‘Little lander that could’ awakes on a comet
Six months ago, the Philae lander made a miraculous landing on the surface of a distant comet. Now, after six months of hibernation, it has awoken. Why do we find this story so inspiring?
Meet Philae the robot, a metal box no bigger than a washing machine who has achieved feats that many scientists thought impossible. Last year, after travelling 6 billion kilometres through space, it entered the orbit of a small, misshapen rock that was hurtling chaotically around the sun. Philae parted company with its spacecraft and, with no guidance from Earth, carried out a bumpy landing on the comet’s surface, inspiring the delight and astonishment of the world.
But the joy was not to last. Stuck in a crater and starved of sunlight to feed its solar panels, Philae’s primary power lasted 60 hours on the comet. Six months of radio silence ensued.
Then, this weekend, a message suddenly appeared on Philae’s Twitter account: ‘Hello Earth! Can you hear me?’ Scientists were jubilant once again. One worker at the European Space Agency (ESA), which ran the mission, described the moment she received the news while travelling to her mother’s house in a taxi: ‘I hugged the poor old taxi driver... I think he was a bit startled.’
Philae is part of an ambitious mission whose main protagonist is the Rosetta space probe. Since its launch in 2004, Rosetta has navigated the asteroid belt and catapulted around Mars. It flew closer to Jupiter than any craft before it and became the first spaceship to enter the orbit of a comet. But Philae’s landing was the mission’s climax, and the moment it captured the attention of the world.
Now that Philae is awake, scientists on Earth will instruct the rover to drill into the comet’s surface and analyse the rocks it finds. If its power lasts for long enough, it could give us rare and vital insights into the nature of the Solar System’s oldest and most primitive bodies.
The chemistry of comets might sound like an obscure area of interest, but Philae’s discoveries may shed light on matters closer to home. It is thought that comets played a major role in forming Earth’s oceans and atmosphere and even provided the chemical building blocks for life itself.
Comet up roses
There’s no doubt that Philae’s journey is an impressive technical achievement and an important moment for astronomy. But is that really why the rover has captured the world’s imagination? No, some say: it’s not the science that has captured our imagination, but the sentimental feel-good story of a ‘plucky’ spacecraft and its daring deeds.
But perhaps this intrepid spirit is exactly what science is all about. The Rosetta mission relied on a diverse team of people overcoming daunting technical challenges in ingenious and creative ways, all motivated by a simple thirst for knowledge. Philae inspires people, some say, because it is a symbol of humanity at its best.
- Why are so many people excited about Philae’s successful landing on the surface of a comet?
- Should governments invest more money in space exploration, or less?
- What should the European Space Agency’s next big mission explore? Come up with some ideas as a class and vote for the best one.
- Do some research and create a short fact file about comets — where they come from, what they are made of and their relationship to planet Earth.
Some People Say...
“Science is a way of thinking much more than it is a body of knowledge.”Carl Sagan
What do you think?
Q & A
- Space exploration is impressive and all, but what’s the point? Isn’t it all just gas and rocks?
- Actually, the gas and rocks are pretty rare. Mostly it’s a vast near-vacuum with a smattering of individual atoms. But its emptiness needn’t make it boring. Learning what’s out there can help us understand how the universe — including our own planet — came to be.
- So what might Philae discover on this comet?
- Comets are remnants of our solar system’s earliest days. Their chemical makeup has scarcely changed since the time when all the matter in the sun and its planets was a vast, formless nebula, so studying them may teach us what the solar system was like millions of years ago. Philae could also help confirm the theory that many of the elements crucial to life were brought to Earth by comets.
- Bumpy landing
- Philae was supposed to land in a spot more exposed to the sun. But because of the comet’s low gravity and the failure of the lander’s harpoons, it bounced twice before coming to rest.
- Solar panels
- Not only Philae but the spacecraft Rosetta were powered by energy from the sun. This technology could allow spacecraft to travel far greater distances.
- European Space Agency
- An international collaboration between 22 European states. Its budget is significantly smaller than NASA but about the same size as Russia’s space programme.
- The craft is named after an ancient stone which presents the same texts in three languages. It provided the key to translating hieroglyphics. The Philae obelisk played a similar role.
- Rosetta generated speed using the gravity of Earth, Mars and Jupiter like a slingshot, entering their orbits temporarily before flying out into space.
- Chemical building blocks
- Comets are thought to have brought organic compounds to Earth. Without these, life could never have developed on our planet. Philae has already found some evidence of this.