Rosetta Probe Orbits Comet


After ten and a half years and over 6 billion km of travelling, the European Space Agency’s (ESA) Rosetta probe has finally rendezvoused with the comet 67P/Churyumov–Gerasimenko.  It is the first time a man-made object has come so close to a comet. In the next few months, ESA plans to send a lander down to the surface of the comet.

Rosetta was launched in March 2004. It passed the sun five times and flew by several planets and asteroids before reaching the comet. The probe will stay close to comet 67/P for the next one and a half years. It will examine its surface and give scientists more information on the structure of a comet than ever before.

When it finally made contact with comet 67/P Rosetta was on its way towards the sun, about 400 million miles away from Earth. At such a distance, radio signals take about 20 minutes to get to our planet.

Comet 67/P is 4 km long and 2.5 km wide. It has a weight of over 10 billion tonnes. However, the comet has such a low density that it could float on water. The surface is made up of rock and ice. The comet is on an elliptical course through our solar system and swings around the sun every 6 years. It rotates around its own axis every 12 hours.

The next task for mission scientists is to choose the best landing site  for Philae, Rosetta’s lander.  This may prove to be a difficult procedure because of the rocky surface of the comet. In addition, Philae must always have contact with Rosetta and be able to get enough sunlight to recharge its batteries. The lander has on-board instruments that can drill into the surface of the comet and carry out many scientific tasks.

The Rosetta mission is very important to the European Space Agency ESA. If it is successful scientists may get important   information on how our universe was formed.

Philae lander on the surface of comet 67P/Churyumov–Gerasimenko

Philae lander on the surface of comet 67P/Churyumov–Gerasimenko - DLR


Related Topics



  • axis = the line around which an object turns
  • billion = a thousand million
  • density = mass, thickness
  • distance = space from one object to another
  • drill = cut into
  • elliptical = oval, a curved shape with two longer sides
  • examine = to look at something very closely
  • float = drift without sinking
  • however = but
  • lander = an object that can make a soft landing
  • landing site = place to land
  • launch = start, take off
  • man-made = not natural; made by people
  • mission scientists = people who are in charge of controlling the spacecraft
  • on-board = on the probe
  • probe = spacecraft without people in it ; it is sent into space to collect information on the moon, sun or other planets
  • prove to be = here: will probably be
  • recharge = to get new energy into a battery
  • rendezvous =  meet, make contact with
  • rotate = go around
  • surface = the top part of an object
  • swing = move in a fast curve
  • task = job
  • weight = how heavy something is