Pluto flyby

After over 9 years of speeding through space New Horizons probe visited last of the original 9 planets – Pluto. Finally we were suppose to get clear images of Pluto and it’s surface. I asked our panel about how did they feel about the flyby and if they think that it was ok to demote Pluto from a planet status in 2006.
Andrew Rader (SpaceX engineer, MIT PhD, author)

Very exciting to round out the original list of planets. The visit doesn’t officially promote Pluto to planet but it was larger than anticipated, probably larger than Eris. This means that it might qualify for special status. Additionally, even planets like Jupiter and Earth don’t fully qualify for planet status because they haven’t cleared their orbits around the Sun of all other objects. Thus, Pluto’s status might be worth a revisit. Although there’s nothing terribly wrong with being a dwarf planet. Pluto is small, and being a dwarf puts it together with other interesting worlds like Ceres, which I find to be one of the most interesting in the solar system.

Brian Koberlein (astrophysicist and physics professor at Rochester Institute of Technology, author, podcaster, publisher)
I think it’s important to keep in mind that the flyby is just beginning. Yes, New Horizons is speeding away from Pluto now, but we’re only beginning to get the data back from the flyby. It will be months before we have a good idea of what the mission has gathered. So far, I think it was a great success. We now know that Pluto is an active world with geological activity. It has mountains for goodness sake! I’m sure the flyby will have much to tell us about this rich and complex world.

I think people blow the whole “Pluto’s a planet” thing out of proportion. The classification of what makes or doesn’t make a planet is an arbitrary line in the sand that we create. The revised definition was an easy line to draw because the 8 planets are very different from Ceres and Pluto which are significantly smaller. If there wasn’t the emotional attachment to Pluto no one would argue otherwise.
I think it’s important to keep in mind that no one has made Pluto less real, or special or unique. If Pluto is your favorite solar system body, it can still be your favorite. The only thing that has changed is that astronomers have moved Pluto from one arbitrary column to another.

Fraser Cain (publisher at, co-host of Astronomy Cast)

I feel a special kinship with the New Horizons spacecraft. It was one of the first stories I reported on when I started out in space journalism more than a decade ago, and I watched it all the way through the launch, and its flyby of Jupiter. I knew that our first look at Pluto would be nothing short of amazing; not just with the questions that New Horizons would answer, but the brand new mysteries that it would reveal. New Horizons didn’t disappoint. Nobody expected to see such a young surface on Pluto, with ice mountains! And then Charon turned out to be a completely different looking world with huge cracks and strange features on its surface. We’ll be riveted over the next 16 months as the data trickles in from New Horizons.
Was it a good decision to demote Pluto? I don’t really have an opinion either way. Eris is almost the same size as Pluto, so if Pluto gets to be a planet, shouldn’t Eris be one too? We’re never going back to 9 planets, so you just have to decide, do you want more planets or less? 8 planets or 12?

Robert Novella (co-founder and vice-president of New England Skeptical Society, co-host of Skeptics’ Guide to the Universe)

The flyby was incredibly exciting. Clearly one of the top science stories of the entire year. The fact that we made so many unexpected discoveries (it has extensive geology) and we now have new mysteries to solve is one of the hallmarks of good science.
That fact that New Horizons is exploring the uncharted “Third Zone” of our solar system is also one of those rare missions that will expand our fundamental knowledge by leaps and bounds.

I wasn’t greatly perturbed by the demotion of Pluto. The criteria for planet-hood is ultimately a subjective thing. The real benefit in my opinion was that we now have a more detailed description of what a planet is.

Pamela Gay (assistant research professor at Southern Illinois University, writer, co-host of Astronomy Cast)

The flyby was very much a success. Between New Horizon’s observations of Pluto and Charon and Dawn’s observations of Ceres, we’re getting a new understanding of just how active and how complicated the geology of tiny worlds can be. No one expected what we’re finding, and that means this is science worth doing: our understanding of the universe is being challenged by data that invalidates many of our prior theories. Data always wins and now we get to try again at defining the nature of small body geophysics.

As for Pluto being a planet or not being a planet; Pluto is the exact same icy world it was before. All that has changed is people are now getting rich by giving talks declaring it a Planet and Not a Planet. I don’t care about Pluto’s designation, but I admit to being upset that some people are getting paid for a single talk what the junior scientists studying Pluto earn in a year. People have a right to make a buck, but I had hoped this kind of petty drama-based income could be kept out of science. (I’m also angry that the junior scientist are working sleepless weeks and earning so little, but that’s a different problem.)

Leave a Reply