earthbound telescopes can see as far as Hubble can. All telescopes
are essentially "time machines." Probing the secrets
of "deep" space means looking farther back in time.
That's because light from faraway galaxies takes millions
to billions of years to reach Earth, providing astronomers
with a record of how those objects appeared long ago. But
the "eye" in space has sharper vision because of
its super location. At 353 miles (569 kilometers) above our
planet, the orbiting observatory is outside Earth's turbulent
blanket of air that makes star images wiggle.
can snap those sharper images while moving. Unlike terrestrial
observatories, which are perched on mountain tops, Hubble
doesn't stay put. It whirls around Earth every 97 minutes
at 17,500 mph (28,163 kph). The telescope has no rocket motor:
it is in orbit around Earth and runs on sunlight. Hubble also
does what it's told. Earthbound computers send detailed instructions,
telling it where to point and which cameras to use.
orbiting observatories have probed the secrets of space, but
Hubble is the largest and most versatile. Its visible-light
camera called the Wide Field and Planetary Camera 2
has consistently delivered stunning images of celestial
objects, including the pillars of dust and gas that harbor
nascent stars and the colorful death shrouds of aging, Sun-like
the visible-light camera may be Hubble's "bread and butter"
instrument, it's by no means the telescope's only source of
celestial revenue. Hubble has a fleet of other science instruments
that covers a broad range of light, from ultraviolet to near
infrared. These instruments allow Hubble to probe a galaxy's
hottest stars and to peer far across space to study the evolution
of galaxies. With Hubble's help, astronomers have monitored
weather patterns on our solar system planets and harvested
important information about stars and galaxies.
BACK | NEXT
search & index | about
us | contact us | copyright