The 3rd in Don Kurtz’s excellent series of lectures moved outwards, towards the edge of the universe. While the first was a brief romp through the history of astronomy, and the second focused on the wonders of our nearest star, the 3rd looked outward towards the stars and beyond.
There’s $600 million spent on each space shuttle launch, and a recent mission focused on the Hubble telescope. A relatively small telescope in size, but, situated in space, it has a clear view out into the universe, unhindered by our ever-smoggier atmosphere. Our eyes are relatively limited in the range of light we can see – there’s infra-red (heat) on one side, and ultra-violet on the other. The Hubble telescope can detect infra-red light, and there are some amazing pictures being sent back.
It’s currently thought that when the universe formed, only Hydrogen and Helium elements existed. Other elements are cooked up in nuclear reactions in stars, and flung out across the universe. So, in a very real sense, we are star-born, and couldn’t exist otherwise. Certain, very rare, elements, are only created when a star goes supernova – platinum and gold.
The Hubble telescope is returning the most phenomenal pictures – galaxies lit up as a star goes nova, emitting light, and, year by year, as the light travels a light year further out, the galaxy lights up revealing more of its secrets. Stars that are revealed to be entire galaxies, and again stars in these that appear to be galaxies, as we look deeper and deeper in space.
The latest telescope can see galaxies 13 billion light years away, believed to be close to the very edge of the universe. The next generation will see beyond this, and, if galaxies are seen even further out, the model of the universe’s expansion as currently understood will have to be rewritten.
At the same time, Kurtz is part of a team looking for earth-like planets. He said that he couldn’t reveal anything yet as he has signed a non-disclosure agreement, but, in a future year will return with the findings. The method is simple, but wasn’t possible without the latest high-powered telescopes. Look for a star similar to the sun. Look for planets crossing its face, and see when they return again. An earth year later, and about the same size, and you’ve got an earth-like planet.
Looking into space is looking into the past – what we see is what existed at various points in the past. Galaxies could have collided, stars could have gone supernova – we wouldn’t see it until its light gets here. When we look at the nearest star besides the sun, we’re looking 4 and half years into the past. When we look into deep space, we’re looking 13 billion years into the past. Space-time indeed.
To end off the series, here are some videos.
Images from Hubble
Images from Hubble 2
Hubble Deep Space