Which space agency launched the Rosetta comet mission?
Quick answer
The European Space Agency (ESA) launched the Rosetta mission on March 2, 2004. After a 10-year journey, it reached comet 67P/Churyumov–Gerasimenko in August 2014, becoming the first spacecraft to orbit a comet. Its lander, Philae, made the first-ever landing on a comet’s surface in November 2014.
Key facts
- Agency
- European Space Agency (ESA)
- Launched
- March 2, 2004, on an Ariane 5 rocket
- Target
- Comet 67P/Churyumov–Gerasimenko
- Mission ended
- September 30, 2016
A ten-year chase
To match the speed of a comet, Rosetta needed help from planetary gravity. It swung past Earth three times and Mars once, picking up speed. It also flew past two asteroids, Šteins and Lutetia. For 31 months it was put into hibernation to save power, then woke up on schedule in January 2014.
The Philae landing
| Date | Event |
|---|---|
| November 12, 2014 | Philae separates and descends for about seven hours |
| Touchdown | Its harpoons fail to fire, and it bounces twice, about 1 km high |
| Final rest | Lands in a shadowy spot near a cliff |
| ~60 hours | Sends back data until its battery runs out |
| September 2016 | Rosetta finally photographs Philae wedged in a crack |
Despite the rough landing, Philae completed most of its planned science.
What Rosetta discovered
- Comet 67P is shaped like a rubber duck, two lobes joined by a neck.
- Its water has a different chemical signature from Earth’s oceans, suggesting comets like it didn’t supply most of Earth’s water.
- It detected organic molecules, including the amino acid glycine; see what amino acids are.
- It found free oxygen gas in the comet’s coma, a surprise.
A planned crash
As 67P moved away from the Sun, solar power faded. On September 30, 2016, controllers guided Rosetta into a slow, controlled descent onto the comet, collecting data until the end.
Why “Rosetta”?
The mission was named after the Rosetta Stone, which unlocked Egyptian hieroglyphs; see what the Rosetta Stone is. Scientists hoped it would reveal how the early solar system formed. Philae was named after an island in the Nile where an obelisk helped confirm the decipherment.
Comets come from the outer solar system; see what the Kuiper Belt is.
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