Hubble Releases A Magnificent Image

At first glance, the image looks like a swarm of iridescent killer bees hovering around their hive. Then it appears as an exploding Christmas tree whose bulbs scatter forth in all directions. But what is it, actually? This is a picture of the "Frontier Field." It was taken with the Hubble Space Telescope and released by the NASA space program, in honor of the 50th anniversary of Star Trek. Remember the Final Frontier? 

The Hubble Space Telescope (HST) is a high powered gadget that was supposed to launch back in 1983, but technical and financial difficulties, including the Challenger Disaster of 1986, derailed the Hubble development process for a while. So the Hubble was first launched in 1990, and the Hubble telescope remains in use today. From its original estimated cost of around 400 million, it ended up costing 2.5 billion dollars just to construct the HST.

The Hubble Space Telescope was named after astronomer Edwin Hubble. The Hubble telescope, with miraculously high resolution due partly to its placement outside the earth's atmosphere, has taken some of the most detailed visual light images ever seen in the earth's night sky and beyond.

In this image, the Hubble telescope is peering through clusters of galaxies to the very edge of the observable universe. The frontier field is a region of sky no bigger (to us) than a dollar coin being viewed at a distance of sixty feet. However, the region of sky known as the frontier field is more than 4 billion light years away. In that region, the Hubble telescope sees hundreds of galaxies. While any galaxy cluster would be an exciting enough discovery, this one allows the Hubble Space telescope to see through it to the galaxy clusters beyond. That's what those streaks of light represent. They are an optical illusion of further away galaxy clusters, warped by gravitational lensing.

Gravitational lensing is an effect of General Relativity explained and mathematically proven by Albert Einstein. He maintained that massive objects, like stars or galaxies, will bend light around them, like a lens. How much the light bends depends upon the mass of the object, and so it is possible to determine the mass of an object in terms of the light that bends around it.

This reveals (or is supposed to reveal to those of us who understand it) that the universe is mostly invisible.

Huh?

Yes, invisible. In other words, the galaxies are made up of mostly dark matter. Gravitational lensing allows us to map the dark matter.

Because light is so fast and so continuous, it is easy to forget that light takes time to reach us. For example, if a star is 100 light years away, and you look up and see that star, you are looking at the light that left that star a hundred years ago. In other words, we see stars as they were, not as they are. Not that much has changed over the past few hundred million years.

After all, what's one little eon in the life of a star?