Saving Hubble: a famous space telescope gets an out-of-this-world tune-up

Science World, Feb 18, 2008 by Jennifer Moser

Before you can be wowed by images captured by the Hubble Space Telescope, a lot happens behind the scenes. First, the telescope receives electromagnetic waves from an astronomical object. These waves range from near-infrared (the type of energy that heats your morning toast) to visible light to ultraviolet (the type of energy that causes sunburn).

Hubble converts that information into digital data that get transmitted multiple times until they reach the Space Telescope Science Institute in Baltimore, where scientists analyze the data and turn them into an image you can see.

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SUPERNOVA

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A supernova is the explosion of a dying star. This supernova, SN 1987A, was first observed 21 years ago. It actually blew up about 163,000 years ago, but the light took many thousands of years to travel here. Scientists think that the exploding star may have become a neutron star (a very dense collapsed star) or a black hole (a collapsed star with so much gravity that light cannot leave it) by now. SN 1987A showed scientists that star explosions are more complex than first thought. The star released gases for thousands of years before it actually exploded, which changed the shape of the remnant of the explosion.

NEBULA

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This is the Carina Nebula, one of Levay's favorite images. A nebula is a vast outer-space cloud of gases and dust. Some of the gases and dust come from dying stars, but nebulas also give birth to new stars. Gravity can pull some nebula gas and dust closer together--close enough to heat up. With this extra heat, nuclear reactions start to fuse hydrogen into helium, producing a star. In this photo, red shows sulfur, green shows hydrogen, and blue shows oxygen gas.

SPIRAL GALAXY

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Galaxies are vast bodies of gas, dust, stars, and planets. Galaxies may be elliptical (oval-shaped), irregular (a shape we do not have a name for), or spiral (like two curves curling around each other). This picture shows NGC 1300, a spiral galaxy. Our own solar system is in the Milky Way, which also is a spiral galaxy.

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To see more images Hubble has taken, visit: www.scholastic.com/scienceworld and click on "In this Issue."

PRE-READING PROMPTS:

* What is the Hubble Space Telescope and when was it launched?

* Why are the images captured by Hubble much clearer than those taken by ground-based telescopes?

* How does a space telescope transmit information to scientists on Earth?

DID YOU KNOW?

* Hubble moves around Earth at a speed of 8 kilometers (5 miles) per second. It takes the telescope approximately 97 minutes to complete one orbit.

* When completed in 2016, the Giant Magellan Telescope--a ground-based telescope located in Chile--will produce images 10 times sharper than the ones captured by Hubble.

CRITICAL THINKING:

* Hubble is at work 24 hours a clay, 365 days a year. It requires a team consisting of many different types of workers to keep the mission running smoothly. Can you think of the different types of careers involved in "Team Hubble"? For information, visit: http://hubblesite.org/the_telescope/team_hubble/