Something about a comet


Scientists at the European Space Agency (ESA) are analysing data sent back from a research vessel that landed on a comet on the other side of the solar system. Exciting, to say the least!

The ESA’s spacecraft is named “Rosetta” after the town in Egypt where the Rosetta Stone was found, which helped decipher the Egyptian hieroglyphic language. Rosetta has been flying next to a comet named 67P, which lies beyond the orbit of planet Neptune. The amazing thing is that the mission has been going on for the past 10 years. That’s how long it took Rosetta to travel the four billion miles from Earth to comet 67P.

Why are scientists so interested in studying a comet lying on the other side of our solar system? Comets, it turns out, can help us understand a great deal about the changes occurring in the cosmos. They provide clues about the Big Bang theory of the universe’s formation, an explosion of matter that started billions of years ago and that is still perceivable in the movement of the planets and stars that make up the cosmos.

Close-up photo of the comet sent by the lander Philae as it fell the 14 kilometres to the surface (photo: europeanspaceagency)

In addition, should the mission succeed in gathering the physical data from this landing, the chemical composition of the comet may reveal secrets about primitive life through the molecules it contains. Those molecules include trapped gases released as the comet nears the sun, ice, water and more complex chemical compounds found in living matter called “organic molecules”. This may give a hint about the question of life on another planet and a theory that life on earth could’ve landed from another planet through a comet.

Spacecraft Rosetta has been orbiting 67P for a year, studying changes that occur as it comes nearer to the sun. Changes in magnetic field and solar wind will also be recorded and may offer clues as to the sun’s ever-changing combustive chemistry. Rosetta is expected to send lots more information as it continues to orbit the comet until December 2015.

Designed to always face the sun, the 14-metre-long “wings” on either side of the spacecraft are actually solar panels for gathering energy (image: thewestsidestory)

After surveying the comet from afar, it is now time for a closer look. A lander robot called Philae (another reference to Egypt’s glorious past) was designed to go down to the comet’s surface. Phillae was ejected from the spacecraft at a precise moment so it could fall down 14 miles onto the surface of the comet, driven only by its low gravity. It carried probes and tools designed to send information to the spacecraft for transmission to earth. Scientists said the landing craft bounced twice and came to rest next to a cliff that blocked sunlight from its solar panels, shortening its active time on the comet.

According to the ESA, Philae successfully transmitted to Rosetta information on the composition of the comet before exhausting its energy reserves and ending contact. Things like the temperature, density of the core and the nature of the gases emitted all interest scientists.The lander had to collect the data fast: its period of activity was limited to 64 hours before it ran out of power.

Using mind-boggling technology, the lander and spacecraft communicate by radio waves; when they are across from each other they can probe the inside of the comet through radio waves to give a map of its core structure.

Technologically dazzling as it is, the project aims to uncover pieces of the puzzle that can help us better understand the nature of the universe around us. It has already accomplished much, beyond the scientists’ science fiction dreams.

Sources: National Geographic, European Space Agency and TIME websites