Wednesday, June 17, 2015

One Month Out: It's Beginning to Look a Lot Like Pluto


It is now less than a month until New Horizons encounters Pluto, and like a rock star, Pluto is everywhere in the media. Articles, videos, animations, and images are coming so fast that it feels nearly impossible to keep up with them all.


Let me know if there are any Pluto magazine covers I've missed!

Slowly, the small planet is beginning to give up its secrets. Images taken by New Horizons’ Long Range Reconnaissance Imager (LORRI) show Pluto’s surface to be one of high color contrast, with bright regions, dark regions, and intermediate regions. This matches our best Hubble images, which though blurry, show great a planet with a very contrasted surface.

Significantly, Pluto appears to have a polar cap! That makes it one of only three solar system planets to have polar caps—the other two being Earth and Mars.

Studies of the Pluto system’s four small moons indicate they have odd, tumbling orbits, caused by the fact that they orbit two bodies—Pluto and Charon. These dynamics affirm we are looking at a true binary planet system—the only one in our solar system.

Astronomers who study binary stars have been inspired by Pluto-Charon, thinking of it as an analogue to the systems they research, only much clo
 
The Pluto system has even been seen as an analogue of Jupiter and the Galilean moons. Three of those four moons, Io, Europa, and Ganymede, orbit Jupiter in the same resonance as that at which the small moons orbit Pluto-Charon, repeating the same cycle again and again.

Like Pluto’s small moons, all four Galilean moons never all line up at the same time. This configuration helps stabilize their orbits by minimizing the gravitational strengths between the satellites.

The sizes of Pluto’s four small satellites relative to Pluto are similar to the sizes of the Galilean moons relative to Jupiter. The key difference in the two systems is the Galilean moons orbit one object rather than two.

And this is only the beginning…

In early July, New Horizons will begin spectroscopy, which will identify the composition of Pluto’s surface. Then comes mapping of Pluto and Charon, study of atmospheric patterns, and measuring the solar wind, high energy particles, and dust particles in the environment around Pluto.

Every Tuesday until the flyby, members of the mission team are presenting updates on NASATV at http://www.nasa.gov/multimedia/nasatv/ . The updates air live at 11:30 AM EDT, then replay at 3:30 PM, 7:30 PM, 11:30 PM, and 7:30 AM the next day, all EDT.

Recordings of the updates are also posted on NASA’s YouTube channel at https://www.youtube.com/channel/UCLA_DiR1FfKNvjuUpBHmylQ .

I am covering the New Horizons mission for the website Spaceflight Insider, at http://www.spaceflightinsider.com . Dating back to August 2014, my articles on the mission can be found at http://www.spaceflightinsider.com/?s=Pluto .

From July 13-15, I will be at Johns Hopkins University Applied Physics Lab (JHUAPL) for events surrounding the flyby as a correspondent for Spaceflight Insider. Of course, I will also be posting on this blog.

Naturally, with so much attention on Pluto, the issue of its planet status is coming up a lot. The diehard supporters of the IAU decision are going on record stating how interesting Pluto will be, how much they love Pluto, how much they are looking forward to the flyby—but no matter what is learned, Pluto will never be a planet because it does not “clear its orbit.”

But many more are questioning just what “clearing its orbit” means. Looking at what is clearly a binary system, a primary object with a polar cap and one of the most complex, contrasty bodies in the solar system, they do not see something that is just one of many rocks or “dirty snowballs” among thousands in the Kuiper Belt.

They see a system that is unique and in some ways more like Earth than any other solar system planet.

Is Pluto’s status a separate issue from its science? That is a matter of opinion, but I say no. The science—not a tiny group of “experts”—will tell us what this object is. And those doing that science, obtaining this data for the first time in human history, are the ones who will write the textbooks about Pluto.

In 85 years, we’ve gone from a tiny dot to not just a world but a complex system.

When I go to JHUAPL next month, there will be a personal sadness I never could have anticipated. I had been rooting for the late Patsy Tombaugh to get her wish of living to see the flyby. She would have been 102. Sadly, she died in January 2012 at age 99.

But I never expected my dad to not make it to the flyby. He would have been 83 and was vibrant and healthy until an unknown illness that we suspect to be myeloma snuck up on him and took him from us on March 19 of this year.

Only a few days before he fell into a coma, he had asked me, “How’s Pluto?”
 
I want to imagine him watching the flyby along with the Tombaughs, Venetia Burney Phair (the little girl who named Pluto), and so many other Pluto huggers who have passed on in luminous forms, at one with the Force, much like Obi Wan Kenobi, Yoda, and Anakin Skywater appeared in the victory celebration at the end of Return of the Jedi.

May the Force be with New Horizons and with the entire Pluto system!

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