For all of you southerners (people who live in the southern hemisphere), this is a sight that you might recognise when looking towards the night sky. Can you guess what these white blips are? There are actually three objects in this image that you can see, one on the left and two on the right. Truth be told, there are actually three on the right, but the third isn’t visible unless you’re looking at the original 73mb image (which you are not). So what do you think we are looking at here?
The Large Magellanic Cloud:
Starting on the left we have the Large Magellanic Cloud (LMC). At a distance of 165,000 light years, it is outside of our galaxy. It isn’t surprising to note then that the LMC is not just some random, slowly moving cloud in the clear skies-- it is a dwarf galaxy. Unlike most other galaxies that we might see in the sky, it doesn’t have a well defined structure. Moreover, it is close enough to the Milky Way that it is being gravitationally distorted, effectively being pulled in. The LMC will inevitably become a part of the Milky Way.
The Small Magellanic Cloud:
Moving onto the right side of the image, the smaller cloud is called the Small Magellanic Cloud (SMC). Coincidence? I think not! The SMC is a little farther out at a distance of 210,000 light years. So close (by cosmic standards) but yet so far (by our Earthly standards). It is the farthest away of the nearby galaxies; it is also the smallest and most disrupted. The SMC has the characteristics of being a galaxy that has been greatly affected by other nearby galaxies, interactions between the Milky Way and the LMC, both of which are more massive objects that are tugging at it.
The third visible object in this image is just a fraction to the right of the SMC, it appears as a large very bright star. This is 47 Tucanae (NGC 104), one of the Milky Way’s larger globular clusters, not the largest but it’s up there. This globular cluster lies at a distance of 15,000 light years, much closer than the SMC and LMC. It is visible with the naked eye in under very dark skies.
The forth object in this image, one that you cannot see, is another globular cluster, NGC 362. This cluster virtually lies in front of the SMC visually, realistically, it is at a distance of 25,700 light years. NGC 362 is typically overlooked, vastly overshadowed by the bigger and grander 47 Tucanae.
Lastly, I thought it would be prudent to give some background on the image itself. This was taken with a Nikon DSLR, a 50mm f/4 lens with a 10 second exposure. The yellowish brightness at the bottom of the image is light from a major city from 130km (80 miles) away. The glow of the city's sodium vapour lamps (many street lights) is the bane of all astronomers' existence. For many of us, astrophotography isn’t accessible with a telescope. This can be due to price, portability or even both. Armed with just a digital camera and a tripod, amazing images of the night sky can be taken, some truly breath taking.
People such as Mike Salway (click the link to see his work) have brought the beauty of the skies down to an observable level, in a way that the Hubble Space Telescope never has. On a clear night, look up into the skies and look, see what you can find. The Large and Small Magellanic Clouds are two beautiful sights for the southern hemisphere. Anyone with a digital camera capable of timed exposure and a tripod can image the skies, give it a try and see what you can achieve.