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That would’ve made an arresting headline, wouldn’t it? Well, guess what, Star Wars fans – it really happened. The imperial units involved weren’t stormtroopers, though; they were things like inches, feet, and pounds. It’s hard to believe, but the good folks at NASA lost the Mars Climate Observer (MCO) – a $300 million mission – in 1999 due to a failure to convert to metric units. Here’s what the Mishap Investigation Board (what a delightful understatement, by the way – to call such a screw-up a “mishap”) had to say:

The MCO MIB has determined that the root cause for the loss of the MCO
spacecraft was the failure to use metric units in the coding of a ground
software file, Small Forces, used in trajectory models. Specifically, thruster
performance data in English units instead of metric units was used in the
software application code titled SM_FORCES (small forces). A file called Angular
Momentum Desaturation (AMD) contained the output data from the
SM_FORCES software. The data in the AMD file was required to be in metric
units per existing software interface documentation, and the trajectory modelers
assumed the data was provided in metric units per the requirements.

Besides being a redeeming story that you can triumphantly relate to the old math teacher who castigated you for every careless mistake, this incident does also evoke some worrying thoughts. Yes, we all make mistakes, but most of us aren’t in a position to cause a spacecraft to careen out of orbit to crash into a planetary surface. A lot of scientists, though, have access to a lot of things that – well, are capable of creating quite a big bang. What if someone had screwed up the insertion of a satellite into geostationary orbit around the Earth, for instance?

I’m not the sort who likes to foment panic about the dangers of rapidly advancing technology, and I suppose we’ve been pretty lucky so far. The LHC did not create a black whole that swallowed up the Earth, the National Ignition Facility in California did not set the atmosphere ablaze, and no nuclear power plant has turned out to be nuclear bomb (although I suppose the government of Iran may want to change that). But it is interesting to note that as our knowledge expands, our inimitable sense of curiosity becomes ever more potentially dangerous. In Kurt Vonnegut’s novel Slaughterhouse Five, a race of extraterrestrials called Tralfamadorians cause the extinction of the universe while experimenting with new energy sources. I wonder if a similar fate awaits us.


The mission badge for the Spirit rover, featuring Marvin the Martian

This image was named "Self-portrait with rock'

Sunrise on Mars. This panoramic image was one of the first to be beamed back to Earth

The Red Planet really is pretty red

Spirit is dying. And, one might say, it’s about time, too. The intrepid little rover’s been exploring the Martian surface since January the 3rd, 2004. It shares the Red Planet’s surface with its twin, Opportunity; but since their landing sites were almost diametrically opposite one another, they probably don’t get into too many fights about who’s on whose side of the planet.

Spirit, which is about the size of a dune buggy, got stuck in a sand trap in May 2009, and since only four of its six wheels remained fully operational by then, it hasn’t been able to extricate itself yet. This leaves the rover in an extremely vulnerable situation, as it’s unable to orient its solar panels to take full advantage of the sun’s energy, or to allow the wind to brush dust off the panels’ surfaces. And now, with the onset of the harsh Martian winter, when even less of the sun’s energy reaches the planet’s surface, Spirit may run out of power completely.

It would be a sad end to what’s been a long and fruitful life of adventuring. Far longer than nearly anyone expected, as a matter of fact. When Spirit and Opportunity were launched, their expected lifetimes were only three months. They’ve both already outlived that estimate by a factor of around 24. They’ve survived paralyzing cold, blinding dust and long periods without sun, all of which occasionally left them silent and still, but only until conditions improved and they shook off the dust, stirred to life and puttered off to do more work.

Don’t you just wish all electronic appliances were that resilient?

The Hubble Space Telescope- like the more recently built Large Hadron Collider (LHC) – is one of those icons of scientific endeavour that captures the imagination of thousands all over the world. Soon after it was launched in 1990, it was discovered that the main mirror, despite having been constructed to within 10 nanometres of all specifications, was incapable of producing sharply defined images. It took an extraordinarily difficult servicing mission to correct the Hubble’s optical flaws; but in the end, it was a complete success.

After that first servicing mission in 1993, The Hubble went on to produce some of the finest and most captivating images of space ever seen. (“Pillars of Creation”, one of the most famous Hubble images, is included here.) The astonishing detail and the nuanced coloration of these images lend them an evocative beauty that often transcends a lack of understanding of their actual subject matter in a way that few other scientific images do.

However, it may come as a surprise to learn that much of the appeal of these images comes not from the telescope itself, but from the astronomers and image processing specialists who- in a sense- “photoshop” the images before releasing them to the public. That’s because the Hubble only sends images in black and white!

Astronomers have to make choices about composition, colour and contrast in order to bring out specific aspects of the data that the Hubble beams down to Earth. And while these decisions often have scientific meaning (just for e.g., hotter stars are usually blue-ish white, whereas cooler ones are redder), they are also occasionally made purely in order to enhance the visual appeal of the images.

For people who’ve never had access to the Hubble’s raw data, it might be hard to rein in a vague sense of disappointment over the fact that the universe may not be quite that pretty, after all; but, looked at another way, it’s a whole lot more mysterious…

Seen from 6 billion kilometres (3.7 billion miles), Earth appears as a tiny dot.

Seen from 6 billion kilometres (3.7 billion miles), Earth appears as a tiny dot.

“Pale Blue Dot” is a photograph of planet Earth taken in 1990 by the Voyager 1 space probe from a record distance (6 billion km), showing it against the vastness of space. Both the idea for taking the distant photo and the title came from scientist and astronomer Carl Sagan, who also wrote the 1994 book of the same name.

In a commencement address delivered May 11, 1996, Sagan related his thoughts on the deeper meaning of the photograph:

Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.

"Earthrise", taken on December 24, 1968.

"Earthrise", taken on December 24, 1968.

“Earthrise” is the name given to NASA image AS8-14-2383, taken by astronaut William Anders during the historic Apollo 8 mission, the first manned voyage to orbit the Moon. The photograph was taken from lunar orbit on December 24, 1968 with a Hasselblad camera.

The famous "Blue Marble" photograph

The famous "Blue Marble" photograph

The famous “Blue Marble” shot represents the first photograph in which Earth is in full view. The picture was taken on December 7, 1972, as the Apollo 17 crew left Earth’s orbit for the moon.