is still quite bright, you’re better off waiting for a couple of hours until later on in the night to see it. At about 10:30pm, Mars is located directly south-east, hovering over the horizon. As you probably know, the Red Planet got its nickname from its colour, and you will notice this colour as an orange tinge when you see it. Also, you don’t need binoculars or a telescope to see Mars: it’s very bright – brighter than surrounding stars – so it should be easy to spot.
Moving among the stars
Mars has always fascinated people, and has been observed for thousands of years as being different to the other stars in the sky. The stars always stay in the same place with respect to each other, whereas ancient astronomers noticed how it ‘wandered’ through the sky, moving differently to the stars. Some of the planets – particularly the ones beyond Earth’s orbit – move in strange ways as the weeks and months go by. This is because both they and the Earth are in motion as they orbit around the sun, so as time goes on our viewpoint changes, meaning that the planet we’re observing moves around among the stars.
By the mid-1800s, telescopes had advanced enough that astronomers were in a position to finally see some detail on the surface of Mars. That said, it was still quite tricky to make out a good level of detail; even modern amateur telescopes would be able to make out more surface detail on the planet. In the late 1800s, observations by Giovanni Schiaparelli - where he spotted “canals” – gave rise to the notion that there may be life on Mars. Over the following decades, astronomers noted seasonal changes on the planet, such as the polar ice caps shrinking and growing, and large dark patches forming during the Martian summer. Needless to say, this captured the imaginations of lots of people, as it brought the idea of extraterrestrial civilisations into a possible reality.
Life on Mars?
The inventor Nikola Tesla was investigating radio waves in our atmosphere at one point, and heard some strange signals. He became convinced that, even though he couldn’t make sense of the signals, they were communications coming from an alien race on Mars. The novel by H.G. Wells, The War of the Worlds, was also inspired by the notion of intelligent life on Mars.
The alien fantasy was shattered in the 1960s, however, when humans finally sent the Mariner probes to Mars, making people realise that Mars was cold and lifeless, probably not capable of supporting life.
More recently, scientists have started to look at the possibility that Mars harbours – or may have harboured – life, even of a microbial variety. We know that Mars was once a watery planet, as we have seen lots of dried-up rivers, lakes, and seas. As you read this, the Curiosity and Opportunity rovers are exploring the surface of the Red Planet, searching for evidence of ancient life. Future missions are being planned, too, where craft will be sent to drill underneath the planet’s surface, and to analyse the gas in its atmosphere, for evidence of life. Within the next few decades, humans are expected to travel to Mars, with the European Space Agency aiming for a mission between 2030 and 2035, and NASA aiming for 2037.
Voyages to all of the planets will eventually become routine
But how many of these missions will make it to Mars? Interplanetary voyages to Mars have experienced a very high failure rate: out of 51 missions, only 21 have been fully successful, and people started to call this the “Martian Curse”. One notable (and embarrassing) failure was with the Mars Climate Orbiter: as the craft approached Mars, computers on Earth worked out numbers for the thrusters to get it into orbit. However, the numbers outputted were imperial units. The spacecraft expected metric units. As a result, it was off-course, and the mission came to an end when the Mars Climate Orbiter burned up in the Martian atmosphere.
Of course, missions to Mars are a significant technological feat. As we learn from our previous mistakes and develop better technology, voyages to all of the planets will eventually become routine.
And that is when we will set our sights on the stars.
Conor Farrell is an avid science enthusiast and studied physics with astronomy at Dublin City University. He has worked at Astronomy Ireland and Dunsink Observatory in the past, and loves to promote all things space-related to a wider audience. In his spare time he writes about science and current affairs, and can be followed on Twitter at @conorsthoughts.
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