Martina Aghopian sheds light on NASA’s first ever mission to Pluto
As an astrophysicist-to-be, I had vaguely heard of the New Horizons mission but had shamefully never read up on the details. However, on the 28th November I attended a New Scientist Live event where several astrophysicists gave lectures on the “Frontiers of Astronomy”. The day was filled with interesting talks, but Alan Stern’s was by far the star of the show. Alan Stern is the principal investigator (the leader) of New Horizons. New Horizons is the spacecraft that finally explored Pluto. Probes and/or satellites have visited all the planets in our Solar System but our favourite dwarf planet was the last to be explored. In the coffee break that followed my friend Paula and I managed to nab him just outside the auditorium and get a picture with him!
Fun fact: the International Astronomical Union (IAU) dubbed Pluto a dwarf planet in 2006 when they defined what a planet was. It was the third requirement that they imposed in their definition of a planet – a planet must have a cleared orbit – which Pluto failed at. For a planet to clear its orbit it must have enough mass, and therefore enough gravity, to force other large bodies out of its orbit and Pluto supposedly fails at this. However, does Pluto really entirely fail to qualify as a planet? Even if Pluto had the same mass as the Earth it still wouldn’t be heavy enough to have a cleared orbit. This is affected by the fact that Pluto has more area to clear than all the planets’ orbital areas put together! Also, “exoplanets” (planets not orbiting the Sun) aren’t even planets either by definition as they orbit their own parent star and not the Sun as specified in the definition. Astronomy is more confusing than one would first think, isn’t it?
Little Bumps in the Cosmic Road
There were several hurdles that the New Horizons team overcame – one of which was getting 42 states to sign off their approval for the launch. The probe is powered by plutonium and so needed approval to be fired up into the atmosphere. The Los Alamos laboratory, responsible for producing the plutonium, shut twice: first for six months and then after 3 months of being open, closed again. Thankfully, they produced the required amount of plutonium just in time!
Another issue was getting the spacecraft built and launched on time (January 19th 2006) for the only gravitational boost by Jupiter left in the 2000s. This boost allowed the probe to reach Pluto quicker. All of these deadlines were met in record breaking time despite many people expressing their doubts over the success of the mission. As Taylor Swift wisely sang: the haters gonna hate, hate, hate, hate, hate. The team, however, just shook it off!
The biggest ‘shake off’ happened ten days before the probe was due to fly by Pluto when the control room lost contact with the probe. The probe had been sent a list of commands to execute but it was overloaded with information and had to reboot. Naturally, this was a tense time for the entire New Horizons crew but they thankfully got back in touch with the spacecraft and it arrived 91 seconds early for the flyby!
Success At Last
Although there were setbacks to begin with, the mission itself proved a success. Several different features of Pluto were observed and measured by the probe and all the data saved on site. One of the main ways that Stern cut the costs of the project was by lengthening the time it took for the probe to feedback all its measurements. Currently more than 75% of all the data is still on the probe and hasn’t been sent back, with the final transmission of data in July 2016. However, from the data collected there have been several new and exciting features observed on Pluto. Several of these features have never been observed elsewhere in the Solar System. It seems that we may have saved the best for last. Looking at those images, you’ll see unique blade-like structures; a volcano comparable to the largest one in our Solar System (on Mars) and several mountain ranges. Pluto is covered with a veneer of nitrogen ice that hides a water ice crust. The baby of the Solar System isn’t quite as simple as we expected!
New Horizons was truly aptly named. It really has broadened our horizons with all its record breaking. It went supersonic in 30 seconds – the fastest spacecraft to be launched. It went out in style, in a 70m tall rocket. Although it’s not all about size, this probe has major bragging rights. Finally, it contains some of the ashes of Clyde Tombaugh – the astronomer who discovered Pluto. This poetic journey has even ended with Stern retweeting my photo and me gaining two new followers – #OMG. If you’re in awe, investigate further; there’s plenty more about the discoveries online.
featured image credit:www.penny4nasa.org
Other image credits: Wikipedia