Date: July 18, 2011
Title: The Discovery of Neptune’s Thirteen Moons, Part 2
Podcaster: Diane Turnshek
Organization: Carnegie Mellon University
Description: Neptune has now completed one orbit around the Sun since its discovery 165 years ago. In that time, the pattern of discovery of Neptune’s moons serves to illustrate how the process of science itself has changed, from one man, working alone, to hundreds of researchers working together on satellite mission teams. In Part I (July 15), we looked at the past and how each of the thirteen moons of Neptune was discovered and in Part II (July 18), we look to the future at how the fourteenth and beyond will be found. Many people wish to experience firsthand the excitement of scientific inquiry and scientists have learned to share—by using citizen science. We discuss a new Hubble archival data project that, with the help of skilled volunteers in the Zooniverse, may turn up additional satellites in our solar system.
Bio: Diane Turnshek teaches astronomy at the University of Pittsburgh, St. Vincent College and Carnegie Mellon University, where she also coordinates physics outreach. She hosts a monthly public lecture series at Allegheny Observatory. In her outreach role, she has visited schools, libraries, camps, Scouts and Congress and podcasted with Gateworld.net (“The Science of StarGate 1 and 2”) and 365Daysof Astronomy.org. Diane consults with people who wish to use accurate science, from SF authors to opera companies. Find her short fiction published in Analog Magazine and elsewhere.
Hi, this is Diane Turnshek. Welcome to 365 Days of Astronomy.
On the 15th of July, I speculated about the changes that are happening in discovery science as relates to Neptune and its moons. From one man, alone at night by the telescope, to huge conglomerates of authors working together to find new objects in our solar system. The discovery process highlights a fundamental change in the way science is being done today. The solitary discoverers are all but gone. This is one of the points in Robert Park’s “Seven Warning Signs of Bogus Science,” originally written to advise federal judges, but useful for us all. He says, “The image of a lone genius who struggles in secrecy in an attic laboratory and ends up making a revolutionary breakthrough is a staple of Hollywood’s science-fiction films, but it is hard to find examples in real life. Scientific breakthroughs nowadays are almost always syntheses of the work of many scientists.”
Does this mean astronomical discoveries can no longer be made outside the large groups of astronomers with doctorates working at research institutions using humongous telescopes or satellites launched years ago? Not at all. A new discovery method has arisen to make use of the raw talent and enthusiasm of ordinary people who enjoy astronomy’s universal appeal.
The key was to realize that many people wish to experience firsthand the excitement of scientific inquiry. Discovery often requires searching through vast data sets. Humanity is not yet at the stage where we can direct computers and robots to find all the answers we seek. We still need human hands to guide the search and human eyes to find the natural patterns. We have more data than we can reduce in a timely fashion and this has given rise to citizen science, programs that educate and engage people in the pursuit of the answers to the questions about the universe. There’s excitement in this kind of investigation and scientists have learned the value of sharing.
Citizen science has enjoyed enormous success, especially in astronomy. The government funds the organization of science networks to classify galactic mergers, look for new lunar features (and debris from spacecraft), track variable stars, monitor solar flares and find supernovae. Privately-funded programs extend the list to, for example, the search for extraterrestrial radio messages. Even in a city, young scientists can go outside, look at magnitudes of certain stars and report on the local light pollution levels for international efforts like the Great World-Wide Star Count and Globe at Night. New programs come online often in this international scientific community. Citizens are introduced to the background concepts via online tutorials and then work on whatever survey experiments they find appealing for as long as they wish. Galaxy Zoo alone can boast that 150,000 citizens classified millions of galaxies from the Sloan Digital Sky Survey and users found a new class of object now known as Galaxy Zoo peas. The Zooniverse portal and Citizen Science Alliance attract visitors from all over the planet, skilled volunteers in scientific endeavors directed by scientists.
Ice Hunters is a newly-released citizen science project designed to find Kuiper Belt Objects (KBOs) in the specific region of the solar system that will be targeted by the New Horizons probe. The Kuiper Belt is a region aligned along the plane of the solar system and encompassing an area that’s 30 to 55 times the distance from the Earth to the Sun (1 AU). This spacecraft was launched in 2006 and is already half way to its destination, the Pluto system. What’s it designed to do? Take high resolution images in the visual and infrared, look for an atmosphere, count and catalogue moons, do infrared spectroscopy and four color mapping to determine the surface make-up, and look for rings. The New Horizon’s probe will focus on the system for five months and then retarget to acquire the same sort of information on two, more distant objects in the Kuiper Belt.
Citizen scientists are sifting through thousands of images in a small area of the sky (two square degrees, in the direction of the constellation Sagittarius). These images were for the most part taken with ground-based telescopes: the 8-m Subaru telescope on Mauna Kea or the 6.4-m Magellan telescope in Chile. Seekers are spotting slow moving objects that can be identified as KBOs. Remember, when the data is properly calibrated, and multiple exposures are viewed simultaneously, star images don’t move and asteroids (which are closer to us) leave much longer streaks than KBOs. Another challenge, when searching for KBOs in this way, is to identify variable stars. Plenty will be found and they’ll be catalogued for later use. Hopefully, by the time the probe reaches Pluto, we will have happily spent hours
Next spring, a new citizen science project will unfold, designed to identify interesting solar system objects (new asteroids, comets and KBOs), features on the planets (storms, meteor impacts, geysers) and potentially find new planetary satellites. Coordinated by Max Mutcher, this program will use archival images from the Hubble Space Telescope (HST), 10,000 datasets taken over the course of fifteen years. He knows very well the excitement of discovery–in 2005 he found Nix, a moon of Pluto, using this same archival data method. He will oversee nine others in the development of a web interface that allows citizen scientists access to HST archival images through the Zooniverse with specific tasks set up for the public to accomplish.
One of the team members, Dr. Alberto Conti, the NASA Multi-mission Archive Scientist at the Space Telescope Science Institute has shared some pictures and the procedure that is being implemented. The first step: process the data from the Hubble Wide Field Planetary Camera 2 creating a calibrated, searchable database. Uniformly-processed and well-documented, this “Planet Pipeline” will be ready for both astronomers and citizen scientists. A citizen science user may choose to explore several regions, for instance the area around a planet.
A user could drag a diagram showing the location of the moons over a photograph and align all the visible moons. Images taken directly before and after can be compared, making obvious any movement of objects in the field. Software will be available to determine magnitude, mass, distance from planet and orbital characteristics. Artifacts in the data must be recognized, cosmic ray strikes for instance. Ghostly images that are visible in one frame and gone in the next are not real—they are caused by high energy, charged particles striking the camera.
As the months progress, testing of the tutorials and software will take place, first by the science team, next by experienced Zooniverse users, then with novice users, for instance visitors at science museums. Incentives are provided for citizen scientists, including possible inclusion on the author list of research papers that use their images. Can it get better than that?
What would you like to explore today?
• A planet?
Thanks for listening to 365 Days of Astronomy. This is Diane Turnshek, signing off.
Robert Park’s “Seven Warning Signs of Bogus Science”
Citizen Science Alliance
Special Neptune edition of Argentus
End of podcast:
365 Days of Astronomy
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