In 1799, a French army engineer stumbled across a chunk of dark grey rock in Egypt, used as part of the foundation of an old building. The engineer was working to improve defences of a fort in the Nile Delta, but one of the chunks of the building was covered in writing – in Ancient Egyptian hieroglyphs, in Demotic, and in Ancient Greek. It would be dubbed the Rosetta Stone, the first key found to deciphering the script that was used for thousands of years in Egypt.
The modern Rosetta, more than 200 years later, is now swinging into orbit around a comet.
Launched by the European Space Agency, the Rosetta is a spacecraft that has been silently putting itself into position for more than a decade. It has spent years at a time locked in stasis, sleeping away month after month to conserve energy while it looped through the Solar System to rendezvous with its target.
If all goes well, the Rosetta will soon deploy a lander that will make history – the first controlled landing on a comet.
The comet is not one of the more famous ones in the night sky, no Halley’s Comet or Hale-Bopp. It has the inelegant name of 67P/Churyumov–Gerasimenko, a designation number plus the names of its Soviet discoverers, who spotted it back in the 1960s.
We know remarkably little about comets. They come in from the outer edge of the solar system, balls of rock and ice and chemicals, they swing by the sun on wild elliptical orbits, spewing their bright tails. Then they vanish again, sometimes for decades, sometimes seemingly forever.
We’ve seen them slam into planets, most recently with the massive impact of Shoemaker-Levy 9, which drifted too close to Jupiter, was captured by the gas giant’s gravity, and eventually broke up and crashed.
A sizeable comet or asteroid slammed into the earth about 66 million years ago, smacking into what was then a shallow sea. The 10 kilometre space rock left a 150 km crater and very, very few dinosaurs.
Studying comets is to study the early history of the solar system, and to study objects from its outer reaches.
With the first images beamed back as the Rosetta swung around Chryumov–Gerasimenko, we are already finding out how much we didn’t know.
Early photos and reconstructions of the comet, taken from near earth, showed a sort of blobby, four-lobed shape, like a mushed diamond marshmallow from a box of Lucky Charms.
In truth, it looks like a mutated potato, with one large lump, a small spur, and a big lobe that sticks off like the head of a human femur.
We’re going to learn a lot from this mission, and it’s only costing us about a billion dollars.
Don’t worry, you’re not on the hook for anything in particular, as this mission was set up by the Europeans with a little cooperation from NASA. But if Canada had contributed, it would be worth it.
Every time there’s a new space mission, there’s a chorus of voices raised in online comment threads and letters to the editor: why aren’t we spending this money on Earth, on real problems?
To which the snarky answer is, why do you spend money and time watching movies and sporting events? Why not donate every extra dollar to charity and live on gruel?
We should support science for the same reasons that we support the arts and athletics. Learning for the sake of learning is one of the things that makes us human.
Rosetta may help us decode the only solar system we call home. We don’t know what we’ll learn, and that’s what’s so exciting about being alive right now.