Astronomy at Low Frequencies

From Outback Western Australia

We just finished a short video introduction to a new radio array being built in Western Australia called the Murchison Widefield Array. This new radio telescope array is sensitive to frequencies between 80 and 300 MHz (or, in wavelength terms, 1-4 meters), and one of its main science goals is to explore a time in cosmic history called the Epoch of Reionization. It occurred more than 13 billion years ago, when the first stars were beginning to shine out and the first shreds of galaxies were forming. The array will also probe solar and heliospheric events, as well as transient events that occur all over the sky in those wavelength ranges.

Most of the signals in the wavelength range the MWA is sensitive to are masked or covered up by broadcast and other signals that humans use for telecommunications. This makes it very difficult to catch the signals from distant events and objects in space.

In order to catch the signals they want to study, the MWA’s planners chose a location in one of the most radio-quiet places on Earth: Western Australia. The population density there is practically zero when compared to more populated areas, and there’s just not a lot of radio frequency interference to disturb the signals MWA is designed to get.

Scientists in the U.S., Australia, and India are already working with the array, even as it’s being built. The video, which is called MWA: From the Outback to the Cosmos, shows you where the array is and what they hope to do with it. You can also read more about the array at the link at the top of this story.

Looking Up Enriches Your Brain

Kepler Said So

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I was digging around online the other night for some information and ran across a quote that you might find refreshing. It’s by astronomer Johannes Kepler, and it goes like this:

The treasures hidden in the heavens are so rich that the human mind shall never be lacking in fresh nourishment.

Well, think about it for a minute.

If you step outside on a clear night and look up, what’s the first thing you see?  If the Moon’s out, of course you see that.  And, if you gaze it at for more than a few seconds, you start thinking about what it’s made of. Or, you might think back to a time when men walked on it.  If you have a telescope, you probably decide to go get it and check out the Moon, up close and personal.

If the Moon’s not out, then you have the stars and planets to gaze on. And those also stimulate ideas and questions in your mind.  That’s the nourishment Kepler is talking about. Mind nourishment, stimulated by stars, takes you out to the universe. It gives you a reason to look beyond yourself, away from the planet and out to places where other suns (and other planets) are whirling around in the galaxy just as ours does.  And that is a great treasure to think about!  More precious than all the wealth on this planet, and free to anyone who can look up and wonder about the sky!