Month: July 2013

This is part of a blog series on the Pluto Science Conference, “The Pluto System on the Eve of Exploration by New Horizons: Perspectives and Predictions,” held July 22-26, 2013 in Laurel, MD.

New Horizons’ Principal Investigator (lead scientist) is Dr Alan Stern (SwRI/Southwest Research Institute). In his presentation, he gave an overview of the mission concept, the science objectives and mission status. The scientific suite is sophisticated and carries the first student-built deep space instrument. The cruise period spans two Presidential administrations (8 years). New Horizons launched on January 19, 2006, and will fly by the Pluto system with closest approach July 14, 2015. For more information about the mission, do check out the New Horizons Mission Websites: http://pluto.jhuapl.edu/ (JHU APL site) and https://www.nasa.gov/mission_pages/newhorizons/main/index.html. (NASA site).

At a glance, the New Horizons Mission to Pluto and Beyond. Key milestone dates and the spacecraft trajectory (in red).

Measurement-wise, New Horizons’ Pluto fly-by of July 2015 is comparable to Voyager 2’s fly-by of Neptune’s moon Triton in 1989. However, Voyager 2 did not have an infrared mapping nor ultraviolet imaging spectrometer, something New Horizons will have. Also, New Horizons will be flying three times closer to Pluto than Voyager 2 did at Triton.  A snapshot of the comparison highlights from Alan’s talk is below.

Comparison of Voyager 2 data from its fly-by of Neptune’s moon Triton in August 1989, with a “visualization” of what New Horizons’ best resolution at Pluto might reveal during its fly-by of Pluto in July 2015.

The New Horizons’ unique science encounter involves more than 6 months of active science operations, starting in mid-April 2015 when the on-board instrument suite achieves resolution better than Hubble.

A more in depth discussion about “When will New Horizons have better views of Pluto than Hubble does?” can be found in this blog entry on the Planetary Society’s blog site at http://www.planetary.org/blogs/emily-lakdawalla/2013/0218-new-horizons-pluto-better-hubble.html .

For more in-depth information about the New Horizons mission check out a series of a papers published in Space Science Reviews.  Link: http://www.boulder.swri.edu/pkb/

To end this posting, a few fun factoids about New Horizon’s Speedy Performance since Launch.
New Horizons’ Speed Record. Launched on an Atlas V-551 on January 19, 2006 at 14:00 EST, the ~400 kg spacecraft, about the size of a grand-piano, needs to travel 5 billion km (5x10e9 km) from Earth before it can execute the observations for its prime science mission. Launching with a speed of  58,000 km/hr (36,000 mph) and benefiting from a gravity-assist from Jupiter in February 2007 (which boosted the spacecraft speed), New Horizons will reach its destination, Pluto, after ~9.5 years of space flight.

New Horizons Speed Facts:
Launched at 36,000 mph
Passed Moon’s orbit in 9 hours
Passed orbits of:
Mars on 4/7/2006
Jupiter on 2/28/2007
Saturn on 6/8/2008
Uranus on 3/18/2011
To cross orbit of:
Neptune on 8/24/2014
With closest Approach Pluto-Charon on 7/14/2015

New Horizons is a Mission for the Patient (and Persistent). It is a labor of love, dedication, fortitude, with compelling science, top-notch engineering, and tight management. This is an entry part of a blog series covering the Pluto Science Conference, held July 22-26, 2013 in Laurel, MD.

Tom Krimigis (JHU/APL) started off our excited Pluto crowd with an overview of the steps that enabled the New Horizons mission to become reality. Any science mission starts with its science objectives. Successful science mission concepts that make it to launch rely on thorough reviews of its science, engineering, and investment (i.e. cost & feasibility).  New Horizons, owes its existence to both initial scientific grounding work by the scientists in the 1970s and equally also to the persistence of those scientists and supporters at NASA and Congress over the subsequent decades to make it get to flight. New Horizons was selected in November 2001 from a competition and launched in January 2006. It will reach its destination, the Pluto-Charon system in 2015.

A rose by any other name is still a rose. A mission to Pluto has had many names over these past decades and with concepts “varying on a theme.” It was called Mariner-Jupiter-Pluto (MJP), mini Voyager-Pluto Fast Flyby (PFF), Pluto Express-Pluto-Kuiper Express, and now New Horizons, among many mission names.

For more reading about the saga, science, and significance of Pluto exploration, check out Andrew Lawler, Science 295, 32-36, Jan 4, 2002. “Planetary Science’s Defining Moment.” at http://www.sciencemag.org/content/295/5552/32.full.pdf  (requires login access) or find it herefrom the author’ website here.

Pluto Not Yet Explored (lower right) from USPS Stamp Series (1991)

The mind of a scientist understands, embraces, and executes the scientific method, the process by which an idea is created, then tested by experiment or model, validated or refuted, and then, when validated, culminates in the description of the results to the larger community through a publication. The cycle begins again, sometimes building on previously published work, or in some cases, the birth of new ideas to the scene, most likely inspired by previous knowledge.

A key component to a scientist’s work is the attendance and interaction with colleagues at scientific conferences. At such gatherings we can see examples of the scientific method in a multitude of stages: the birth of a new idea, the suggestion of methods to carry-out the experiment or computation, a presentation that disproves an approach requiring the scientist to start anew, through the description of the results of the recent experiment or computation.

~150 people are to gather this week at the Johns Hopkins University Applied Physics Laboratory in Laurel, MD to share ideas, debate hypotheses, and explain experiments related to the emissary from our Solar System’s Third Zone, the dwarf planet Pluto and its moons. The timing is crucial to have these conversations because in two years from now, in July 2015, NASA’s New Horizons Spacecraft will do a close fly-by of the Pluto system, a system never before visited by another spacecraft. The forum provides an update of the mission and its measurement capabilities and encourages healthy dialog among theorists who have predictions, laboratory spectroscopists who can build examples of chemistry happening on these icy bodies, and observers who have been monitoring and documenting the changing nature of Pluto and its environment.

Details about the Pluto Science Conference, “The Pluto System on the Eve of Exploration by New Horizons: Perspectives and Predictions,” can be found here at
https://dnnpro.outer.jhuapl.edu/plutoscience/Home.aspx.

You can follow the New Horizons mission status at any time by visiting the New Horizons Mission Website at http://pluto.jhuapl.edu/ and https://www.nasa.gov/mission_pages/newhorizons/main/index.html.

I’ll be providing summaries of the meeting content and discussions through a series of blog posts this week. For now, I’ll leave you with some things we do know about Pluto and its largest moon Charon.

The diameters of Pluto & Charon shown with respect to the USA for scale.

What do we know about Pluto so far?

• Highly elliptical (e = 0.25), Highly inclined (i = 17 deg), 248 year orbit
•  Rotational period of 6.387230 days
•  Small (diameter = 2328 ± 42 km), Rock/Ice object (“Icy Dwarf”)
•  Density is 2.03 ± 0.06 g cm^-3, Mass = 0.0022 M_Earth
•  Bright surface frosts of N₂, CH₄, CO, and C₂H₆  produce albedo of ~55%
•  Highly variegated surface (bright and dark regions)
•  Reddish in color, probably due to surface organics
•  Tenuous, variable atmosphere (mostly N₂; 2-10 µbars at the surface & going up)

What do we know about Charon?

• Discovered, by accident, in July 1978 by James Christy (USNO)
•  In circular orbit ~19,573 km from Pluto, with a 6.3872273 day period
•  Tidally-locked spin period (i.e., spin-orbit synchronous)
•  Diameter is 1212 ± 3 km (about half of Pluto’s Diameter: “Binary Planet”)
•  Density is 1.66 ± 0.06 g cm^-3 (vs 2.03 ± 0.06 g cm^-3 for Pluto)
•  Surface has crystalline H₂O-ice and NH₃-hydrate (recent?)
•  Average albedo ~35%, neutral color (variegation change over time?)
•  Average T ~ 50 K, low thermal inertia (high porosity)
•  No atmosphere detected yet (~10-300x lower pressure than Pluto’s)

(left) Charon Discovery Image July 1978; (right) New Horizons’ LORRI instrument spots Charon July 2013 from 6AU away.

To Pluto and beyond!