Space Exploration part two Flashcards
What are the 2 types of optical telescopes?
1) Refracting telescope- use 2 lenses limited to 1m diameter
2) Reflecting telescope- use concave mirrors
What is Interferometry?
Using a combination of telescopes together to obtain mroe detailed images of distant objects.
What is wavelength?
Measurement from one point on a wave to the same point on the next wave. Usually crest to crest or trough to trough.
How do you measure wavelength?
In micrometers; one millionth of a meter.
What is frequency?
Number of waves per second (usually measured in Hz).
What is the inverse relationship between wavelength and frequency?
All electromagnetic energy travels at the same speed: so if wavelength increases, frequency decreases.
What are radio telescopes?
Gather radiowaves from distant stars, nebula, galaxies, planets. Radio waves not affected by weather, time of day, clouds, pollution, atmosphere. Radio telescopes have been used to map out neutral hydrogen and determine shapes of galaxies.
What are space probes?
Unmanned satellites or remote controlled landers (sent to all planets except Pluto).
What is radio interferometry?
Multiple radio telescopes combined for greater resolving power. The greater the distance between telescopes the greater the accuracy.
What is an array?
Group of telescopes used together.
What is triangulation?
By measuring the angles between a baseline and the target object you can determine the distannce to that object.
What is parallax?
The apparent shift in position of an object when the object is viewed from 2 different places.
What is whitelight?
Combination of all colours and can be seperated into its component colours (visible spectrum).
What is the Doppler affect?
Sound waves become compressed in front of a moving object stretched behind it. This makes the pitch higher as the object moves towards you and lowers as it moves away from you.
How many astronauts have been killed so far during space travel?
22
