Unit E Section 3.2

Question 1

Optical telescopes give us information based on

Answer 1

visible light

Question 2

What can also emit radio waves, infrared (heat) waves, and X-rays?

Answer 2

However, objects in space, such as stars and galaxies

Question 3

What are radio waves, infrared (heat) waves, and X-rays?

Answer 3

These are all forms of ELECTROMAGNETIC ENERGY.

Question 4

What is Wavelength?

Answer 4

is a measurement of the distance from one point on a wave (such as the crest) to the same point on the next wave.

Question 5

What is Frequency

Answer 5

is the number of waves that pass a single point

in one second.

Question 6

Energy with a high frequency has what amount of length?

Answer 6

has a short wavelength

Gamma rays, for instance, have a high frequency (1020 waves per second) and a very short wavelength (less than a millionth of a centimeter)

Question 7

how fast does Electromagnetic energy travel?

Answer 7

This energy travels at the speed of light, 300 000 km/s, but has different wavelengths and frequencies from those of light.

Question 8

How much frequency do radio waves have?

What about the wavelength

Answer 8

Radio waves have a low frequency,

but wavelengths that can be several kilometers long.

Question 9

electromagnetic spectrum?

Answer 9

the range of wavelengths or frequencies over which electromagnetic radiation extends.

-The visible light we see all around us occupies a small section of the entire electromagnetic spectrum, which covers the whole range of electromagnetic energy

Question 10

Visible light has a wavelength

measured in?

Answer 10

micrometers (written as µm)

One micrometer is 1 millionth of a meter

Question 11

Where are the Radio waves received from in the vast solar system?

Answer 11

from stars, galaxies, nebulae, the Sun, and even some planets—both in our own solar system and in others

signals are mapped through the use
of sophisticated electronics and computers.

Question 12

What are the advantages of RADIO TELESCOPES:

Answer 12

• Radio waves are not affected by weather and can be detected during the day and at night.
• They are also not distorted by clouds, pollution, or the atmosphere as are light waves.
• astronomers have discovered much about the composition and distribution of matter in space—information that cannot be detected by optical equipment.

Question 13

Because the wavelengths of radio waves are so large

What should happen to the antennae?

Answer 13

the antenna of a radio telescope

must be large.

Question 14

What are radio telescopes made of?

Answer 14

metal mesh

Question 15

Radio telescopes resemble:

Answer 15

Their shape resembles that of a satellite dish: they are curved inward, with a receiver at the middle.

Question 16

What is the curved position of a radio telescope is what?

Answer 16

-The curved portion of the dish is really a large antenna that intercepts and focuses radio waves before transmitting them to the receiver.

There, the waves are transformed into an electrical signal that is fed into a computer for interpretation.

Question 17

several small radio telescopes can be combined to

achieve?

Answer 17

to achieve greater resolving power than one large radio telescope can achieve

Question 18

interferometry?

Answer 18

combining several radio telescopes for better performance and accuracy of radio images.

Question 19

the bigger the separation between the telescopes (interferometry)…….

Answer 19

the more detail

astronomers can measure.

Question 20

arrays

Answer 20

more telescopes are arranged into groups called arrays

Question 21

The benefit of arrays?

Answer 21

The accuracy of measurement is increased

even further if more telescopes are arranged into groups called arrays.

Question 22

Example of arrays?

Answer 22

The accuracy of measurement is increased

even further if more telescopes are arranged into groups called arrays.

Question 23

Benefits of infrared spectrum through a radio telescope?

Answer 23

When observed through an optical telescope, a
planet orbiting a distant star is practically invisible because of the light given off by the star

when viewed in the infrared spectrum through a radio telescope, the brightness of the star is reduced and the planet’s brightness peaks.

Question 24

What are the various sources in space from which radiation comes from?

Answer 24

• infrared image of a young star cluster
• X-rays that are being emitted from objects such as black holes and pulsating stars;
• and huge bursts of gamma rays that appear without warning and then fade

Question 25

Are bursts of gamma rays predictable?

Answer 25

Bursts of gamma rays occur unpredictably in different parts of space.

Although they may last only a few seconds or minutes, they give off more energy than our Sun would produce in its entire 10-billion-year lifetime.

Question 26

What are space probes?

Answer 26

Space probes are unmanned satellites or remote-controlled “landers” that put equipment on or close to planets where it would be too difficult or dangerous to send humans to.

Question 27

What are the achievements of space probes?

Answer 27

Space probes have been used to carry out remote sensing on Mercury and Jupiter, sample soil on Mars, land on Venus, and study the nature of Saturn’s rings

Question 28

Besides Earth, the only other body in the solar system that has been physically explored by humans is……

Answer 28

the Moon

Question 29

When was the first trip to the moon by humans accomplished?

Answer 29

Apollo 11 mission in 1969