On November 12 2014, scientists from the European Space Agency will attempt to make a soft landing on a moving comet. If successful, it will be one of the most extraordinary achievements in space history and could answer important questions about the origins of life on earth. Here is everything you need to know about the mission.
What is the Rosetta mission?
Rosetta is a ground-breaking £1 billion mission to chase, orbit, and land on a comet.
The comet that has been chosen is 67P/Churyumov-Gerasimenko, which is in the Jupiter family of comets (comets with periods of less than 20 years)
The mission was first considered in the late 1970s but was not finally approved by the European Space Agency in 1993.
The original mission target had been comet 46P/Wirtanen, but it was changed to 67P/Churyumov-Gerasimenko when it was clear that the launch would take place in 2004.
The Rosetta spacecraft was launched from was launched from Kourou in French Guiana on board an Ariane rocket on 2 March 2004 and has been travelling ever since.
The comet is currently hurtling through space at 24,600 miles per hour and its nucleus is only 2.5 miles wide. Scientists compare the task to a fly trying to land on a speeding bullet.
Why is it called Rosetta?
Rosetta takes its name from the Rosetta Stone, a piece of black basalt incised with the same priestly decree concerning Ptolemy V, in three scripts, Egyptian Hieroglyphs, Egyptian Demotic and Greek.
The great significance of the Stone is that it provided the key to deciphering Egyptian hieroglyphs. Scientists hope that the Rosetta mission will unlock the mysteries of how the Solar System evolved.
The Rosetta Stone is currently housed in the British Museum in London.
Why has it taken 10 years?
The comet is moving far faster than speeds which could ever be achieved by a space ship leaving Earth. So the craft has spent the time since, using the gravitational pull of the Earth and Mars to act as a sling shot and allow it to pick up acceleration.
When it reached the crucial speed in July 2011 the spacecraft was put into deep-space hibernation for the coldest, most distant leg of the journey as it travelled some 497 million miles from the Sun, close to the orbit of Jupiter as the comet headed into outer Solar System.
Scientists extended its solar arms to catch the Sun’s rays and placed in a slow spin to maintain stability. The only devices left running were its computer and several heaters.
In January the spacecraft was woken up by an internal alarm clock when it was within 214 million miles of the Sun. It finally reached the come on August 6 2014.
Why land on a comet?
Comets are the primitive building blocks of the Solar System, left over from a planet-building time when our Sun was just a disc of spinning disc of dust and gas.
Made of ice, dust and small rocky particles, it is likely they delivered the first water to Earth and may have even seeded the planet with the building blocks for life.
Cometary dust brought back to Earth by NASA’s stardust mission contained glycine, an amino acid that is a basic building block of life.
What is the comet like?
Comet 67P/Churyumov-Gerasimenko is a large, dirty snowball, around 4.4km in diameter, whose orbit around the Sun takes 6.6 years. This makes it a short-period comet.
Images taken suggested that the comet was emitting water vapour into space at about 300 millilitres per second.
Meanwhile, the Visible and Infrared Thermal Imaging Spectrometer, VIRTIS, measured the comet's average temperature to be about -70ºC, indicating that the surface is predominantly dark and dusty rather than clean and icy.
When the craft was 12 000 km away images began to reveal that the nucleus comprises two distinct segments joined by a 'neck', giving it a duck-like appearance.
Comet 67P/Churyumov-Gerasimenko is so small that its gravitational pull is several hundred thousand times weaker than on Earth. For this reason, the Rosetta lander will touch down at no more than a walking pace. It will need a harpoon to safely anchor it to the comet’s surface and prevent it from bouncing back into space.
67P/Churyumov-Gerasimenko is named after its discoverers, Klim Churyumov and Svetlana Gerasimenko, astronomers from Kiev who “spotted” the comet for the first time in 1969 on a photographic plate. The 'P' identifies short-period comets with a well-established orbit around the Sun and that take less than 200 years to complete a solar revolution. The number 67 refers to Churyumov-Gerasimenko's position in the list of catalogued periodic comets. The most famous, Halley, is designated 1P.
Where will 67P/Churyumov-Gerasimenko be at the time of the rendezvous?
Rosetta will meet 67P/Churyumov-Gerasimenko when it is still in the cold regions of the Solar System at over 600 million kilometres from the Sun, when the comet and Rosetta are on their return journey back into the inner Solar System.
Will the Rosetta spaceship land on the comet itself?
No, Rosetta is carrying a small landing module called Philae, which is around 35 cubic feet in size.
It is named after an island on the river Nile, where an obelisk was found there containing an inscription which played an important role in deciphering the hieroglyphics on the Rosetta stone.
The lander will fire a harpoon and pull itself onto the comet. Once attached, it will send back a panorama of its surroundings and high-resolution pictures of the surface and will perform analysis of the composition of the ices and organic material.
A drill will take samples from 8-11 inches below the surface, feeding them to Philae’s laboratory for analysis.
Philae's landing site, currently known as ‘Site J’ is located on the smaller of the comet's two 'lobes.’
What will the Rosetta spacecraft do while Philae is on the comet?
Rosetta will stay alongside the comet, around 10km from the surface.
Instruments on board will analyse the gases of the tail; probe the comets interior; measure dust grains and study its atmosphere and gravity.
The comet will reach its closest distance to the Sun on 13 August 2015 at about 115 million miles, roughly between the orbits of Earth and Mars. Even if the lander is still on the comet by then its instruments will have been rendered useless due to the heat of the Sun.
Rosetta follow the comet throughout the remainder of 2015, as it heads away from the Sun and activity begins to subside.
Could activity on the comet's surface damage or destroy the lander?
Survival of the lander depends on a number of factors, such as power supply, temperature, or surface activity on the comet. At some stage the lander will probably become too cold and its solar arrays will no longer provide enough energy to continue operation.
What is the Rosetta mission?
Rosetta is a ground-breaking £1 billion mission to chase, orbit, and land on a comet.
The comet that has been chosen is 67P/Churyumov-Gerasimenko, which is in the Jupiter family of comets (comets with periods of less than 20 years)
The mission was first considered in the late 1970s but was not finally approved by the European Space Agency in 1993.
The original mission target had been comet 46P/Wirtanen, but it was changed to 67P/Churyumov-Gerasimenko when it was clear that the launch would take place in 2004.
The Rosetta spacecraft was launched from was launched from Kourou in French Guiana on board an Ariane rocket on 2 March 2004 and has been travelling ever since.
The comet is currently hurtling through space at 24,600 miles per hour and its nucleus is only 2.5 miles wide. Scientists compare the task to a fly trying to land on a speeding bullet.
Why is it called Rosetta?
Rosetta takes its name from the Rosetta Stone, a piece of black basalt incised with the same priestly decree concerning Ptolemy V, in three scripts, Egyptian Hieroglyphs, Egyptian Demotic and Greek.
The great significance of the Stone is that it provided the key to deciphering Egyptian hieroglyphs. Scientists hope that the Rosetta mission will unlock the mysteries of how the Solar System evolved.
The Rosetta Stone is currently housed in the British Museum in London.
Why has it taken 10 years?
The comet is moving far faster than speeds which could ever be achieved by a space ship leaving Earth. So the craft has spent the time since, using the gravitational pull of the Earth and Mars to act as a sling shot and allow it to pick up acceleration.
When it reached the crucial speed in July 2011 the spacecraft was put into deep-space hibernation for the coldest, most distant leg of the journey as it travelled some 497 million miles from the Sun, close to the orbit of Jupiter as the comet headed into outer Solar System.
Scientists extended its solar arms to catch the Sun’s rays and placed in a slow spin to maintain stability. The only devices left running were its computer and several heaters.
In January the spacecraft was woken up by an internal alarm clock when it was within 214 million miles of the Sun. It finally reached the come on August 6 2014.
Why land on a comet?
Comets are the primitive building blocks of the Solar System, left over from a planet-building time when our Sun was just a disc of spinning disc of dust and gas.
Made of ice, dust and small rocky particles, it is likely they delivered the first water to Earth and may have even seeded the planet with the building blocks for life.
Cometary dust brought back to Earth by NASA’s stardust mission contained glycine, an amino acid that is a basic building block of life.
What is the comet like?
Comet 67P/Churyumov-Gerasimenko is a large, dirty snowball, around 4.4km in diameter, whose orbit around the Sun takes 6.6 years. This makes it a short-period comet.
Images taken suggested that the comet was emitting water vapour into space at about 300 millilitres per second.
Meanwhile, the Visible and Infrared Thermal Imaging Spectrometer, VIRTIS, measured the comet's average temperature to be about -70ºC, indicating that the surface is predominantly dark and dusty rather than clean and icy.
When the craft was 12 000 km away images began to reveal that the nucleus comprises two distinct segments joined by a 'neck', giving it a duck-like appearance.
Comet 67P/Churyumov-Gerasimenko is so small that its gravitational pull is several hundred thousand times weaker than on Earth. For this reason, the Rosetta lander will touch down at no more than a walking pace. It will need a harpoon to safely anchor it to the comet’s surface and prevent it from bouncing back into space.
67P/Churyumov-Gerasimenko is named after its discoverers, Klim Churyumov and Svetlana Gerasimenko, astronomers from Kiev who “spotted” the comet for the first time in 1969 on a photographic plate. The 'P' identifies short-period comets with a well-established orbit around the Sun and that take less than 200 years to complete a solar revolution. The number 67 refers to Churyumov-Gerasimenko's position in the list of catalogued periodic comets. The most famous, Halley, is designated 1P.
Where will 67P/Churyumov-Gerasimenko be at the time of the rendezvous?
Rosetta will meet 67P/Churyumov-Gerasimenko when it is still in the cold regions of the Solar System at over 600 million kilometres from the Sun, when the comet and Rosetta are on their return journey back into the inner Solar System.
Will the Rosetta spaceship land on the comet itself?
No, Rosetta is carrying a small landing module called Philae, which is around 35 cubic feet in size.
It is named after an island on the river Nile, where an obelisk was found there containing an inscription which played an important role in deciphering the hieroglyphics on the Rosetta stone.
The lander will fire a harpoon and pull itself onto the comet. Once attached, it will send back a panorama of its surroundings and high-resolution pictures of the surface and will perform analysis of the composition of the ices and organic material.
A drill will take samples from 8-11 inches below the surface, feeding them to Philae’s laboratory for analysis.
Philae's landing site, currently known as ‘Site J’ is located on the smaller of the comet's two 'lobes.’
What will the Rosetta spacecraft do while Philae is on the comet?
Rosetta will stay alongside the comet, around 10km from the surface.
Instruments on board will analyse the gases of the tail; probe the comets interior; measure dust grains and study its atmosphere and gravity.
The comet will reach its closest distance to the Sun on 13 August 2015 at about 115 million miles, roughly between the orbits of Earth and Mars. Even if the lander is still on the comet by then its instruments will have been rendered useless due to the heat of the Sun.
Rosetta follow the comet throughout the remainder of 2015, as it heads away from the Sun and activity begins to subside.
Could activity on the comet's surface damage or destroy the lander?
Survival of the lander depends on a number of factors, such as power supply, temperature, or surface activity on the comet. At some stage the lander will probably become too cold and its solar arrays will no longer provide enough energy to continue operation.
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