Archives for posts with tag: planets

Courtesy ESA

Last week, the White House announced that humans would aim to set foot on Mars by 2033, just sixteen years from now. As a longtime space lover, I found this news momentarily exciting, but then I paused. Is sixteen years in any way realistic? I think not.

Taking people to Mars – and back again – is a massive engineering problem, on a scale we have never before encountered. I believe it’s possible to do it, but if we try to rush it, it will end in calamity. It breaks down to a number of key problems:


Without sufficient protection, astronauts will be subjected to intense radiation from the sun and from cosmic rays for the entirely of their journey. It goes without saying that space is a hostile environment, but, given the absence of a strong magnetic field, so too is Mars. We have very little experience of the effects of long term radiation exposure on humans outside of Earth, so a huge effort is required to gain more knowledge before we go. Frequent trips to or around the Moon would help, but given the absence of any such journeys in the last 40 years, we are starting practically from zero.


A crew of people will need to be sheltered, protected, fed, oxygenated, medicated and kept warm for up to three years from start to finish. They will need to have all the equipment they need to do their jobs, plus replacements, if something goes wrong. This implies a support structure to be in place – around Mars, on the way to Mars, on the way back from Mars and on the surface of Mars itself – before the astronauts begin their journey. That’s a lot of work – much greater than anything encountered by the lunar astronauts. Of course a very large craft might be able to bring people and supplies along in one go, but getting all this out of Earth’s gravity well and into the International Space Station will be a challenge in its own right, not to mention landing so much of it on Mars.

Getting off the surface of Mars

Apart from the Moon, we have never attempted lifting equipment – not to mention people – from the surface of another planet. The Moon, with its weak gravity, is much more trivial a problem than Mars would be. Consider the problems here on Earth. We have yet to conquer routine space launches. They require months of preparation and testing with teams of engineers to execute. Costs per launch are still in the millions of dollars. And even then, things can go wrong: launches fail regularly or are scrubbed in the last few seconds. Now imagine having to do this on Mars, where a failure, no matter how small, might mean you are left on the planet for good. We need a lot of practice at this, on Mars, before we attempt to bring people along.

Leaving them there

Sure, we could forego return craft and find volunteers to go to Mars for good, but without any prior experience of living on Mars, my guess is that they would not survive there for long. We on Earth would be treated to a real-time Truman Show of suffering, sickness and eventual death. This would quickly wipe the shine off mankind’s’ great achievement.


Right now, we still don’t know if life exists on Mars. Even though it’s unlikely, given the harshness of the Martian environment, it cannot be completely ruled out. Small traces of methane have been detected that deserve proper investigation. If we put humans on Mars – or god forbid, leave human corpses there – we lose our chance to find alien life there forever. We will have contaminated Mars with our own DNA, making any subsequent reports of life there highly suspect. We have the opportunity to make a truly extraordinary discovery on Mars. We owe it to ourselves to search hard for Martian life before we put boots there.

Let’s take our time

I get the feeling that this sixteen year trip to Mars is a kind of prestige project for Trump, as opposed to a genuine mission of science and discovery. I would love for us to visit Mars one day, but I think sixteen years is far too soon. We have a lot of learning to do and a lot of infrastructure to build before we can proceed with a manned mission that has a reasonable likelihood of success. Perhaps I’m pessimistic, but I think that the first successful landing is less likely to be sixteen years from now, and more likely to be sixty.

In 1584, the philosopher Giordano Bruno speculated that the Universe might be full of planets just like our own. For daring leaps of the imagination such as this, the Church duly branded him a heretic, rewarding him with imprisonment and a fiery death at the stake.

Today, we went one step further to proving him right. At a press conference earlier today, astronomers announced the discovery of two planets the same size as the Earth. These are the smallest planets ever discovered outside our solar system and the first definitive proof that worlds on a similar scale as our own exist.

The planets, Kepler 20-e and Kepler 20-f, are very close to their parent star, and therefore too hot to bear any real similarity to our home world. The news comes hot on the heels of the discovery of a planet in the “habitable zone” around a star, where it is possible for water to exist in liquid form. We are now hot on the trail of a planet that meets all the basic criteria for supporting life.

The discovery comes via Kepler: a space telescope that is surveying thousands of stars in a small area of the sky, roughly in the region of the Summer Triangle. It records the light emitted from each of the stars over time, playing close attention to any slight dips in brightness. These dips may indicate a planet moving in front of the star and momentarily blocking its light. Kepler’s systematic approach has revolutionised the science of planet hunting. To date, with just over a year’s data processed, it has found over 1,200 candidate planets.

It is surely only a short time now before a small Earthlike planet is discovered that is just the right distance from it’s parent star to support life. Who knows what may be discovered in the future about these small, watery worlds? We live in hope.

It’s beautiful

If you go out on a dark moonless night, you will immediately know what I mean. The Milky Way, stretching its jagged course across the heavens, is quite a sight to behold. The constellations, particularly the winter constellations, have an elegance and familiarity to them. The Moon is also an appealing object, with its ever changing phases and frequent conjunctions with other planets in the sky. Through a small telescope, planetary disks, galaxies, nebulae and open clusters come into view, often startling in their majesty.

Of course, the beauty of the universe is not limited to what is immediately visible to our eyes. Deep space objects, seen through the largest of telescopes, are candidates for some of the most beautiful things ever seen by human eyes. Who could not fail to be impressed by the wonderful Hubble photos of the Crab and Eagle nebulas, or the views of the outer planets and moons from space probes such as Voyager and Cassini? To see for yourself, each day NASA publishes it’s Astronomy Picture of the Day. Few images ever fail to impress.

It’s extreme.

Nothing can be taken for granted about space. Most of it is unimaginably cold, interspersed occasionally by blisteringly hot stars with coronal temperatures of millions of degrees. Almost everything is racing around at breakneck speed: barreling through space at velocities of hundreds or thousands of kilometers a second relative to us. That’s enough to cause quite an impact if we were to get in their way. All around us catastrophic convulsions are taking place, with vast explosions and unconscionably high energies. This is a Universe of supernovas, neutron stars, magnetars, pulsars and Gamma Ray Bursts – beams of high energy radiation that would eliminate all life on our planet in an instant were our Earth unfortunate enough to stray too close. Black holes exist that can compress the mass of whole stars into volumes a few kilometers wide, creating gravitational fields that nothing, not even light itself, can escape from.

This is the stuff of childhood fantasies. Superpowers. Forcefields. Instantaneous death. The destruction of worlds. It is no wonder that space features so prominently in the minds of the young.

It ignites our curiosity.

Astronomy confronts us with some of the biggest and most challenging problems about the nature of ourselves and the fabric of reality. As a science, it has lead the way in overturning ancient notions of how nature should behave. At one time we believed ourselves to be at the centre of the Universe, with all objects, including the Sun, revolving around the Earth. Astronomers through the ages slowly revealed a different truth. Our star and our home planet are among countless billions in a very ancient Universe. Everything we do ultimately only affects an infinitesimally small piece of real-estate in the cosmos. This discovery, while deeply humbling, is enlightening. It tells us that we will never know everything. Our quest for knowledge is unlimited. We are ants in a cathedral, and what a cathedral it is.

The study of the stars and planets has pushed out the frontiers of knowledge in every direction. It’s contribution to science and mathematics cannot be underestimated. Without astronomy, the modern world as we know it would not exist. Astronomy continues to confound us and guide us right to this day. Gigantic accelerators are busy smashing sub-atomic particles into smithereens to gain greater insights into the nature of matter because objects in space do not always behave the way our current scientific models expect them to. Astronomy has revolutionised our understanding of nature and it will continue to do so.

It tells us about our past.

When you look into space, at any star you care to mention, you are looking into history. You are not seeing the star as it is now, but as it was when the photons of light left its photosphere many years ago. If you can find the Andromeda Galaxy in the sky, you are getting a picture of how it looked two million years ago, long before humans ever roamed our planet. The largest telescopes can see back billions of years ago, to galaxies in their infancy, still in the process of being formed.

History is about ourselves, how we got here, why things are how they are. Astronomy opens history even further by explaining the origins of our planet, our sun, our galaxy – even providing insights into our Universe and how it all started some 13 odd billion years ago.

Astronomy is fascinating even when applied to our own modest human story. We have had an intense relationship with the stars and planets for thousands of years. It guided the ancient cycles of sowing and harvesting. It provided the raw material for belief systems, rituals and religions. It contributed to our language. It assisted with navigation and discovery. In living memory, we have witnessed men walking on the Moon and robot probes being flung out of the solar system – events likely to be celebrated for millennia to come. Our relationship with the stars has shaped the culture of today.

It’s our future.

Astronomy is important to our future, from the short term to the distant long term. Over the coming decades, private companies will take over much of the heavy lifting formerly associated with government agencies such as NASA and ESA. This will create new jobs and new wealth. Bigger telescopes and better equipment will provide insights into reality that will stretch our technological capabilities. Over the coming centuries perhaps we will explore and colonise deep space for ourselves, using technologies yet undreamt of. In the end, billions of years from now, our sun will expand, frying everything on this planet before diminishing in size itself, its fuel spent, its job done.

Perhaps there is a large asteroid or comet out there in space with our name on it. Perhaps our planet will eventually turn against us, forcing us to find a new home. Perhaps we will find a way to cross the enormous gulfs separating us from other stars in our galaxy. All of these possibilities lead us to the conclusion that the stars will feature prominently in the future of the human race.

Astronomy is available to all, from the small child with his toy rocketship, to the octogenarian peering through her telescope at a crater on the Moon. Few endeavours are so wide in scope, so rich in detail, or so marvelous in implication. I invite you to join in.

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