Since the beginning of the Space Age, man has sent many manned and unmanned missions into space. Very powerful telescopes, built around the world, broaden our vision and understanding of the universe. Spacecraft, whether visiting other worlds or orbiting the Earth send us images and data collected from our outer atmosphere to the outer planets and beyond.
However, all this was only possible thanks to the incredibly rapid development of technology in recent years. Only then, could the essential resources for the construction of the current generation of spaceships be developed.
So, let us talk a little about some of the most important of space exploration’s tools and its greatest discoveries in this series, called Astronomy Tech.
In this first post, let’s get to know Cassini-Huygens a bit better. It is a joint mission between NASA, the European Space Agency (ESA) and the Italian Space Agency (ISA), which has uncovering the secrets of Saturn, including its rings and moons, as its primary objective.
An artist's impression of Cassini-Huygens Credit: NASA
On October 15th, 1997, the Cassini-Huygens spacecraft – composed of NASA’s Cassini orbiter and the ESA’s Huygens probe – was launched, beginning a long and complex seven-year journey, including gravitational slingshot manoeuvres around Venus, Earth and Jupiter. After arriving at its destination, the mother ship; Cassini, began its main objective exploring Saturn, whilst the Huygens probe was lunched and landed on Titan –Saturn’s largest moon and the second largest in the Solar System, after Jupiter’s moon Ganymede.
The spacecraft’s name was a tribute to the Italian Jean-Dominique Cassini (1625-1712) – discover of the Saturnine satellites Iapetus, Rhea, Tethys and Dione. In 1675 he discovered what is known today as the ‘Cassini Division’, the narrow gap separating Saturn’s A and B rings. Christiaan Huygens (1629-1695) was a Dutch scientist who first described Saturn’s rings and, in 1655 he discovered the moon Titan.
Cassini’s “senses”
The Cassini spacecraft has a set of 12 instruments on-board. Some of them work in similar ways to our own. However, the instruments on the Cassini spacecraft are much more advanced than our own.
Cassini can “see” in wavelengths of light that the human eye cannot. The instruments on the spacecraft can “feel” things about magnetic fields and tiny dust particles that no human hand could detect. This means that Cassini can, for example ‘see the temperature’ of the objects it observes.
The magnetic field and particle detectors take direct sensing measurements of the environment around the spacecraft. These instruments measure magnetic fields, mass, electrical charges and densities of atomic particles. They also measure the quantity and composition of dust particles, the saturation of plasma (electrically charged gases), and radio waves.
Exploring the Ringed Planet
The expected return to Saturn – which hadn’t been visited by any spacecraft since Voyager 2 left Saturn’s orbit in 1981, – happened in July 2004. Since then, Cassini has made great discoveries about the Saturnine System and taken some terrific pictures, like the one below.
An Eclipse of Saturn, with the Rings Visible Credit: Cassini/NASA
A few days after reaching Saturn, Cassini released the Huygens probe to land on Titan. On January 14, 2005, during its fall, six instruments analysed Titan’s atmosphere. According to the returned data, Titan has a nitrogen rich atmosphere. It also confirmed that Titan’s orange colour is due to the presence of hydrocarbons, formed when sunlight breaks down the abundant methane molecules within the atmosphere.
These results have given scientists a glimpse of what Earth might have been like before life evolved. They now believe Titan possesses many similarities to the Earth, including lakes, rivers, channels, dunes, rain, snow, clouds, mountains and possibly volcanoes.
Cassini’s mission
Isn’t over yet; every day, it sends us vast amounts of data back to astronomers allowing them to resolve and answer questions about Saturn and our own planet.
You can see more about Cassini on its official website. If you want to hear the news first hand, you can follow Cassini on Twitter.
