Crowdsourced astronomy: quietly popular astronomy for public science

Author: Shi Wei

Astronomy is the oldest natural discipline and one that relies particularly on public participation. How has astronomical citizen science undergone? Can seemingly sophisticated astronomical research really attract the participation of the general public?

Citizen Science and Citizen Scientists

Citizen science is scientific research (in whole or in part) conducted by non-professional (i.e., amateur) scientists or the general public, including both professional scientific research with public participation and scientific research carried out by the public independently [1]. A citizen scientist is someone who voluntarily invests their time, energy, expertise, and data into joint scientific research every day.

The term "citizen science" was coined by the British scholar A. Irwin. Irwin) and the American scholar R. Bernie Bonney) was proposed independently in the mid-90s of the 20th century. Erwin focuses more on how the public can participate in scientific affairs on a more equal footing and promote the better development of science; Bernie is mainly concerned with how the public can participate in scientific research activities, thereby improving the efficiency of scientific and technological innovation [2]. Although the concept of "citizen science" has been proposed for less than 30 years, citizen science activities have long existed. Broadly speaking, before the birth of professional "scientists", people habitually observed the habits of animals and plants, observed the movement of the sun, moon and stars, or checked their physical condition, which were typical public science activities. Citizen science activities are usually derived from personal interests, but they are more targeted and professional than interest alone, which is considered to be an important basis for distinguishing "citizen scientists" from "science enthusiasts". Astronomy is a discipline in which the public sciences are highly engaged, and it has traditionally referred to these two groups as "citizen astronomers" and "amateur astronomers" respectively.

Based on an online survey, the Citizen Science Association outlined four typical characteristics of citizen science activity that differ from traditional scientific research [3]:(1) extensiveness, that is, anyone can participate; (2) Normative, that is, participants can enter, verify and combine data with high quality using the same protocol as professional researchers; (3) practicality, i.e. participants collaborate with professional researchers to solve real scientific problems, not just demonstrate scientific concepts; (4) Sharing, that is, participants cooperate extensively with professional researchers and volunteers to share the obtained data with the public and scientists. To a certain extent, these typical characteristics explain that "citizen science" is also an important part of scientific research, and it must also face scientific problems, follow scientific logic, use scientific methods, use scientific tools, share scientific results, and abide by scientific ethics. It should be pointed out that from these characteristics, some so-called "citizen scientists" do not carry out "citizen science" because they do not accept the general scientific understanding and reject the research model of the scientific community.

Public science first appeared in nature, ecology, astronomy, phenology, environment and other disciplines, because these disciplines are based on observation and observation, with the collection of samples, specimens and records as a means, the research objects involved are relatively close to the public, the difficulty of basic observation is not too high, and it is easier for ordinary people to participate. These disciplines have relatively heavy observation tasks, and the participation of the public in them is of great benefit to professional scientists collecting data, and helping to expand the scope of observation and increase the number of samples is the greatest contribution of citizen science to scientific research.

Amateur astronomer in history

To some extent, modern astronomy began as a manual job that today seems "amateur." In 1609, the Italian astronomer Galileo Galileo made a telescope on his own based on the invention of the Dutch optician. In Galileo's view, telescopes are not only "fun" objects, but also play an important role in military and scientific affairs. He pointed the telescope at the sky, and since then the human gaze has continued to extend into the depths of the universe. In the following century, astronomical telescopes have made great strides and have been promoted and popularized at the public level. At the end of the 18th century, there was already a distinction between "professional astronomers" and "amateur astronomers" in Europe, the former mainly referring to astronomers engaged in research and teaching at national or educational observatories, and the latter mainly referring to enthusiasts who built their own observatories or telescopes for personal interest.

The discoverer of Uranus and one of the founders of astrophysics and stellar physics, F. Herschel. W. Herschel) is the poster child for amateur astronomers. Originally an organist at Bath Abbey, he became interested in mathematics, physics and astronomy in the study of musical rhythms, and began to make his own astronomical telescope in 1773, and by 1776 had built a large reflecting telescope with a focal length of 6 meters and began to conduct sky surveys. In 1781 Herschel became famous for the discovery of Uranus. In 1782, King George III, who also loved astronomy, hired Herschel as a private astronomer. In 1821 he was elected the first president of the Royal Astronomical Society , and he became almost a professional astronomer. There are many other famous amateur astronomers in history, such as the brewer R. Carrington. C. Carrington) continued to depict sunspots, discovered the poor rotation of the sun, and recorded an unprecedented solar flare event, which opened up a new understanding of solar activity; British engineer and businessman Roberts (I. Roberts) mounted a camera on a telescope and invented "piggyback" astrophotography that revolutionized the way humans studied astronomy; E. Barnard, an American photographer with never a formal education. E. Barnard not only independently discovered 14 comets, but also discovered stars with the largest proper motions, pioneering "galactic photography".

Astronomy itself is very focused on observation, so observation is the most important activity of amateur astronomy research. From the 18th century to the 20th century, the main working method of amateur astronomers was to make observations through telescopes and faithfully record the results of observations by taking notes, drawings, photographs, etc.; The main observation targets include the Sun, Moon, planets, stars, comets and meteor showers, as well as deep-sky objects such as nebulae, star clusters, and galaxies. Although there are only a handful of amateur astronomers like Herschel, Carrington, and Roberts, who are later regarded as "professional astronomers", many amateur astronomers have made new discoveries throughout Europe. After all, the sky was too wide, and the number of global observatories and professional astronomers at that time, as well as the "weapons" in their hands, were not enough to cover the entire sky, so the observations of amateur astronomers could well compensate for the work of professional astronomers. In particular, celestial objects or celestial phenomena such as comets, meteor showers, variable stars, and supernovae have great contingencies in time and space, and amateur astronomers and even more ordinary astronomers have certain "opportunities". For example, D. Levi, one of the discoverers of comet Shoemaker-Levy 9, the protagonist of the 1994 "Comet-Wood Collision", Levy) was a popular science writer at the time; Mainland amateur astronomer Zhou Xingming has independently discovered many comets such as C/1983 H1 (but unfortunately, due to communication and other reasons, the release time is later than foreign enthusiasts, he does not enjoy the honor of "discoverer"). In fact, there are still cases of amateur astronomers discovering comets, but due to the great improvement of professional astronomical observation technology, it has become increasingly difficult for amateur astronomers to obtain these new discoveries.

Flourishing amateur astronomy

The impact of technological innovation on amateur astronomy

Every technological innovation, although it will bring a qualitative leap to professional astronomy research, is often a "blow" for amateur astronomers. The development of large-aperture sky survey telescopes, charge-coupled devices (CCDs), adaptive optics (AO) and other technologies has made the hardware level difference between professional astronomers and amateur astronomers and astronomers more and more large, and further squeezed the "living space" of amateur astronomers. Examples include the Lincoln Near-Earth Object Research, the Near-Earth Asteroid Tracking, the Panoramic Survey Telescope and Rapid Response System, and the Catalina Sky surveys, such as the Sky Survey and the Asteroid Terrestrial-impact Last Alert System, are more efficient and can detect a large number of faint asteroids and comets. Among them, the Lincoln NEO Research Project discovered 230,000 small solar system objects (including 279 comets) [4].

Of course, technological innovation will also benefit amateur astronomers, mainly reflected in the following four aspects: (1) the reduction of the cost of telescope systems (including optical systems, mechanical systems, electronic control systems, etc.), so that amateur astronomers can obtain small telescopes with good imaging and easy operation; (2) The popularization of photosensitive elements such as professional CCD, CMOS (complementary metal oxide semiconductor), digital cameras and even spectrometers allows amateur astronomers to use small telescopes to obtain better digital photos, and the effect is at least equivalent to the photos taken by large telescopes of professional observatories 50 years ago; (3) With the rapid development of computer miniaturization and network information technology, the Robotic Autonomous Observatory technology was born, and amateur astronomers can avoid urban light pollution and air pollution by establishing remote observatories, which shortens the gap between "amateur" and "professional" to a certain extent; (4) The confirmation and promotion of standard data formats such as the Flexible Image Transport System, as well as the popularization of open source software, give amateur astronomers the opportunity to use professional control software and analysis software for data processing. These changes enriched the observation methods of amateur astronomers, greatly improved the efficiency of observations, and gradually changed the research field and research methods of amateur astronomy. These lower technical barriers also facilitate pro-am collaboration.

Development of amateur astronomy in mainland China

In the past 10 years, amateur astronomy on the mainland has shown a vigorous development trend, and more than ten remote observatories have been built in various places. Among them, the Xingming Observatory (IAU number C42), built in 2007 and located in the Nanshan Observatory of the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences, is the most fruitful. As of August 2022, the observatory has more than ten small and medium-aperture telescopes, operating nearly 10 observation projects using "unattended" remote control, and has discovered 3 comets, 11 asteroids (permanent number), 63 supernovae, 43 novae, 27 dwarf novae, and 198 variable stars [5]. Other active amateur observatories on the mainland include the North Corona Observatory (IAU number N55), Shikiyama Observatory (IAU number G26), and the Green Field Observatory (IAU number P34), which also carry out asteroid search and photometry. Unfortunately, most other remote observatories in China are dominated by astrophotography, which hardly involves scientific research, and is still far from true amateur astronomy (or public science) [6].

Star Tomorrow Observatory (photo by Ren Li)

Transforming Citizen Science – Crowdsourced Astronomy

The origin and constituent elements of crowdsourced astronomy

In the past 20 years, with the development of computers, network information and other technologies, astronomy has entered the era of big data. For example, the Sloan Digital Sky Survey (SDSS), which opened in 2000, collected more data in its first few weeks than all the data collected in the history of astronomy combined, accumulating more than 140 terabytes (terabytes) of information to date. China Sky Eye (FAST) collects up to 38 gigabytes (GB) of data per second, and tens of petabytes (petabytes) of new data is added every year. The Square Kilometre Array, the largest future international cooperation project for radio telescopes, will consist of thousands of antennas, generating about 14 exabytes (exabytes) of data per day and storing 1 petabyte of data [7] (1 exabyte = 1024 petabytes, 1 petabyte = 1024 terabytes).

The sheer volume of data gives astronomy research more samples and more opportunities to discover new targets, but professional astronomers seem to be overwhelmed by the data. While the development of artificial intelligence will certainly help them process data more efficiently, noise in astronomical data often creates great obstacles for artificial intelligence. Some important discoveries often exist in "atypical" patterns, and if artificial intelligence is "not well-skilled", it is very likely to misjudge or miss the judgment. The participation of amateur astronomers and astronomers can rely on the advantages of the human brain and the number of people to help artificial intelligence carry out deep learning, thereby helping professional astronomers to fill in the gaps.

In this context, a new style of citizen science activity has emerged - crowdsourcing science. The concept of "crowdsourcing" was developed by Wired magazine reporter J. Howey. Howe) refers to a company or organization that outsources work tasks in a free, voluntary manner to a non-specific, larger public (or volunteer). Crowdsourcing is initiated by a company or institution, and the task is usually undertaken by individuals, but multiple people can collaborate when necessary. Crowdsourcing science is an emerging scientific research method that dynamically links relevant people, data and ideas in scientific research through network technology, across the boundaries of time, space and traditional scientific research organizations, in order to improve the efficiency and quality of mission completion [8].

Crowdsourcing science consists of five main elements [9]. First, the contracting party: usually a scientific research institution or organization, but also an individual. Second, the public: ordinary people who are not employees of the institution (or organization) who are willing to participate in scientific research and other activities; Often there are no high demands on their skills. Third, clear tasks: the contractor puts forward specific goals and needs, which are usually relatively simple; With simple training, participants are equipped with the skills to complete the task. The fourth is the form of completing the task: the contracting party proposes specific methods and channels for public participation. Fifth, the network platform: distribute tasks to the public through the network platform and collect the results completed by the public.

Typical crowdsourced astronomy projects abroad

Galaxy Zoo is a representative crowdsourced astronomy project abroad.

In 2007, K. Shovinsky, an astrophysicist at the University of Oxford, England. Schawinski needed to process the massive images collected by SDSS to identify and classify objects that resembled galaxies for deeper study. The SDSS project, which began in 2000, uses the 2.5-meter aperture large-field telescope at the Apache Point Observatory in New Mexico to conduct multispectral imaging and spectral redshift survey observations of galaxies, covering more than 35% of the total area of the day, obtaining photometric information on about 1 billion objects and spectral information on more than 4 million objects. In the face of such a huge amount of data, the number of professional researchers is very small. For any astronomical study, classification is the most basic work: first, it is necessary to distinguish whether those star spots or spots on the photo are stars or distant galaxies; Second, galaxies need to be classified. Inspired by an early crowdsourced science project, Search for Extraterrestrial Intelligence (SETI), Schowensky and other researchers designed the Galaxy Zoo. In May 1999, the SETI@home Project was launched, a scientific experiment program that uses globally networked computers to jointly search for extraterrestrial civilizations; It uses distributed computing, that is, using the idle processing power of the public's personal computers to analyze data and jointly search for intelligent life beyond the earth. Although the lack of "human" participation SETI@home the use of personal computers is not truly citizen science, it provides ideas for the SDSS project team.

At first, the Galaxy Zoo project team expected 20,000~30,000 people to participate in the classification of about 900,000 galaxy samples, which is already an excellent graduate student who works 24 hours a day without food or drink, 7 days a week, for 3~5 consecutive years. Due to the publicity in place, the effect of the project far exceeded expectations, more than 100,000 volunteers were registered to join, and more than 40 million (times) of classification were completed in only 175 days after the project was officially launched, with an average of 38 identifications per galaxy. The program's concise tips and simple operation methods allow participants to easily contribute to academic research on their own computers without any professional background, expertise or special training. Subsequently, it has reaped exciting results, including more than 360 published papers (as of June 2022) and generated some open-source analytical datasets, such a huge success to show the world's strong combat power of public science in the current technological context. Today, the Galaxy Zoo project has expanded beyond astronomy and galaxies, expanding to hundreds of projects in 12 categories such as science, humanities, and art, and has been upgraded to become the Zooniverse.

Typical crowdsourced astronomy projects abroad include Planet Hunters.

Part of the astronomical project in Zooniverse

Search for strong gravitational lensing through Zooniverse's Dark Energy Sky Survey (DES).

Astronomy crowdsourcing project in China

In China, crowdsourced science projects in astronomy have also developed considerably, with the largest and more influential projects mainly being the Public Supernova Project (PSP) and the Pulsar Search Program.

PSP is one of the new cosmic object search projects jointly carried out by the Star Observatory and the China Virtual Astronomical Observatory (China-VO) for the public, and it is also the first crowdsourced scientific project based on domestic amateur astronomical observation data, and it is also a successful attempt of in-depth cooperation between professional astronomical teams and amateur astronomical teams. The original intention of the PSP is to give any ordinary person interested in the search for new objects the opportunity to participate in professional astronomical discoveries, and does not require participants to have special basic knowledge of astronomy. In the PSP system, participants only need to look at the map, search, and report suspicious targets if they are found. Specifically, if a supernova appears in a galaxy, there will suddenly be an extra star point in the picture of that galaxy; Participants compare the new photographs with historical photographs (reference standards), and if new star points are found that match the supernova characteristics, they can be submitted to the system, reviewed and announced by advanced users or administrators, and then confirmed by spectroscopic identification by observatories around the world. In normal operation, the observatory can track thousands of galaxies in a single night. Although the amount of PSP data is not as large as Galaxy Zoo, it has a user-friendly interactive experience and a systematic management process. Since its launch in 2015, more than 10,000 users have participated, far exceeding the number of professional astronomers in China; More than 50 amateur astronomers and astronomers from all over the country have made important discoveries such as 21 supernovae and 12 extragalactic novae through the platform.

The Pulsar Finding Project is a simple mobile version of the public science activity jointly launched by the "China Sky Eye" team and Alibaba's public welfare organization. Participants in the program only need to browse a few sets of pictures on their phones and tick off the signals of suspected pulsars, which can help the system perform machine learning to screen out more reliable pulsar sources. From its launch in early September 2019 to mid-March 2022, it has been viewed with more than 10 million images, helping the FAST team identify and screen pulsar sources.

There is no doubt that after about 20 years of rapid development, citizen science has become more and more popular in astronomy research and is widely used in some important scientific research projects, especially sky survey projects. Citizen science projects have proven to be a very efficient research tool. Not only that, citizen science plays an irreplaceable role in improving the public's scientific literacy and enhancing the public's awareness of participating in scientific activities.

We are pleased to see that with the use or imminent use of large-scale scientific devices such as FAST, the "Guo Shoujing" telescope (LAMOST), and the Sky Survey Space Telescope (CSST), some scientific research teams in the mainland are actively developing a number of public science projects, involving gravitational lensing, fast radio bursts and other frontier fields. At the same time, with the deepening of the popularization of science, the community of astronomy enthusiasts is growing rapidly, and the enthusiasm of the public to participate in astronomy activities is high. In a survey involving 105 participants, 64.76% of the participants expressed their willingness to participate in crowdsourced scientific projects and assist in astronomy research. With such a public foundation, and the support of computer network information technology and big data technology, public science will show stronger vitality and play a more important role in the future.

Shi Wei: Shanghai Planetarium (Shanghai Science and Technology Museum Branch), Shanghai 201306. [email protected]

Shi Wei: Shanghai Astronomy Museum, Shanghai 201306.

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Keywords: citizen science amateur astronomy crowdsourcing science ■