I am a big fan of the Hubble Space Telescope. The telescope has led humanity to some amazing discoveries. There are differences of opinion about which are the telescope’s most important discoveries, but for my money, I vote for the Hubble Deep Field and Hubble Ultra-Deep Field photographs. I find that many people are unfamiliar with the Hubble Deep Field photographs. Here is my attempt to bring the explanation of the Hubble Deep Field photograph down to something the astronomy novice can begin to truly appreciate. Without a doubt, the information presented is humbling. (For you astronomy buffs, this explanation is quite simplistic).

First, some basic scientific facts to help you understand the massive, unimaginable distances we are discussing here…

Light is not instantaneous. Light travels through the Universe at a constant speed. The speed with which light travels is 186,000 miles per second. To put that in perspective, if you were on planet Earth, and were to shine a light into Outer Space for a duration of one second, in that one second period of time, that light would be visible from 186,000 miles away from planet Earth! The moon averages about 239,000 miles from Earth, so the light would reach the moon in about 1 1/4 seconds.

Distances in space are so unimaginably vast, that distances are measured by the distance light will travel in one year (186,000 miles per second x 60 seconds x 60 minutes x 24 hours x 365.25 days per year, which is 5,878,499,814,186.5 miles (Five Trillion, 878 Billion, 499 Million, 814 Thousand, 186.5 Miles) travelled in one year. Therefore, 1 Light Year is equal to 5,878,499,814,186.5 (Five Trillion, 878 Billion, 499 Million, 814 Thousand, 186.5) miles.

Our solar system, which consists of the Sun and 9 planets (including Pluto, for the sake of this example) is a total of 10 light HOURS in diameter, or 186,000 miles x 60 seconds x 60 minutes x 10 = 6,696,000,000 (6 Billion, 696 Million) miles across.

The star closest to Planet Earth (other than our own Sun) is Alpha Centauri, which is roughly 4.7 light years from Earth, or 186,000 x 60 seconds x 60 minutes x 24 hours x 365.25 days x 4.7 Years = 27,587,653,920,000 (27 Trillion, 587 Billion, 653 Million, 920 Thousand) miles from Earth.

Our Solar System resides within the Milky Way Galaxy. A Galaxy is (simplistically) a collection of Sun like stars. Our Milky Way Galaxy contains around 400,000,000,000 (400 Billion) stars. Many of those 400 Billion stars have the potential for planetary objects rotating around them.

With those facts as background…

For the Hubble Deep Field photograph, scientists selected an extremely tiny section of blank sky where few observable objects existed, and then pointed the Hubble Space Telescope at it for a total of 10 full days. During that 10 day period of time, the telescope simply stared at that blank section of sky, gathering every available photon of light projected to it from that tiny patch of dark sky. (The tiny patch of sky they looked at was 1 / 12.700,000 of the sky – an unbelievably tiny patch of sky).

The result? The first time they tried this (the Hubble Deep Field photograph), they found roughly 3,000 galaxies inside that extremely tiny tiny section of sky residing at the far reaches of the Universe, with each of the pictured galaxies potentially containing as many stars as are in our Milky Way.

The second time they tried this (the Hubble Ultra Deep Field photograph) with improved instrumentation pointing at another extremely tiny section of blank sky, they found as many as 10,000 galaxies in that tiny section of sky! Each of the 10,000 pictured galaxies may have as many stars as our own galaxy (about 400 Billion stars), and many of those stars has the potential for orbiting planets like our own.

(The light from the pictured galaxies left those galaxies as many as 13 Billion Years ago. The light from these galaxies [galaxies similar to the Milky Way galaxy we reside in] has been travelling through the Universe at 186,000 miles per second for as many as 13 Billion Years before the light finally reached the Hubble Space Telescope. That gives you a perspective of how unimaginably far away the pictured galaxies are. In addition, since those are just the galaxies visible in this extremely tiny section of sky, try to grasp what must exist in the unimaginable immenseness of space that remains yet unpictured).

Recent estimates are that the Universe contains 100,000,000,000 (100 Billion) galaxies, some with more stars than our Milky Way, some with fewer stars. If we were to calculate that out, we may be able to estimate that the Universe contains 100,000,000,000 (100 Billion) galaxies x 400,000,000,000 (400 Billion) stars in each galaxy, for a total of 40,000,000,000,000,000,000,000 (40 Sextillion) stars. Many of those stars may have 1 or more planets orbiting around it. The chances that our star (the Sun) harbors the only planet in the entire Universe that has developed some form of life seems extremely unlikely.

Although no one really knows for sure, recent estimates have said that the known Universe is 47,000,000,000 (47 Billion) light years across (in other words, it would take a beam of light travelling at 186.000 miles per second 47 Billion years to travel from one side of the Universe to the other side. Calculated in miles, the distance is so big that the number of miles travelled is really incomprehensible. (5,878,499,814,186.5 (Five Trillion, 878 Billion, 499 Million, 814 Thousand, 186.5) miles x 47,000,000,000 (47 Billion) light years).

If you’re a non-scientist who has made it this far, congratulate yourself. The Hubble Deep Field photographs have shown us that the Universe is far more than immense. The Universe is immense far beyond our ability to comprehend its size. The potential for Earth like planets (with life) elsewhere in the Universe is significant. We are more than microscopically small in comparison to the whole.

If I’ve done an effective job with my explanation, you will hopefully come away with some sense of the Awe, Wonder, Majesty, and Humility that many people feel when they grasp the implications of this research. Could something this massive with life that has evolved at least on planet Earth have been the result of some type of cosmic accident, or is it evidence of something more divine?  What’s your explanation?

Something to think about…..

Three brief, excellent and extremely understandable videos that describe the Hubble Deep Field experiments are shown below.  Below that, you will find additional Hubble telescope links.  Enjoy.