Download Tools of Astronomy

Tools of Astronomy
1. The Universe is so vast that it is hard to comprehend ________. A light year is a unit of
________ and is the distance light travels in one year. Light travels at a rate of 3 x 106 m/sec.
Light can wrap around the Earth almost __ times in one second! 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
__ hours to reach Pluto. How long does it take light to reach the nearest ______?
3. Proxima Centauri is our nearest star. It is ___ light years away! In other words…. It would
take light, traveling at a rate that takes it all the way across the United States and halfway back in
one second, almost four and a half ________ to get just to the nearest star!
4. Let’s fly out across the Milky Way which is ___________ light years across! This journey
would take over 100 thousand years even if we could travel at the speed of light which we can’t!
It would take ________ years moving at the world record space craft speed of 157,100 mph to
reach Proxima Centauri ! We’re just not going to visit any _______ anytime soon….. if ever!
5. And that’s just what’s in or local neighborhood! Our Galaxy is a collection of about ___ billion
stars, and there are at least 300 billion other ________! Our nearest neighboring galaxy is the
Andromeda galaxy. It is an incredible ________ light years away! Here is a view looking back
with Earth at the center from _____ million light years. How can we ever know anything about
our Universe?
6. All the information we receive beyond the Earth comes through the ______________ spectrum
(light) radiating from other stars and galaxies. Recall that light travels as a ________. The
electromagnetic spectrum is full of waves, long and________. Most of it we cannot see with our
eyes, but we can build receivers to “see” it. Waves carry _____________ that we can interpret to
understand what produced the light. E-M Waves ____________ through empty space!
7. Light takes _______ to travel the vast distances in the Universe so….(this is really an
important point)... When we look at objects in the Universe we are seeing them in the _______!
If a star is _____ 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 _______ years ago!
8. Telescopes are like _______ machines because they look at objects as they were in the past!
There are telescopes that “see” all the different wave ______________ of the E-M spectrum!
9. There are 2 types of telescopes: ____________ & reflecting. Refracting telescopes focus light
through a objective ___________ lens onto an eyepiece. Galileo made his first historical
observations with a reflecting telescope. Reflecting telescopes focus light onto a ___________
onto an eyepiece. Modern light telescopes are reflecting telescopes. Isaac _____________ built
the first reflecting telescope.
10. The Earth’s Atmosphere ____________ EM radiation. The best telescopes are housed in
observatories at _________ altitudes. UV, x-ray, & gamma ray telescopes are put in __________
because the atmosphere ________ those light waves. Fortunately! The ___________ is the best
visible light telescope because it is above the atmosphere for the absolute clearest __________.
11. Astronomers use _________________ to determine the temperature and chemical
compositions of stars! A spectrograph breaks the E-M spectrum coming from stars into all its
individual _______________, long and short. When starlight radiates from the _______ of a star
the gasses in the outer layer of the star _____________ some of the wavelengths and astronomers
observes a spectrum with missing lines that look _________. They call this an adsorption
spectrum. This tells them what ______________ are in the star!
12. Most stars are ___% H, ____%He & other elements. Spectral absorption lines in an
absorption spectrum vary with _____________. Astronomers can tell the temperature of a star
based on the shifting of these ____________. The fact that stars are made from the same elements
found on Earth means we can ___________ so much more about stars! Over ________________
spectral lines appear in absorption spectra from the ________!
13. Name the galaxy that you live within! _____________________________________