An introduction to color and to both line spectra and continuous spectra, with applications to sunlight. ... This lesson plan supplements: "The Many Colors of Sunlight," section #S-4: on disk Sun4spec.htm , on the web . ... That cold atoms in a gas absorb the same colors as the ones they emit when hot, and that such absorbtion causes dark lines in the Sun's spectrum. ... One way of introducing the subject of color is through the rainbow. ... However, different colors are bent by different amounts. ...

... The greater the distance, the smaller the parallax. ... That triangle has the same proportions as the much larger triangle ABC, and therefore, if the distance B'C to the thumb is 10 times the distance A'B' between the eyes, the distance AC to the far landmark is also 10 times the distance AB. ... The most distant objects our eyes can see are the stars, and they are very far indeed: light which moves at 300,000 kilometers (186,000 miles) per second, would take years, often many years, to reach them. ...

Phoebe . Saturn IX . Phoebe [FEE-bee] is the last of the known satellites of Saturn, at a distance of 12.952 million kilometers (8 million miles). Phoebe orbits Saturn in a retrograde direction (opposite to the direction of the other satellites' orbits) in a plane much closer to the ecliptic than to Saturn's equatorial plane. ... Scientists believe that Phoebe may be a captured asteroid with a composition unmodified since the time it was formed in the outer Solar System . ...