Reprinted From Genesee Sun
|An Evening with the Stars|
News Editor/ Jeff Shappard
The 'Heavens Above' exhibit at SUNY Geneseo held its Grand Opening Celebration last Friday night at Milne Library to the delight and wonderment of the 150 or more people in attendance.
Dr. Matthew Bobrowsky, an Astronomer at the Space Telescope Institute in Baltimore MD, was the guest speaker of the event, followed by a viewing of about 20 Hubble Space Telescope images on display. While occasionally asking for participation from the crowd, he educated the audience and encouraged their curiosity.
Dr. Bobrowsky explained that there are several reasons for having a telescope in space, but the main purpose for it being placed there is that only certain types of radiation make it through the atmosphere of the Earth to observatories on the ground. Dr. Bobrowsky said, "Visible light and radio waves are the only two types of radiation which get through the Earth's atmosphere." Additionally, Hubble can rotate in all directions to view the Universe because the Earth is not 'underneath' it and scientists do not have to make allowances for sunlight, clouds, and storms.
The Hubble Space Telescope (HST) travels at more than 17 thousand mph and completes its trip around our planet once every 97 minutes. Because of Hubble's position and power of magnification, it can capture images of stars, planets and galaxies as far away as 13 billion light years. Perhaps the most amazing aspect of the apparatus is its ability to hold itself steady while taking images of far, distant objects. In order to capture a clean, viewable image from something as far away as 13 billion light years, (a light year being the distance light travels in a year,) Hubble has to first focus on the distant star, then keep the lens in that exact position until enough light radiation from that star reaches it, allowing the stars or galaxies to be seen.
Imagine focusing a laser pen on a penny attached to the wall about 40 feet from you. If you try this, one can see how the laser light shakes and shimmies with each subtle movement of the hand. Hubble performs this task using multiple computers, but at a mind-boggling distance and for relatively long periods of time.
According to Dr. Bobrowsky, the greater the distance into space one looks trough a telescopic lens, the farther back into time one is seeing. A telescope might make an image bigger, but it still takes just as long for the light to reach the lens from that distant star.
Although it does not seem like any time elapses when one turns on a light in the kitchen, it's only because the distance from the light in a ceiling panel to the observer's eye is infinitesimally tiny compared to the staggering vastness of Space. Given that light travels (in a vacuum like space) at 186,282.397 miles per second, it takes about 1.2 seconds for a ray of light to travel from the Earth to our Moon, more than 2 million miles away. The time lapse between when the light is emitted from a star and its' being noticed by an instrument such as a telescope varies directly with distance. So, it takes 13 billion years for light from the most distant stars to reach us but in the meantime, that star may very well have burned out, collided with another object, or exploded altogether!
Following this mindboggling and vastly enormous presentation, the audience retired to the Library for cookies and a view of the many Hubble images on display.