The First Images Of Pluto Sent Back To Earth

Pluto

Alan Stern, project leader It was not until this year after the New Horizons space probe swept over Pluto and on into deep space that we realised what a wonderful world we had uncovered. It was then that we got the first images back from the probe on our screens – and they were spectacular.


We could see Pluto had a blue atmosphere, a complex system of moons, and a smooth ice plain the size of Texas. The control room went wild. There were hugs and smiles and people spiking their arms in the air. I’m sure I used a lot of four-letter words and none of them were Nasa. We had not just made this historic journey across the solar system, but we had found that Pluto was, scientifically, beyond our wildest dreams.

We expected to find a complicated, icy outer world, of course. But what our brief encounter revealed was a world that was something between Earth and Mars – but at the outer edge of the solar system, 3bn miles away. We could see signs of active geology. The ice plain, Sputnik Plenum, has either been created in the very recent past or is continually being renewed. We can also see very old terrains and some intermediately aged terrains. So it is clear it has been geologically alive throughout its entire 4.5bn-year history. It should have cooled off by now, but it hasn’t. It is a puzzle of gargantuan proportions for planetary geophysics.

And that is why I believe we have to go back. We need to send an orbiter or a lander to Pluto next time. It took 26 years to plan, build, launch and track New Horizons, but I still want to be part of the team that goes back to Pluto. It is such a wonderful little world – the solar system’s last important outpost.