the zooniverse.org real science online

The Zooniverse is a collection of websites where members of the public are asked to look at data and interpret it for scientists. This is because many scientists have far too much data to be able interpret it all themselves. The data can be an image, a graph, a video clip or a sound clip.

The Sloan Digital Sky Survey is a telescope that surveys sky every night. It takes millions and millions of images, and astronomers don’t have enough time to look at them all. Some astronomers are particularly interested in galaxies. Computers can find the galaxies in the images, but they cannot identify them. The Zooniverse web developers built a website for the astronomers, called Galaxy Zoo. Ordinary people can go online (galaxyzoo.org) and help the astronomers identify the different galaxy shapes. It’s really easy, all you have to do is answer some simple questions about the galaxy shapes.

350,000 volunteers classifications 150million it’s been very popular!

Visit: Create an account using and address.

Go to ‘Select Group’ and click on ‘Make a New Group’

Fill in the form and click ‘Send Invites’.

Now get started by clicking ‘Classify in Group’ Note: You can invite friends to classify with you by sharing the URL with them!

Now get classifying! If you get stuck, use the ‘Help’ button to look at examples. Otherwise simply answer the questions about the galaxy shapes. Classify at least 30.

Now click the green ‘Group’ icon to return to the Navigator. Note: the ‘SDSS’ button tells us this image was taken by the Sloane Digital Sky Survey telescope. Some of the images were taken by the Hubble Space Telescope (HST)

You can see how many galaxies you have classified. Note: There may be less than 30. This is because only the galaxy images taken by the SDSS telescope have data attached to them. The Hubble images do not have useful information. However, ALL of your classifications will be used by the astronomers.

Click on “My Galaxies” to see how the choices you made for the first questions compare with the choices other volunteers made.

Questions For your last 10 galaxies 1.What is the ‘mode’ classification for each galaxy? 2.What percentage does the ‘mode’ classification get?

Both galaxies have been classified as ‘Smooth’, but they use the vote percentage as a measure of their ‘confidence’ in the classification. Galaxy 1 Mode: Smooth (21 out of 35 votes) 60% of the votes Galaxy 2 Mode: Smooth (17 out of 20 votes) 85% of the votes

Draw and fill out the following table for your 10 galaxies. Galaxy IDClassification (Mode) Confidence (Vote Percentage) AGZ0004d0g (Galaxy 1)Smooth60% AGZ0002pyx (Galaxy 2)Features85%

Questions Looking at your table: 1. An astronomer has some telescope time and they would like a galaxy that has ‘Features or disk’. Which of your galaxies should they choose? 2. Which of your galaxies has the most uncertainty in it’s classification?

Extension The ‘Graph Data’ button allows you to make a histogram or scatter graph of the galaxies properties listed here. -Classify another 70 galaxies -Investigate how these are distributed in a histogram. Are there any differences between ‘Smooth’ and ‘Features or disk’ galaxies? -Compare these properties to each other in a scatter graph. Redshift : Indicates the distance to far-away galaxies and how far back in time we see them. Values range from 0 to 0.7; lower is nearer. Color : The difference in galaxy brightness when observing through red and blue filters. Values range from 0 to 5, lower is bluer. Apparent brightness : Indicates how much red light we have detected from the galaxy. Values range from 13 to 19; lower is brighter. Absolute brightness : Intrinsic brightness of the galaxy, corrected for distance. Values range from -20 to -15; lower is brighter. Absolute radius : A measure of the intrinsic size of the galaxy, corrected for distance. Values from from 0.5 to 25 kpc, lower is smaller.