Galaxy Zoo
Citizen Science on Rails
Arfon Smith

Citizen science?

:-(

:-)

700,000
Images

20,000
Users

40,000,000
Inspections

Awesome

Astronomy?

100
80
60
40
20
0
Professor

10,000
7,500
5,000
2,500
0
Professor Paper

50,000
37,500
25,000
12,500
0
Professor Paper PhD

1,000,000
750,000
500,000
250,000
0
Professor Paper PhD SDSS

70,000
60,000
Classifications per hour
1
50,000
Kevin weeks
40,000
30,000
20,000
Fukugita et al. 2007
10,000
0
0 6 12 18 24 30 36 42 48
Hours

1,000,000
Galaxies

170,000
Users

70,000,000
Classifications

70,000,000
Does it work?
Classifications

You bet

Clean Super Clean

Clean Super Clean

Clean Super Clean

better than the
professionals

1. Collaborators not users
2. Contribute to real research
3. Don’t waste people’s time

Land K., et al., 2008, Galaxy Zoo: The large-scale spin statistics of spiral
galaxies in the Sloan Digital Sky Survey
Lintott C.J., et al., 2008, Galaxy Zoo: Morphologies derived from visual
inspection of galaxies from the Sloan Digital Sky Survey
Bamford S.P., et al., 2008, Galaxy Zoo: the dependence of morphology and
colour on environment
Slosar A., et al., 2008, Galaxy Zoo: Chiral correlation function of galaxy spins
Schawinski K. et al. 2009, Galaxy Zoo : A sample of blue early-type galaxies at
low redshift

250,000
Galaxies

225,000
Users

28,000,000
Classifications

70,000,000
What ’s next?
Classifications

1
#

Contribution
to research

Galaxy Zoo
Database

Galaxy Zoo Crow Zoo Moon Zoo Papyrus Zoo
Database Database Database Database

Task
Project
Annotation
User
Asset
Answer

Question 1
Question 2 Question 3 Question 4
Question 5 Question 6 Question 7
Question 8 Question 9

HAProxy
Web
Web Web
HAProxy
API API
MySQL Master MySQL Slave MySQL Slave

Questions?