Home Store Project Ideas Project Guide Ask An Expert Blog Careers Teachers Parents Students

Finding the Center of the Milky Way Galaxy Using Globular Star Clusters

Difficulty
Time Required Average (6-10 days)
Prerequisites None
Material Availability Access to the Internet is required.
Cost Very Low (under $20)
Safety No issues

Abstract

The Milky Way is the edgewise view of our home galaxy, a disk made up of billions of stars. The Sun resides on one of the spiral arms of the disk, 30,000 light-years from the thick hub of the galaxy. The actual center, with a black hole 3-4 million times the Sun's mass, is hidden by dust clouds in space. In this astronomy science fair project, you will use astronomical data to locate the center of this galaxy.

Objective

The objective of this astronomy science fair project is to use Internet-based software tools and databases to locate the center of the galaxy, based on the distribution of globular clusters.

Credits

Jacob Arnold and Jean Brodie, University of California. Santa Cruz, Department of Astronomy

Edited by David Whyte, PhD, Science Buddies
Edited by Sandra Slutz, PhD, Science Buddies

Cite This Page

MLA Style

Science Buddies Staff. "Finding the Center of the Milky Way Galaxy Using Globular Star Clusters" Science Buddies. Science Buddies, 22 May 2014. Web. 22 Aug. 2014 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p032.shtml>

APA Style

Science Buddies Staff. (2014, May 22). Finding the Center of the Milky Way Galaxy Using Globular Star Clusters. Retrieved August 22, 2014 from http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p032.shtml

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.


Last edit date: 2014-05-22

Introduction

Our solar system is located nearly 25,000 light-years from the center of our Milky Way galaxy. We now know that we live in a spiral galaxy, consisting of billions of stars, and that our galaxy is just one of hundreds of billions of galaxies in the universe. However, the location of our Sun in the Milky Way, the size of our galaxy, the number of stars in it, and its structure were all unknown just 100 years ago. During the early 20th century, astronomers were trying to answer these questions using a variety of techniques. You will use one such method to determine the location of the center of our galaxy.

The most direct approach, adopted by Jacobus Kapteyn in order to determine the structure of the Milky Way, inferred distances for a number of stars in various directions to create a 3-dimensional view of our galaxy. Kapteyn found that our Sun lies at the very center of a nearly spherical distribution of stars, and he incorrectly concluded that we lie at the center of the galaxy. What Kapteyn was unaware of was that our galaxy is filled with starlight-absorbing dust, or interstellar dust. This means that stars far away from our Sun appear dimmer or are not even visible from Earth. This effect means we preferentially see the stars nearest to our Sun and cannot easily observe the other side of the galaxy. Therefore, this is not a good technique to use in determining the structure of the Milky Way.

Instead, you will adopt a method, used by Harlow Shapley, that correctly infers the direction of the center of our galaxy. Throughout most of the galaxy, stars are separated by a few light-years. However, globular star clusters contain anywhere from 10,000 to 1 million stars, densely packed into a region only a few tens to a few hundred light-years wide. Figure 1 shows a nearby galaxy surrounded by globular clusters. Because globular clusters contain so many stars, they are much brighter than individual stars and can be seen in the Milky Way, even at very far distances. Unlike stars, which tend to rotate around the Milky Way Galaxy in a flattened disk, globular clusters are distributed in a roughly spherical distribution around the center of the Galaxy. Thus, if we look toward the center of the Galaxy, we should see more globular clusters than if we look in the opposite direction.

Image of Sombrero Galaxy
Figure 1. The famous Sombrero galaxy (M104) is a nearby bright spiral galaxy. The prominent dust lane and halo of stars and globular clusters (globular clusters are the bright white spots) give this galaxy its name. (Wikipedia, 2009.)

In this science fair project, using a compiled list of the Milky Way's globular clusters (approximately 150), you will count the number of clusters found in each constellation. Constellations, like the Big Dipper or Orion, serve as a way to orient ourselves and define directions in our galaxy. You will determine which top three constellations contain the most globular clusters, and therefore, in which direction most Milky Way globular clusters exist. Using Google Earth in sky mode, you will determine a best-guess location for the center of the galaxy and compare this to the correct location.

Terms and Concepts

  • Solar system
  • Light-year
  • Milky Way galaxy
  • Spiral galaxy
  • Jacobus Kapteyn
  • Interstellar dust
  • Harlow Shapley
  • Globular star cluster
  • Spherical distribution
  • Constellation
  • Google Earth

Questions

  • What is a globular star cluster?
  • Why are clusters better than individual stars for creating a 3-dimensional view of our galaxy?
  • How are globular clusters distributed around galaxies?
  • How big is the Milky Way?
  • What is a constellation?

Bibliography

The original data for this project can be found at:

You'll need to download Google Earth to do this science project:

These resources contain good information about astronomy in general and the Milky Way in particular:

Materials and Equipment

  • Personal computer with Internet access and Google Earth installed; see the Experimental Procedure below for more details
  • Lab notebook

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Experimental Procedure

  1. Do your background research so that you are knowledgeable about the terms, concepts, and questions above.
  2. Below is a table listing all of the known globular clusters in the Milky Way
    1. Columns 1-3 are names, or other identifiers, commonly used when to referring to each globular cluster.
    2. Column 4 ("Con") contains the name of the constellation where the globular cluster is found.
    3. The remaining columns are not necessary for this project, but you may find them interesting. Some simple text searches online or an introductory astronomy text book can help you figure out their significance. The abbreviations refer to:
      1. RA, Dec (2000): right ascension and declination for epoch 2000.0
      2. R_Sun, R_gc: distance from our Sun and the Galactic Center in thousands of light years (kly)
      3. m_v: apparent visual magnitude
      4. dim: apparent dimension in arc minutes



 M    NGC/IC  ID/Name/Crossref     Con               RA  (2000)     DEC     R_Sun   R_gc   m_v   dim

104 47 Tuc, Lac I.1 Tucana 00:24:05.2 -72:04:51 14.7 24.1 3.95 50.0 288 H 6.20 Sculptor 00:52:47.5 -26:35:24 28.7 39.1 8.09 13.0 362 Dun 62 Tucana 01:03:14.3 -70:50:54 27.7 30.3 6.40 14.0 Whiting 1 Cetus 02:02:56.8 -03:15:10 1.2 1261 Dun 337 Horologium 03:12:15.3 -55:13:01 53.5 59.4 8.29 6.6 Pal 1 Cepheus 03:33:23.0 +79:34:50 35.6 55.4 13.18 2.8 AM 1, E 1 Horologium 03:55:02.7 -49:36:52 397.6 401.8 15.72 0.5 Eridanus Eridanus 04:24:44.5 -21:11:13 294.2 310.5 14.70 1.0 Pal 2 Auriga 04:46:05.9 +31:22:51 90.0 115.5 13.04 2.2 1851 Dun 508 Columba 05:14:06.3 -40:02:50 39.5 54.5 7.14 12.0 M 79 1904 Lepus 05:24:10.6 -24:31:27 42.1 61.3 7.73 9.6 2298 Dun 578 Puppis 06:48:59.2 -36:00:19 34.9 51.2 9.29 5.0 2419 H 1.218 Lynx 07:38:08.5 +38:52:55 274.6 298.4 10.39 4.6 Koposov 2 Gemini 07:58:17.0 +26:15:18 130 Pyxis Pyxis 09:07:57.8 -37:13:17 129.4 135.9 12.90 4.0 2808 Dun 265 Carina 09:12:02.6 -64:51:47 31.2 36.2 6.20 14.0 E 3 Chamaeleon 09:20:59.3 -77:16:57 14.0 24.8 11.35 10: Pal 3 Sextans 10:05:31.4 +00:04:17 302.3 312.8 14.26 1.6 Segue 1 Leo 10:07:04 +12:47:30 75.0 14.7 4.5 3201 Dun 445 Vela 10:17:36.8 -46:24:40 16.3 29.0 6.75 20.0 Pal 4 Ursa Major 11:29:16.8 +28:58:25 356.2 364.6 14.20 1.3 Koposov 1 Virgo 11:59:18.5 +12:15:36 160 4147 H 1.19 Coma Berenices 12:10:06.2 +18:32:31 62.9 69.5 10.32 4.4 4372 Musca 12:25:45.4 -72:39:33 18.9 23.2 7.24 5.0 Rup 106 Centaurus 12:38:40.2 -51:09:01 69.1 60.3 10.90 2.0 M 68 4590 Hydra 12:39:28.0 -26:44:34 33.3 32.9 7.84 11.0 4833 Lac I.4, Dun 164 Musca 12:59:35.0 -70:52:29 21.2 22.8 6.91 14.0 M 53 5024 Coma Berenices 13:12:55.3 +18:10:09 58.0 59.6 7.61 13.0 5053 H 6.7 Coma Berenices 13:16:27.0 +17:41:53 53.5 55.1 9.47 10.0 5139 Omega Cen, Lac I.5 Centaurus 13:26:45.9 -47:28:37 17.3 20.9 3.68 55.0 M 3 5272 CVn 13:42:11.2 +28:22:32 33.9 39.8 6.19 18.0 5286 Dun 388 Centaurus 13:46:26.5 -51:22:24 35.9 27.4 7.34 11.0 AM 4 Hydra 13:56:21.2 -27:10:04 97.5 83.2 15.90 3.0 5466 H 6.9 Boötes 14:05:27.3 +28:32:04 51.8 52.8 9.04 9.0 5634 H 1.70 Vir 14:29:37.3 -05:58:35 82.2 69.1 9.47 5.5 5694 H 2.196 Hydra 14:39:36.5 -26:32:18 113.2 94.9 10.17 4.3 I4499 Apus 15:00:18.5 -82:12:49 61.6 51.2 9.76 8.0 5824 Lupus 15:03:58.5 -33:04:04 104.4 84.1 9.09 7.4 Pal 5 SerCp 15:16:05.3 -00:06:41 75.7 60.7 11.75 8.0 5897 H 6.8, H 6.19 Libra 15:17:24.5 -21:00:37 40.4 23.8 8.53 11.0 M 5 5904 SerCp 15:18:33.8 +02:04:58 24.5 20.2 5.65 23.0 5927 Dun 389 Lupus 15:28:00.5 -50:40:22 24.8 14.7 8.01 6.0 5946 Norma 15:35:28.5 -50:39:34 34.6 18.9 9.61 3.0 BH 176 Norma 15:39:07.3 -50:03:02 50.9 31.6 14.00 3.0 5986 Dun 552 Lupus 15:46:03.5 -37:47:10 33.9 15.7 7.52 9.6 Lynga 7 Norma 16:11:03.0 -55:18:52 23.5 2.5 Pal 14, AvdB Hercules 16:11:04.9 +14:57:29 241.0 225.0 14.74 2.5 M 80 6093 Scorpius 16:17:02.5 -22:58:30 32.6 12.4 7.33 10.0 M 4 6121 Lac I.9 Scorpius 16:23:35.5 -26:31:31 7.2 19.2 5.63 36.0 6101 Dun 68 Apus 16:25:48.6 -72:12:06 49.9 36.2 9.16 5.0 6144 H 6.10 Scorpius 16:27:14.1 -26:01:29 27.7 8.5 9.01 7.4 6139 Dun 536 Scorpius 16:27:40.4 -38:50:56 32.9 11.7 8.99 8.2 Terzan 3 Scorpius 16:28:40.1 -35:21:13 24.5 7.8 12.00 3.0 M 107 6171 H 6.40 Ophiuchus 16:32:31.9 -13:03:13 20.9 10.8 7.93 13.0 1636-283,ESO452-SC11 Scorpius 16:39:25.5 -28:23:52 25.4 6.5 12.00 1.2 M 13 6205 Hercules 16:41:41.5 +36:27:37 25.1 28.4 5.78 20.0 6229 H 4.50 Hercules 16:46:58.9 +47:31:40 99.1 96.8 9.39 4.5 M 12 6218 Ophiuchus 16:47:14.5 -01:56:52 16.0 14.7 6.70 16.0 FSR 1735, 2MASS-GC03 Ara 16:52:10.6 -47:03:29 29.7 10.4 0.8 6235 H 2.584 Ophiuchus 16:53:25.4 -22:10:38 37.2 13.4 9.97 5.0 M 10 6254 Ophiuchus 16:57:08.9 -04:05:58 14.4 15.0 6.60 20.0 6256 Scorpius 16:59:32.6 -37:07:17 27.4 5.9 11.29 4.1 Pal 15 Ophiuchus 17:00:02.4 -00:32:31 145.5 123.6 14.00 3.0 M 62 6266 Dun 627 Ophiuchus 17:01:12.6 -30:06:44 22.5 5.5 6.45 15.0 M 19 6273 Ophiuchus 17:02:37.7 -26:16:05 28.0 5.2 6.77 17.0 6284 H 6.11 Ophiuchus 17:04:28.8 -24:45:53 49.9 24.8 8.83 6.2 6287 H 2.195 Ophiuchus 17:05:09.4 -22:42:29 30.3 6.8 9.35 4.8 6293 H 6.12 Ophiuchus 17:10:10.4 -26:34:54 28.7 4.6 8.22 8.2 6304 H 1.147 Ophiuchus 17:14:32.5 -29:27:44 19.6 7.2 8.22 8.0 6316 H 1.45 Ophiuchus 17:16:37.4 -28:08:24 35.9 10.4 8.43 5.4 M 92 6341 Hercules 17:17:07.3 +43:08:11 26.7 31.3 6.44 14.0 6325 Ophiuchus 17:17:59.2 -23:45:57 26.1 3.6 10.33 4.1 M 9 6333 Ophiuchus 17:19:11.8 -18:30:59 25.8 5.5 7.72 12.0 6342 H 1.149 Ophiuchus 17:21:10.2 -19:35:14 28.0 5.5 9.66 4.4 6356 H 1.48 Ophiuchus 17:23:35.0 -17:48:47 49.6 24.8 8.25 10.0 6355 H 1.46 Ophiuchus 17:23:58.6 -26:21:13 31.0 5.9 9.14 4.2 6352 Dun 417 Ara 17:25:29.2 -48:25:22 18.6 10.8 7.96 9.0 I1257 Ophiuchus 17:27:08.5 -07:05:35 81.5 58.4 13.10 5.0 Terzan 2, HP 3 Scorpius 17:27:33.4 -30:48:08 28.4 2.9 14.29 0.6 6366 Ophiuchus 17:27:44.3 -05:04:36 11.7 16.3 9.20 13.0 Terzan 4, HP 4 Scorpius 17:30:38.9 -31:35:44 29.7 4.2 16.00 0.7 HP 1, BH 229 Ophiuchus 17:31:05.2 -29:58:54 46.0 19.9 11.59 1.2 6362 Dun 225 Ara 17:31:54.8 -67:02:53 24.8 16.6 7.73 15.0 Liller 1 Scorpius 17:33:24.5 -33:23:20 34.2 8.5 16.77 12.6 6380 Ton 1 Scorpius 17:34:28.0 -39:04:09 34.9 10.4 11.31 3.6 FSR 1767 Scorpius 17:35:43 -36:21:28 4.9 18.6 Terzan 1, HP 2 Scorpius 17:35:47.8 -30:28:11 18.3 8.2 15.90 2.4 Ton 2, Pismis 26 Scorpius 17:36:10.5 -38:33:12 26.4 4.6 12.24 2.2 6388 Dun 457 Scorpius 17:36:17.0 -44:44:06 32.6 10.4 6.72 10.4 M 14 6402 Ophiuchus 17:37:36.1 -03:14:45 30.3 13.4 7.59 11.0 6401 H 1.44 Ophiuchus 17:38:36.9 -23:54:32 34.2 8.8 9.45 4.8 6397 Lac III.11, Dun 366 Ara 17:40:41.3 -53:40:25 7.5 19.6 5.73 31.0 Pal 6 Ophiuchus 17:43:42.2 -26:13:21 19.2 7.2 11.55 1.2 6426 H 2.587 Ophiuchus 17:44:54.7 +03:10:13 67.5 47.6 11.01 4.2 Djorg 1 Scorpius 17:47:28.3 -33:03:56 39.1 13.4 13.60 Terzan 5, Terzan 11 Sagittarius 17:48:04.9 -24:48:45 33.6 7.8 13.85 2.4 6440 H 1.150 Sagittarius 17:48:52.6 -20:21:34 27.4 4.2 9.20 4.4 6441 Dun 557 Scorpius 17:50:12.9 -37:03:04 38.1 12.7 7.15 9.6 Terzan 6, HP 5 Scorpius 17:50:46.4 -31:16:31 31.0 5.2 13.85 1.4 6453 Scorpius 17:50:51.8 -34:35:55 31.3 5.9 10.08 7.6 UKS 1, UKS 1751-241 Sagittarius 17:54:27.2 -24:08:43 27.1 2.6 17.29 2.0 6496 Dun 460 Scorpius 17:59:02.0 -44:15:54 37.5 14.0 8.54 5.6 Terzan 9 Sagittarius 18:01:38.8 -26:50:23 21.2 5.2 16.00 0.2 Djorg 2, E456-SC38 Sagittarius 18:01:49.1 -27:49:33 21.9 4.6 9.90 9.9 6517 H 2.199 Ophiuchus 18:01:50.6 -08:57:32 35.2 14.0 10.23 4.0 Terzan 10 Sagittarius 18:02:57.4 -26:04:00 18.6 7.8 14.90 1.5 6522 H 1.49 Sagittarius 18:03:34.1 -30:02:02 25.4 2.0 8.27 9.4 6535 SerCd 18:03:50.7 -00:17:49 22.2 12.7 10.47 3.4 6528 H 2.200 Sagittarius 18:04:49.6 -30:03:21 25.8 2.0 9.60 5.0 6539 SerCd 18:04:49.8 -07:35:09 27.4 10.1 9.33 7.9 6540 H 2.198, Djorg 3 Sagittarius 18:06:08.6 -27:45:55 12.1 14.4 9.30 1.5 6544 H 2.197 Sagittarius 18:07:20.6 -24:59:51 8.8 17.3 7.77 9.2 6541 Dun 473 Corona Austrina 18:08:02.2 -43:42:20 22.8 7.2 6.30 15.0 2MASS-GC01 Sagittarius 18:08:21.8 -19:49:47 11.7 14.7 3.3 ESO 280-SC06 Ara 18:09:06 -46:25:24 70.7 46.6 1.5 6553 H 4.12 Sagittarius 18:09:15.6 -25:54:28 19.6 7.2 8.06 9.2 2MASS-GC02 Sagittarius 18:09:36.5 -20:46:44 13.0 13.4 1.9 6558 Sagittarius 18:10:18.4 -31:45:49 24.1 3.3 9.26 4.2 I1276 Pal 7 SerCd 18:10:44.2 -07:12:27 17.6 12.1 10.34 8.0 Terzan 12 Sagittarius 18:12:15.8 -22:44:31 15.7 11.1 15.63 1.0 6569 H 2.201, Dun 619 Sagittarius 18:13:38.9 -31:49:35 34.9 9.5 8.55 6.4 AL 3 Sagittarius 18:14:05.7 -28:38:08 1.3 6584 Dun 376 Telescopium 18:18:37.7 -52:12:54 43.7 22.8 8.27 6.6 6624 H 1.50 Sagittarius 18:23:40.5 -30:21:40 25.8 3.9 7.87 8.8 M 28 6626 Lac I.11 Sagittarius 18:24:32.9 -24:52:12 18.3 8.8 6.79 11.2 6638 H 1.51 Sagittarius 18:30:56.2 -25:29:47 31.2 7.5 9.02 7.3 M 69 6637 Lac I.12, Dun 613 Sagittarius 18:31:23.2 -32:20:53 29.7 6.2 7.64 9.8 6642 H 2.205 Sagittarius 18:31:54.3 -23:28:35 27.4 5.5 9.13 5.8 6652 Sagittarius 18:35:45.7 -32:59:25 32.9 9.1 8.62 6.0 M 22 6656 Sagittarius 18:36:24.2 -23:54:12 10.4 16.0 5.10 32.0 Pal 8 Sagittarius 18:41:29.9 -19:49:33 42.1 18.3 11.02 5.2 M 70 6681 Dun 614 Sagittarius 18:43:12.7 -32:17:31 29.4 6.8 7.87 8.0 GLIMPSE-C01 Aquila 18:48:49.7 -01:29:50 10-17 6712 H 1.47 Scutum 18:53:04.3 -08:42:22 22.5 11.4 8.10 9.8 M 54 6715 Dun 624 Sagittarius 18:55:03.3 -30:28:42 87.3 62.6 7.60 12.0 6717 H 3.143, Pal 9 Sagittarius 18:55:06.2 -22:42:03 23.1 7.8 9.28 5.4 6723 Dun 573 Sagittarius 18:59:33.2 -36:37:54 28.4 8.4 7.01 13.0 6749 Berkeley 42 Aquila 19:05:15.3 +01:54:03 25.8 16.3 12.44 4.0 6752 Dun 295 Pavo 19:10:51.8 -59:58:55 13.0 17.0 5.40 29.0 6760 Aquila 19:11:12.1 +01:01:50 24.1 15.7 8.88 9.6 M 56 6779 Lyra 19:16:35.5 +30:11:05 32.9 31.6 8.27 8.8 Terzan 7 Sagittarius 19:17:43.7 -34:39:27 75.7 52.2 12.00 1.2 Pal 10 Sagitta 19:18:02.1 +18:34:18 19.2 20.9 13.22 4.0 Arp 2 Sagittarius 19:28:44.1 -30:21:14 93.3 69.8 12.30 2.3 M 55 6809 Lac I.14, Dun 620 Sagittarius 19:39:59.4 -30:57:44 17.3 12.7 6.32 19.0 Terzan 8 Sagittarius 19:41:45.0 -34:00:01 84.8 62.3 12.40 3.5 Pal 11 Aquila 19:45:14.4 -08:00:26 42.4 25.8 9.80 10.0 M 71 6838 Sagitta 19:53:46.1 +18:46:42 13.0 21.9 8.19 7.2 M 75 6864 Sagittarius 20:06:04.8 -21:55:17 67.5 47.6 8.52 6.8 6934 H 1.103 Delphinus 20:34:11.6 +07:24:15 51.2 41.7 8.83 7.1 M 72 6981 Aquarius 20:53:27.9 -12:32:13 55.4 42.1 9.27 6.6 7006 H 1.52 Delphinus 21:01:29.5 +16:11:15 135.4 126.5 10.56 3.6 M 15 7078 Pegasus 21:29:58.3 +12:10:01 33.6 33.9 6.20 18.0 M 2 7089 Aquarius 21:33:29.3 -00:49:23 37.5 33.9 6.47 16.0 M 30 7099 Capricornus 21:40:22.0 -23:10:45 26.1 23.2 7.19 12.0 Pal 12, Cap Dwarf Capricornus 21:46:38.8 -21:15:03 62.3 51.9 11.99 2.9 Pal 13 Pegasus 23:06:44.4 +12:46:19 84.1 87.0 13.80 0.7 7492 H 3.558 Aquarius 23:08:26.7 -15:36:41 84.1 81.2 11.29 4.2


Table 1: List of all known globular clusters in the Milky Way. This table is reproduced from data available as of June 30, 2010 at http://seds.org/messier/xtra/supp/mw_gc.html#harris. See Bibliography.



  1. Count how many globular clusters are in each constellation.
    1. NGC104 is the first globular cluster in the list. It is seen in the constellation Tucana.
    2. Make a data table in your lab notebook, add the constellation Tucana, and put NGC104 next to it.
    3. Repeat the process for each globular cluster. Add a new line in your data table for each constellation, but if a cluster is in a constellation that you already have in your list, put the cluster's name on that line instead of on a new one.
    4. Count the number of globular clusters you found in each constellation and record the numbers in another column in your data table. Note: Every entry in the data table is a globular cluster—some begin with "M," but most are names, numbers or codes. With a little patience you can easily sort all of the entries by constellation.
  2. Identify the three constellations with the most globular clusters seen in them.
  3. Now go to http://earth.google.com and click "Download Google Earth."
    1. Click "Agree and Download."
    2. Once the file has been downloaded, install the program.
    3. Open the Google Earth program.
  4. Set up Google Earth in Sky Mode.
    1. At the top, click "View," then "Explore," then select "Sky."
    2. On the left-hand side of the window, you should see "Layers."
    3. Uncheck every item, except "Imagery" and "Backyard Astronomy."
    4. Click the arrow next to "Backyard Astronomy."
    5. Uncheck every item except "Constellations."
  5. Try to become familiar with the Google Earth navigation controls by panning around and zooming in and out, using the controls located in the top right corner of the screen.
  6. Notice the bright band that stretches across the sky. This is the disk of our Milky Way galaxy!
  7. Find the three constellations that contain the most globular clusters, which you identified in step 4.
    1. On the left-hand side is a search bar; type in the name of the first constellation.
    2. Repeat for the other two constellations.
    3. Zoom out and pan the sky until you can see all three constellations at once.
  8. Are the three constellations near each other? Most of the Milky Way's globular clusters should be in the direction of the center of the galaxy. Where do you think the center of the galaxy is?
  9. In the search bar, type "Galactic Center" to find the true center of the galaxy. How close was your guess?
  10. Try going back and using three other constellations with fewer globular clusters to predict the center of the galaxy. Is this second prediction more or less accurate (meaning closer or farther away from the true center of the galaxy) than the first one? Based on your results, do you think the distribution of stars really does increase as you approach the center of the galaxy?
    1. For your project display board, you can create a table or graph showing how the accuracy of your prediction changed as you used sets of constellations with fewer and fewer globular clusters to create those predictions.

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.


Variations

  • Find the distribution of globular clusters in the Milky Way by plotting their locations using Google Earth.

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Ask an Expert

The Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Ask an Expert

Related Links

If you like this project, you might enjoy exploring these related careers:

Cartographer studying image data

Cartographer or Photogrammetrist

Maps can give us much more information than ways to get from A to B. Maps can give us topographic, climate, and even political information. Cartographers and photogrammetrists collect a vast amount of data, such as aerial data and survey data to produce accurate maps and models. For example, by collecting rainfall data, a cartographer can make an accurate model of how rainfall can affect an area's watershed. The maps and models can then be used by policy makers to make informed decisions. Read more
NASA astronomer

Astronomer

Astronomers think big! They want to understand the entire universe—the nature of the Sun, Moon, planets, stars, galaxies, and everything in between. An astronomer's work can be pure science—gathering and analyzing data from instruments and creating theories about the nature of cosmic objects—or the work can be applied to practical problems in space flight and navigation, or satellite communications. Read more

Looking for more science fun?

Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.

Find an Activity