On 15th of October 1997, NASA, along with the European Space Agency and the Italian Space Agency, launched a probe to explore the Saturn planet and its system. Cassini-Huygens was named after the two astronomers that created the probe: Christiaan Huygens, who built the orbiter and Giovanni Domenico Cassini, who built the atmospheric probe.
After eight years of space travel, on the 14th of January 2005, ESA’s Huygens left Cassini and landed on Titan, Saturn’s biggest moon.
The descent, which lasted for two hours and 27 minutes, created not just history – by being the first probe to land in the outer solar system. Spinning in the wrong way – anti-clockwise at a very decreased rate of 7.5 rotations per minute – the landing also created anxiety among the scientists. It happened for just 10 minutes, right at the beginning.
For the rest of the landing, Huygens behaved, but it was enough to incite the scientist to look for answers for 15 years, and today they finally have one for Huygens’s bad behavior. They called it the negative torque.
Scientists Solved The Mysterious Spin Of Huygens
What happened? Huygens was released from Cassini spinning. Its spin rate helped to maintain it stable for the three weeks coasting down to Titan. At the entrance in the moon’s atmosphere, two of the probe’s primary auxiliary – the Separation Subsystem and the Radar Altimeter antennae – produced an unforeseen torque opposite to that produced by the 36 angled vanes designed to control Huygens spinning.
As the vanes altered the gas flow around the descent module, it enhanced the amplitude of the torque until it exceeded the influence of the vanes.
Huygens came through the event and, along with Cassini, continued to make history by gathering highly important discoveries about Titan: evidence of past watery activity, signs of cryovolcanism, and, potentially, a large subsurface ocean.
It made measurements of its atmosphere and established that it contains methane, nitrogen, and tiny aerosols. It spotted strong east-west winds in the moon’s atmosphere – some of which rotated faster than the moon itself. And its 10 minutes of wondering are changing today’s spaceship craft.