On the edge of our planetary system, the dwarf planet Pluto orbits the sun. Unlike its Earth-like neighbour Mars, Pluto is still an unknown world. That’s why the 15 July 2015 – the day on which U.S. space agency NASA’s New Horizons probe approached Pluto – is a milestone in international space research. Launched nine years ago from Cape Canaveral Air Force Station, New Horizons travelled nearly five billion kilometres. On 15 July at 1.50 p.m. Central European Time, the moment had come: New Horizons came relatively close to the dwarf planet Pluto – within 12,500 kilometres.
Two days for seven experiments
The NASA space probe is not only the first to make a fly-by of Pluto, it is also the fastest probe that ever travelled in space. New Horizons flew past Pluto at a breathtaking speed of over 50,000 kilometres per hour. The researchers didn’t have much time for scientific measurements. Only for about two days was the probe close enough to Pluto to collect measurements and images. In all, seven experiments were conducted.
Planetary exploration using radio waves
The person responsible for two of the experiments is Dr Martin Pätzold. The planetary researcher from the University of Cologne intends to use radio waves to study Pluto’s atmosphere and determine the dwarf planet’s surface temperature. The measured data will provide information on the gases that make up Pluto’s atmosphere and the substances present on the planet’s surface. “We also want to directly determine the individual masses and densities of Pluto and its moon Charon,” says Dr Martin Pätzold. Once the Mars researchers know the weight and size of the planet and its moon, it will enable them to draw conclusions about the creation and internal structure of the planetary bodies.
Huge distances, difficult communication
The day after the fly-by, NASA researchers were able to present the first pictures to the public. The images show vast icy plains on the surface of Pluto. Planetary researchers across the globe are thrilled at these initial findings of the New Horizons mission. Further spectacular discoveries are likely to follow soon – the research labs’ computers have not yet received all the images and measured data. Even when travelling at the speed of light, the radio signals that transmit the data from the probe take as long as four and a half hours to reach Earth. Dr Martin Pätzold will have to be patient for around another year until the last of the measured data arrives in Cologne.
The New Horizons space probe
New Horizons is a probe sent into space by U.S. space agency NASA. It was launched from Cape Canaveral (Florida) on 19 January 2006. It made a close fly-by of Pluto and its moon Charon on 14 July 2015. That was a historic event: for the first time, Pluto and Charon – five billion kilometres from Earth – could be observed from close proximity.www.dlr.de > The New Horizons space probe