Beyond the visible
Modern astronomy techniques also allow astronomers to see what the human eye cannot. Radio,
X-ray and infrared telescopes detect electromagnetic emissions that are invisible to the naked eye, but a watershed to astronomers studying stars and other celestial objects.
"When you talk about X-ray astronomy, you're automatically talking about space telescopes," Beletic said. "The Earth's atmosphere absorbs that radiation, thankfully for us, so you wouldn't ever be able to see it from the ground."
The Chandra Observatory, the European XMM-Newton satellite, and a pair of other space-based X-ray tools allow scientists to search for signals from around neutron stars and black holes, as well look for the dark matter thought to make up most of the universe.
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| Galileo Galilei discovered four moons (Io, Europa, Ganymede and Callisto) circling Jupiter in 1610 with a telescope he built himself. Galileo's homespun astronomy observations also included the Moon, Venus, and helped show that the Earth and other planets revolved around the Sun, and not the other way around. Click to enlarge.
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| One of the foremost astronomers of the 20th Century, Edwin Hubble lived from 1889 to 1953 and is shown above posing with the 48-inch telescope on Palomar Mountain and his famous pipe. Hubble's hands-on research helped determine existence of other galaxies, as well as the universe's expansion. The Hubble Space Telescope is named after him. Click to enlarge.
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| Charge Coupled Devices (CCDs), like this one made for one of the telescopes at the W.M. Keck Observatory, serve are the go-to tool for modern astrononical observation. Click to enlarge.
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| The laser light that creates the virtual star is seen emanating from a device attached to the Keck II telescope.
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|  | TODAY'S DISCUSSION | | |
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While X-rays have higher wavelengths than the light seen by the human eye, infrared radiation and radio waves are below the visible spectrum. Using
infrared detectors, astronomers study objects too cool to emit visible light signals. They can also use infrared to see through dust and gas clouds to observe areas like the center of the Milky Way or stellar nurseries. Radio astronomy, on the other hand, is key for detecting exotic things like pulsars, quasars and the universe's background radiation.
Astronomers can even couple the observations from several telescopes, a process known as
interferometry, to better resolve distant objects and determine their sizes and diameters.
"We can see fainter objects, we can see more details and we can do it faster," Thompson said. "And that's why astronomy is such a rich field these days, because of technology."
But some researchers feel modern technology has removed the personal touch from the science that only direct observations can provide, despite its superior ability to collect data. The human eye is only 1 percent as effective at collecting light as an electronic detector, and even then it can only take observations for about a 30th of a second. CCDs and other detectors can take in observations over long hours to put together a single image of a nebula or star.
Data mining
Astronomers have even found a way to make discoveries without making observations. The sheer amount of data collected by the Hubble Space Telescope and other instruments has made data-mining a viable pastime for many astronomers unable to make direct observations.
Virtual astronomy is the act of sifting through past observations to make new discoveries. A "virtual observatory" -- basically a computer database of observations -- in Europe helped astronomers refine the size of a space rock known as 2001 KX76, and a number of such "observatories" are under development in Europe, Australia and in the United States.
"It's all changed so much," Beletic says of his craft. "But basically, what it comes down to is trying to get information any way you can."
But if Galileo were here, modern astronomers say, he might feel overwhelmed at the mechanization of astronomy and nostalgic for a more hands-on approach.
There are mixed feelings among astronomers on whether the spirit behind the science has been lost in the push for bigger and better machines. While Thompson has no qualms with seeing space through a computer screen, actually looking through a telescope, he said, is important for students in the field, who need direct experience to grasp what they are studying.
But for Beletic and others, the romance of the stars, like the occasional need to peer through an eyepiece, is too strong to ignore.
"One of the best experiences in my life was on an observation at the 2.4-meter telescope on Kitt Peak," Beletic said of an observatory near Tucson, Arizona. "The team finished observing all their targets, and at five in the morning we packed everything up and just used the telescope to look at the Moon. It was fantastic, like you were flying right over it…that was a wonderful experience."
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%20circling%20Jupiter%20in%201610%20with%20a%20telescope%20he%20built%20himself.%20Galileo's%20homespun%20astronomy%20observations%20also%20included%20the%20Moon,%20Venus,%20and%20helped%20show%20that%20the%20Earth%20and%20other%20planets%20revolved%20around%20the%20Sun,%20and%20not%20the%20other%20way%20around.%20Click%20to%20enlarge.)
,%20like%20this%20one%20made%20for%20one%20of%20the%20telescopes%20at%20the%20W.M.%20Keck%20Observatory,%20serve%20are%20the%20go-to%20tool%20for%20modern%20astrononical%20observation.%20Click%20to%20enlarge.)
