Just a few hundred miles in space, above the cloudy blanket of the atmosphere a magnificent telescope orbits the Earth. It is looking at our nearest neighbors and deep into the far reaches of space helping uncover the deepest mysteries of the galaxy.
The Hubble Space Telescope is a satellite telescope located 370 miles (600 km) above the Earthís surface. Since it is located in space, the Hubble can look into space without the effects of Earthís atmosphere. This allows it to get clearer pictures and collect better information about things in space.
The Hubble is a telescope, but it is also a spacecraft designed to operate in space. It has its own power supply, communications equipment, and control system. It orbits Earth once every 97 minutes.
Questions to Answer
The space shuttle Discovery brought the Hubble Space Telescope into space in 1990 to find the answer to these questions:
How It Works
The Hubble works on the same principle as the first reflecting telescope built in the 1600ís by Isaac Newton. Light from the first mirror is reflected to a smaller second mirror and then back through a hole in the first mirror to instruments. The instruments send the information back to Earth by computer. There are no computer cords running from the Hubble Space Telescope to the Earth! Instead, information is sent using radio waves.
The $8 Million Mistake
Two months after the Hubble Space Telescope was launched, it was in big trouble. The pictures it sent back were fuzzy and out of focus. Many people said it was ruined and couldnít be fixed. Almost right away NASA and the European Space Agency got to work fixing it.
When the Hubble was first launched its lens was off by 1/50 of a human hair. Focusing on small dark images was very difficult because of that small defect. Finally a solution was found. NASA sent a shuttle on a mission to fix the Hubble. Since the Hubble is so low in the Earthís atmosphere, it can be worked on in space. The cost of repairing the mirror cost NASA $8,000,000 dollars. It will continue to be worked on about every three years, until 2010 when it will be retrieved.
What the Hubble Found
With the Hubble Telescope, people have been able to find and learn many things. It has increased the chance of finding other living things out in space that are more advanced than us. The Hubble has sent back amazing pictures of star birth in the Cartwheel Galaxy.
With the Hubble, the Space Telescope Science Institute was able to measure the speed of gas rotating around a suspected black hole in the middle of a far away galaxy. Scientists hoped since the Hubble orbits above the Earth and its atmosphere, it would be able to capture light from about twenty billion years ago.
The Hubble Space Telescope has observed all the planets except Mercury and Earth. It doesnít observe Mercury because the planet is too close to the Sun, and the Hubble doesnít want to risk an observation. Hubble can capture any changes on our planets and moons the same day they occur. This is because light takes only 5 hours to travel from the furthest planet, Pluto, back to the Hubble. It takes just a few minutes for light to travel from the Hubble to Mars because Mars is much closer than Pluto.
From July 16-22, 1994, 21 pieces of Comet Shoemaker 9 crashed into Jupiter with the force of millions of nuclear bombs. Hubble was able to take pictures of Jupiter during and after the collision. It was also able to detect that some of the black debris from Jupiter contained large amounts of sulfur and ammonia.
The Hubble also found that Jupiterís winds blow in the opposite direction compared to how the winds blow on Earth. The winds on Jupiter blow from its poles to the equator.
In December 1994, awesome pictures of Saturn were sent back to Earth from Hubble. Hubble picked up evidence of a rare storm occurring on Saturnís surface.
Astronomers discovered that Saturnís rings are only 300 feet thick, but are 171,000 miles across.
Hubble also discovered that astronomers were wrong when they thought Saturn had 18 moons. Now most astronomers think the moon count on Saturn should be raised up from 18 to 22. That would raise the moon count of our solar system from 60 to 64.
The Hubble Space Telescope has shown astronomers that the volcanic activity on Venus seems to be slowing down, so the planetís atmosphere is getting cleaner as less sulfur dioxide is produced. Since Venus has a surface temperature of 870 degrees Fahrenheit, which is hot enough to melt some metals, Venus would not be a very friendly place to visit.
The Hubble Space Telescope took pictures of the dust storms on Mars and found out that they were seasonal. They are partly caused by the planetís elliptical orbit, which causes Mars to be closer to the Sun than at other times of the year. The dust storms on Mars get worse when Mars is closest to the Sun, and the atmosphere gets colder as Mars moves farther away from the Sunís warming rays. As the temperature on Mars drops, the dust freezes and settles on the ground. Since the dust settles, Mars becomes even colder. The Hubble also shows that the water on Mars has frozen into ice-crystal clouds, allowing the planet to become drier, too.
The Hubble Space Telescope is gathering weather information on Mars. Astronomers have discovered a decrease in the planetís temperature. The planet is cooler than ever seen before. The Hubble provides important information for planning future space travel to Mars.
Vesta is the brightest asteroid in the night sky, and it is the only asteroid visible to the naked eye. The Hubble Space Telescope has taken pictures of Vesta as it goes around the Sun. Some astronomers think Vesta should be promoted to a higher level of importance, becoming the sixth earth-like planet.
Stars and Galaxies
Stars live and die over billions of years. The Hubble Telescope has taught us a lot about stars by taking snapshots of them at different stages from their birth to their death. Hubble has captured excellent views of newly forming stars in a galaxy called the Orion Nebula. Hubble has also captured the final days of stars giving us new information into how complex stars are.
Most galaxies have huge black holes at their center. A black hole is an object so massive and dense that nothing, not even light, can escape from its powerful gravitational force. Instruments like the spectrograph on Hubble can determine the presence of black holes.
The Hubble Space Telescopeís mission will come to an end in 2010. The telescope has provided us with great information on our universe and amazing images from space. It has also left a lot of unanswered questions. The Next Generation Space Telescope (NGST) is being designed right now and may be launched in 2009. It will be 10 times more powerful than Hubble, and it will look deeper into the universe than ever before, back to when galaxies were first formed. Scientists using NGST hope to discover and understand even more about our fascinating universe!
Unless otherwise noted, all images courtesy of NASA. Permission for use at http://www.nasa.gov/gallery/photo/guideline.html.
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