“Disk Detective” may seem like a fun computer module, but it is much more than that. It is a great way to get the public engaged in astronomy by allowing people to identify disks for extrasolar planets. These disks are produced when planets form clouds of dust, debris, and rock in the shape of disks with stars in the center. The debris disks, also known as “YSO disks,” can be categorized according to their gas content and age. Astronomers have been hard at work to find these disks for the past three decades. It is tough to identify the disks because they are presented among other images that the telescope picks up, such as galaxies, nebulae, and other artifacts created by the telescope itself. Ultimately, the main goal of Disk Detective is to allow people to find planets around other stars and assist astronomers to get more sets of eyes on the debris disks data that is provided by Wide-field Infrared Survey Explorer (WISE), the Two Micron All Sky Survey (2MASS), the Digitized Sky Survey (DSS), and the Sloan Digital Sky Survey (SDSS). Disk Detective was developed by NASA and is funded by Zooniverse, whose goal is to use this program to publish scientific results as astronomers deem appropriate.

The images on Disk Detective are presented in a flipbook with “play” and “pause” buttons to control the rate at which the images are viewed from short to long wavelengths. Those images were taken from several different telescopes. They appear to be photographs of the night sky, in which the background is mostly dark, empty space, which is considered to be noise. In the images, the bright objects will appear to be white or light blue. A small white, glowing circle of light is in the center of the image. If that glowing ball of light is in the center of the red-marked circle with red crosshairs to mark the middle point, then it is a good candidate to be a debris disk. However, if the white light appears to surpass the red circle, it is not a good candidate to be a disk. Good candidates can also be white light that does not appear as a circular ball of light, but rather has diffraction marks slightly outside of the red circle. On the same screen, there is also a link to a “talk” page, in which a participant can discuss other spots that appear on the image beyond the red circle. Another interesting aspect of the program is that there is a “collect” page, which can be used to create a collection of one’s favorite images. Disk Detective allows users to comment on their own images as well as the images of other observers.

In order to determine whether the image viewed is actually a star with a disk or just debris, the SED or Spectral Energy Distribution must be analyzed, which is a plot of how bright the object is, including the infrared wavelengths shown in each of the images in the flipbook. There is a “more info on SIMBAD” link, which presents the participant with a database about astronomical objects, such as stars, planets, and galaxies. SIMBAD labels the object that the observer identified on Disk Detective to determine whether it is the disk of an extrasolar planet. However, the software does not include all of the possible objects that an image could contain. It also may be wrong when identifying one’s disk, so it is a useful resource, but not the most reliable. When identifying the images on Disk Detective, there are six options that can be chosen to classify the object seen: multiple objects on red circle, object moves off the crosshairs, extended beyond circle in WISE images, empty circle in WISE images, not round in DSS2 or 2MASS images, and none of the above/ good candidate. The program also records the identifications made in one sitting.

Although Disk Detective is a great program to get individuals more interested in astronomy, after making numerous identifications, the system does not interact with the observer. Therefore, one improvement would be to provide instant feedback after an identification has been made rather than allowing the participant to search for further information on their own. Disk Detective could hold the attention of adolescents to adults when they make their first identification, but unless they are extremely fascinated by astronomy, they would get bored because the images do not vary much. Most of the images are in the same small frame with the black sky in the background and red circle with a round ball of white light to identify as a disk. Perhaps, another improvement would be to increase the size of the screen in which disks can be identified. Therefore, more of the night sky can be seen along with other stars and debris, which may make identifying a disk even more challenging, but fulfilling for the participant. It would also be less monotonous if the images included planets and constellations that people are already familiar with in order for them to see the rest of the solar system as they classify disks. If the images are more aesthetically pleasing, this program can attract more people to participate who would not normally be interested in anything science-related. Overall, Disk Detective is a decent program for those who have background knowledge about astronomy and want to get a taste of what astronomers do for a living, but various improvements can be made in order to appeal to more individuals. The program can be found on http://www.diskdetective.org/#/classify.