Life Among the Stars

We are now in August, the best month of the year for looking at and photographing the cloudy core of the Milky Way, the galaxy that is home to our Sun and 200 billion other stars. I find photographing this vast cloud of other stars and worlds an extremely humbling experience, especially when you consider that this single galaxy may contain 300 million potentially habitable planets and that there are a total of 170 billion other galaxies in the Universe as a whole. With mind-blowing numbers like these, we surely must consider the possibility of there being life beyond Earth.

At this time of the year, the sun sets at around 9:00 pm and the stars and the constellations become visible from about 10:00 pm onwards. So, if you spend some time outside around then and look south, you’ll see the core of the Milky Way beginning to appear in the lower part of the sky. Having risen above the horizon in the southeast at about 7:00 pm, this cloudy mass of dust and stars will have travelled upwards and westwards to become visible as twilight ends. At this point, it reaches its highest point in the night sky and begins to drop down towards the horizon while it continues westward. It will eventually set around midnight, giving a period of about two hours during which it can photographed in all its glory. I was pleased to be able to do this when I captured the image below on a beautifully still and clear night from the Ardtoe Jetty in Kentra Bay.

When out under the night sky capturing images like this, you are looking up and seeing around 6000 stars with your naked eye.  I find that this really does give you a sense of how insignificant both we and our planet are in the grand scheme of things, especially when you consider that for every star we can see, there are over 30 million more in our galaxy that we cannot. These 200 billion stars, both seen and unseen, make our Milky Way an averaged sized galaxy, while the largest galaxy we know is designated IC 1101 and has over 100 trillion stars.

In fact, a vast number of galaxies exist and counting them may seem like an impossible task, but it is something that astronomers have tried to do with the Hubble Space Telescope. They used it to photograph a small patch of sky in repeat visits for a total of 50 days during 2003 and 2004 and the information was used to compile an eXtreme Deep Field (XDF) image of it. The XDF revealed thousands of galaxies, both nearby and very distant, and from this they estimated the number of galaxies in the rest of the sky to be 170 billion.

Still Under the Stars - Kentra Bay, Gobshealach, Ardnamurchan
There was not a breath of wind on this night under the stars, so the boats moored up in Kentra Bay sat perfectly still under the Milky Way while a bright red Mars, low on the horizon, was reflected in the water

​With each of these 170 billion galaxies containing an average of 200 billion stars, and with the current consensus among astronomers being that there should be at least as many planets as there are stars, it can be estimated that there are at least 34 sextillion (34,000,000,000,000,000,000,000) planets in the universe.
 
This is an incomprehensibly large number of planets, and it does make you wonder if there is indeed life out there beyond Earth. Indeed, to date, astronomers have found 55 planets that are orbiting the habitable zones of stars and by extrapolating this to the number of stars in the Milky Way they estimate that there could be 300 million such planets in our galaxy alone.
 
So, with this in mind, why don’t you go outside after dark on a clear August night and look south to see the cloudy core of the Milky Way, consider that someone may be looking back at you and remember this quote by Carl Sagan, the renowned astronomer and astrophysicist:
 
“The universe is a pretty big place. If it's just us, seems like an awful waste of space.”

Life Beyond the Bothy III - Camas Chil Mhalieu, Kilmalieu, Ardgour
When standing looking at the vastness of the night sky that lay beyond this small bothy, I couldn’t help but think about the probability of there being life beyond Earth