| Page |
Location |
Original |
Revision |
Date Posted |
| 72 |
par. 2 |
"Neither brightness nor...are from Earth." |
"Another technique is often used to find the distances to galaxies. To determine the distance to a galaxy, astronomers once again use the spectroscope. As you have read, light from a star moving away from Earth has a red shift in its spectrum. Astronomers measure the amount of red shift in a galaxy's spectrum and use a mathematical formula to calculate approximately how far away from Earth the galaxy is." |
07-Mar-2000 |
| 73 |
par. 2, lines 9–10 |
"Of course, not all the light from nuclear fusion is visible light." |
"Of course, not all the energy a star produces is heat and light." |
07-Mar-2000 |
| 74 |
par. 2, line 3 |
"It measures 1.35 million..." |
"It measures 1.39 million..." |
07-Mar-2000 |
| 79 |
par. 4, lines 4–11 |
"...born from gases...to heat up." |
"...born from dust and gases in a nebula. Over time, some of the dust and gases in a nebula are pulled together by gravity. The dust and gases form a cloud within the nebula. Over millions of years, more and more dust and gases are pulled into the cloud. Compression of the gases cause the cloud to heat up. The hot contracting cloud of dust and gases is known as a protostar." |
07-Mar-2000 |
| 80 |
par. 1, lines 1–6 |
"When the temperature...heat and light." |
"When the temperature within the protostar reaches about 10,000,000°C, nuclear fusion begins. The protostar is now a star. As a result of nuclear fusion, the star soon begins to shine and give off even more heat and light." |
07-Mar-2000 |
| 81 |
Fig. 2-36, caption |
"This ring nebula, or planetary nebula,..." |
"The Ring Nebula, a planetary nebula,..." |
07-Mar-2000 |
| 81 |
par. 1, lines 7–9 |
"This drifting gas forms a ring around the central core of the star. This ring is called a planetary nebula--..." |
"This drifting gas forms a shell around the central core of the star. This shell is called a planetary nebula--..." |
07-Mar-2000 |
| 82 |
Fig. 2-39, caption |
"Notice the ring of gas..." |
"Notice the shell of gas..." |
07-Mar-2000 |
| 83 |
par. 5, lines 3–7 |
"Usually the radio...are called pulsars." |
"The energy is given off in narrow beams. As the neutron star rotates, the beams sweep through space like the beams of light from a lighthouse. From the Earth, the passing beam looks like a regular pulse of energy. Neutron stars that appear to give off pulses of energy are known as pulsars." |
07-Mar-2000 |
| 84 |
par. 1, line 1 |
"The neutron star in the Crab Nebula pulses at a rate..." |
"The neutron star in the Crab Nebula appears to pulse at a rate..." |
07-Mar-2000 |
| 88 |
True or False #6 |
"6. In an open universe, all the galaxies will eventually move back to the center of the universe." |
"6. In an open universe, all the galaxies will eventually move back together." |
07-Mar-2000 |
| 97 |
Fig. 3-4 caption, lines 5–7 |
"In fact, from 1979 to the year 2000 Neptune will be farther from the sun than Pluto." |
"In fact, from the years 1979 to 1999 Neptune was farther from the sun than Pluto." |
07-Mar-2000 |
| 102 |
par. 4, line 6 |
"... for only a few hours." |
"...for only an hour each." |
07-Mar-2000 |
| 104 |
Fig. 3-11, Diameter column |
|
Diameter
(km) |
| Jupiter |
142,700 |
|
|
Diameter
(km) |
| Jupiter |
142,800 |
|
07-Mar-2000 |
| 104 |
par. 1, lines 8–10 |
"In fact, the...be detected today." |
Delete sentence. |
07-Mar-2000 |
| 105 |
Fig. 3-11, Temperature column |
|
Temperature
Extremes (°C) |
|
High |
Low |
| Venus |
480 |
-33 |
| Jupiter |
29,700 |
-95 |
|
|
Temperature
Extremes (°C) |
|
High |
Low |
| Venus |
460 |
450 |
| Jupiter |
? |
-170 |
|
07-Mar-2000 |
| 109 |
par. 1, lines 7–10 |
"So even during the summer, temperatures on Mars are well below 0°C. That, of course, is why water on Mars stays frozen all year round." |
"So even during the summer, it is still very cold on Mars. Water on Mars stays frozen all year round." |
07-Mar-2000 |
| 111 |
par. 1, line 4 |
"A hundred..." |
"About 40..." |
07-Mar-2000 |
| 112 |
par. 4, lines 1–2 |
"Because of the thick cloud cover, the atmospheric..." |
"Because Jupiter is so massive, the atmospheric..." |
07-Mar-2000 |
| 112 |
par. 4, line 9 |
"The magnetic field, called the magnetosphere,..." |
"Jupiter's magnetosphere..." |
07-Mar-2000 |
| 113 |
Fig. 3-21, caption, lines 3–4 |
"What are the four large inner moons called?" |
"What are the four largest moons called?" |
07-Mar-2000 |
| 113 |
par. 3, lines 3–4 |
"And although at least sixteen moons have now been found orbiting Jupiter,..." |
"And although at least seventeen moons have now been found orbiting Jupiter,..." |
27-Apr-2000 |
| 116 |
par. 4, lines 3–5 |
"So far, twenty-one--and possibly two more--moons have been found orbiting Saturn." |
"So far, nineteen moons have been found orbiting Saturn." |
27-Apr-2000 |
| 118 |
par. 4, lines 1–3 |
"The Voyager 2 flyby confirmed the fact that Uranus has fifteen moons, ranging in diameter from 32 to 1625 kilometers." |
"The Voyager 2 flyby confirmed that Uranus has fifteen moons, and two more have recently been discovered." |
27-Apr-2000 |
| 119 |
par. 4, line 5 |
"Neptune also glows with a blue-green color." |
"Neptune also has a blue-green color." |
07-Mar-2000 |
| 123 |
par. 1, line 9 |
"Astronomers have been looking for such..." |
"Astronomers once looked for such..." |
07-Mar-2000 |
| 123 |
par. 2, lines 1–3 |
"What if no...Uranus and Neptune? Other possibilities exist." |
"Other possibilities existed." |
07-Mar-2000 |
| 123 |
par. 3, lines 1–2 |
"Some astronomers have...They suggest that a black hole..." |
"Some astronomers...They suggested that a black hole..." |
07-Mar-2000 |
| 123 |
|
|
add 4th paragraph:
"It turned out that Lowell's calculations contained an error. There were no unexplained variations in the orbits of Uranus and Neptune. Astronomers have concluded that there is no Planet X." |
07-Mar-2000 |
| 123 |
Fig. 3-35. caption, line 1 |
"Astronomers wonder..." |
"Astronomers once wondered..." |
07-Mar-2000 |
| 123 |
Fig. 3-35. caption, line 4 |
"There are three..." |
"There were three..." |
07-Mar-2000 |
| 125 |
par. 3, lines 1–3 |
"Most meteors burn up in the atmosphere....A meteor that strikes Earth's surface is called a meteorite." |
"Most meteoroids burn up in the atmosphere....A meteoroid that strikes Earth's surface is called a meteorite." |
07-Mar-2000 |
| 129 |
par. 5, lines 5–6 |
"...powered by gunpowder or some other solid fuel would not be..." |
"...powered by gunpowder would not be..." |
07-Mar-2000 |
| 129 |
par. 6, line 1 |
"Solid fuels burn rapidly and explosively." |
"Gunpowder burns rapidly and explosively." |
07-Mar-2000 |
