Hubble Sets New Distance Record With Discovery of Ancient Galaxy

Yesterday I mused about the implications of NASA's existence. If you missed it, check it out.

Today, as if to justify my position, I present to you an impressive result from the world's most famous telescope. But before we get to that, I feel compelled to tell you why we care.

The Universe is a mighty big place; larger than you or I can possibly fathom. This, naturally, makes it extremely difficult to study. More troubling still is the time scale over which astronomical systems evolve.

Most stars take billions of years to mature. Our Sun, for instance, at roughly five billions years is middle-aged. The life times of galaxies? Significantly longer yet.

So if it were your job to study such things, your task might appear hopeless. But is it?

An illustration I use in my introductory astronomy course goes sometime like this: Suppose that we were visited by an alien race whose biology was completely dissimilar to ours in every way. They would be inherently curious about every facet our existence. But now let's presume that, weirdly, they are only allowed to stay on our planet for one hour and they are only allowed to watch.

This is surely not long enough to fully observe the course of human life. Many humans approach 100 years of life, some more. How could these aliens possibly begin to grasp the nature of mankind in such a short amount of time?

You may already have realized the answer. They can't, at least not by studying a single individual. But by studying the whole of humanity, even a snapshot of our lives would be enough to infer what life is like here on Earth.

They would see infants, toddlers, teenagers (God forbid), young adults, middle aged persons and finally those in the later stages of life. From these brief observations of many people in many settings, much could be learned about how we grow from babies to adults, how we form relationships and what we hold most dear.

Our visitors would learn much about our strengths and our weaknesses, how we interact with other humans, and how we treat nature and animals. And most of all, they would learn what governs our existence.

Scientists are faced with a similar plight when studying the Universe. We get but only a snapshot of stars, planets, nebulae and galaxies. But from this we can learn so much.

By seeing these objects at various stages of their evolution we can discern how stars are born and how they die. We can predict the existence of things like black holes and neutron stars, then go looking for them. All of this is possible simply by observing the Universe around us.

But what if we wanted to take things a step further? What if we desired to see the oldest galaxies in the Universe being born? We can.

How do we do it? By using mother nature's time machine. It may sound like science fiction, but it is actually a consequence of how light moves through the Universe.

Photons, or packets of light, are limited to the cosmic speed limit of 299,792,458 meters per second. That is fast enough to circle the Earth 7.5 times every second.

It's fast, but even at those speeds the Universe is so big that it still takes billions of years to cross it. As a result, light that left the first galaxies is just now arriving to us, billions of light-years (the distance light travels in one year) away. So as we peer deeper and deeper into space, we are effectively looking back in time to the Universe at it appeared at the very beginning.

Of course, seeing these objects is very difficult. They are so far away that they appear very, very dim. So even our most powerful telescopes have to stare at them for an incredibly long time in order to detect them.

A year of observations and detailed analysis of data taken with Hubble's Wide Field Camera 3 (installed in May, 2009), was needed to resolve what researchers say is a mini-galaxy, about 1/100th the size of our Milky Way. It formed merely 480 million years after the Universe sprang into existence, some 13.2 billion years ago.

It is observations like these that are going to allow scientists to identify when the first stars sprang into existence in the early Universe. And, perhaps, how the Universe formed in the first place.

Image Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), R. Bouwens (University of California, Santa Cruz and Leiden University), and the HUDF09 Team