The Pluto Science Conference Day 1: New Horizons and the Kuiper Belt

Today was the first of a five-day Pluto Science Conference being held at the Johns Hopkins University Applied Physics Lab, the same site where the Great Planet Debate was held five years ago. I feel very lucky to be back here, in a town named Laurel in Maryland for five days of All Pluto, All the Time!

The conference is being held in anticipation of the New Horizons flyby of Pluto, now just five years away. Most though not all attendees are professional astronomers and/or members of the New Horizons team.

Day one focused on New Horizons itself, with separate presentations on each of the instruments on board the spacecraft. This comes only about a week after a successful nine-day rehearsal for the encounter held earlier this month.

We learned that New Horizons will be able to take images better than those taken by the Hubble Space Telescope starting in May 2015.

Dr. Alan Stern and several other speakers discussed the effort to get a mission to Pluto off the ground, an effort that goes back 20 years, conceived after mutual eclipses by Pluto and Charon of one another revealed that Pluto has an atmosphere.

“Pluto has received worldwide attention because it is a solar system body worthy of intense study,” Stern noted.

Dr. Tom Krimigis outlined the science objectives of New Horizons, divided into three groups: measurements required for the mission to be a success, known as group 1; highly desired measurements, group 2; and bonus/desired measurements, group 3.

Seven phases of the Pluto encounter were outlined. These include Approach 1, January 6-April 4, 2015; Approach 2, April 4-June 23, 2015; Approach 3, June 23-July 13, 2015; Near Encounter Period, July 13-15, 2015; Departure Phase 1, July 15-August 4, 2015; Departure Phase 2, August 5-October 22, 2015; and Departure Phase 2, October 22, 2015-January 1, 2016.

During the flyby, observations from Earth-based telescopes will be done to complement the data from the encounter. This means there will be two simultaneous studies of the same objects—one “in situ,” meaning at the site (Pluto), and the other from Earth.

While the most important data will be sent back first, it will take an entire year to downlink all the data from the flyby. Pluto will still be surprising us well into 2016.

The second part of the day focused on the context of the Kuiper Belt, including plans to fly by one or two small KBOs after Pluto. Because of fuel concerns, these KBOs must be in a narrow cone along the spacecraft's trajectory. Astronomers have been searching for such objects but have not yet chosen any specific ones although they expect to find two or three. This was also a goal of the citizen science Ice Hunters and Ice Investigators projects though both those projects have completed going through the data they had been given.

There was much discussion of the different parts of the Kuiper Belt—the area of objects in resonances with Neptune, the classical Kuiper Belt, and the Scattered Disk. The latter is the location of Eris and other KBOs with highly eccentric orbits.

Where did Pluto form—in its location, or somewhere else. Various theories attempt to answer this question. One theory, discussed by Dr. Renu Malhotra at the Great Planet Debate, and also discussed extensively in Malhotra's research publications, is that Neptune formed closer to the Sun and then migrated outwards, sweeping objects located closer to the Sun, including Pluto, with it.

The hope is that data from the flyby will answer questions such as what Pluto and Charon are made of, how both accreted, and what their internal structure is. What is known so far is that Pluto and Charon are dense, rock-rich worlds that accreted very rapidly. They probably formed closer to the Sun than their present location.

As I have noted many times in this blog, Pluto is believed to be about 70 percent rock and very likely differentiated into core, mantle, and crust just like Earth. The possibility of Pluto having a subsurface ocean was discussed as well.

Ceres is also estimated to be 70 percent rock and may contain materials brought from the Kuiper Belt region. The small planet is actually more like objects in the Kuiper Belt than like inner solar system bodies, to the point that some astronomers theorize Ceres actually came from the region beyond Neptune.

Also noted was a search for a system of small moons around Haumea, a small, football-shaped planet beyond Pluto in the Kuiper Belt. Haumea is known to have two moons, but as Dr. Luke Burkhart, who conducted a search for additional satellites, noted, no such objects were found.

“Haumea doesn't have a cohort of satellites; Pluto remains unique,” Burkhart said.

These are just the highlights of presentations that were far more intense, detailed, and at times technical.

Kimberly Ennico, New Horizons Deputy Project Scientist, is blogging from the conference, and her posts can be found at http://blogs.nasa.gov/mission-ames/ . You can also follow the discussion on Twitter here, https://twitter.com/search?q=%23Plutosci&src=hash and by following the hashtag #PlutoSci.

The conference has brought together an amazing group of scientists and others who share a fascination with distant Pluto. I personally recognized some from other conferences and many names from scholarly publications I have downloaded and read.

Little mention was made of the IAU. At the same time, debates and disagreements among scholars, such as the question of Ceres' place of origin, were noted genially and recognized as positives that are part and parcel of such discussions. Ideas rise and fall based on data from missions like New Horizons and from studies like those discussed by the speakers. They are not imposed by fiat.

This conference represents the kind of discussion astronomers and others interested in Pluto should be having, a healthy back and forth exchange of ideas. Those who reject such an exchange for simpler but largely unscientific “decrees from on high” will likely be left behind and consigned to irrelevance.

Two important notes: Tomorrow, July 23, Dr. Alan Stern will give a public lecture, “New Horizons to Planet Pluto: Exploring the Frontier of Our Solar System.” The talk will take place at 7:30 PM EDT in the Kossiakoff Center at APL. It will be webcast live at mms://a1232.l711157231.c7111.n.lm.akamaistream.net/D/1232/7111/v0001/reflector:57231

Second, there is a public campaign to get LEGO to make and sell a LEGO model of New Horizons. They have already done this for the Mars Curiosity Rover and for the Japanese Hyabusa cometary mission. We all can help make this happen! The LEGO program is called CUUSOO. A model is created, shared on the CUUSOO web site, and then must get 10,000 individual votes. At that point, it will be reviewed by LEGO and then possibly chosen for production as one of their products, meaning it will be sold online and in stores.

Cast a vote for LEGO New Horizons at http://lego.cuusoo.com/ideas/view/44093 .