Download Tools of Modern Astronomy Slide Show

Tools of Modern Astronomy Slide Show
1. A light year is a unit of ______ and is the distance light travels in one year. Light
travels at a rate of _________ and travels 1.5 x 1015 m/year. At that speed light travels
almost 6 trillion miles in one _____!
2. It takes light from the Sun about ___ minutes to reach the Earth. It takes light from
the Sun 6 hours to reach Pluto.
3. Proxima Centauri is our nearest star. It is ____________ away!
4. Let’s fly out to beyond our galaxy, the Milky Way, a distance of over _________ light
years!
5. Our Galaxy is a collection of about ___________ stars, and there are about
_____________ other galaxies!
6. All the information we receive beyond the Earth comes through the
______________________(light) radiating from other stars and galaxies (huge
collections of stars). When we look at objects in the Universe we are seeing them in the
________! If a star is 100 light years from Earth then the light from that star took 100
years to get here and we are seeing the star as it was ________ ago!
7. There are telescopes that exploit all the different ________________ of the E-M
spectrum!
8. There are 2 types of visible light telescopes: __________ & _____________.
Refracting telescopes focus light through a objective _____________ lens onto an
eyepiece. Reflecting telescopes focus light onto a __________ onto an eyepiece.
9. The Earth’s _______________ distorts EM radiation. UV, x-ray, & gamma ray
telescopes are placed on _____________ for best “seeing”. The _____________ is the
best visible light telescope because it is above the atmosphere.
10. Astronomers use _______________ to collect chemical composition and temperature
data about stars. The light shining from the interior of a star is a _______________
spectrum. Elements in the outer atmosphere of a star absorb certain wavelengths (colors)
and emit a _____________ spectrum in all directions. The resulting radiation of the star
is called an ______________ spectrum. Astronomers can identify _____________ in a
stars atmosphere by the dark absorption lines in the absorption spectrum that reaches
Earth.
11. Most stars are ___% H, ____%He, & other elements. Spectral absorption lines in an
absorption spectrum vary with _______________. Astronomers can tell the temperature
of a ________ based on the appearance of these lines. They compare them to a database
of known spectrum lines for each element at ____________ temperatures.