Astronomy 10 Flashcards
What is “The (Whole) Universe”
Everything.
Past, Future, Up, Down, Known, Unknown
When was the beginning of the universe
13.8 billion years old
How do scientists measure distances in space?
- Astronomical units
- Light Years
What are Astronomical Units? How to represent them?
Represented by the distance between earth and the sun
150 000 000 km = 1 AU
2 Important parts of a wave
Wavelength:
Distance from the same place on a way at two points in time.
Ex. Top and top or bottom and bottom
Frequency:
The number of times a wave passes the same point in a specific timeline
High frequency will have many oscillations
What is a Lightyear(s)? How sit it measured?
Measured by the distance light travels in one year, approximately 10 trillion kms.
We have 2 ways to measure because the closest star (besides the sun) is more than 268 000 AU away.
Different in long and short wavelength
Long wavelength:
Low frequency
Low energy
Short wavelength:
High frequency
High energy
What is a Electromagnetic Spectrum?
It shows certain waves have certain properties. Such as wavelength, frequency and energy.
What is Electromagnetic Radiation?
Celestial objects give off electromagnetic radiation
The specific wavelengths emitted by an object can tell scientists about its size, composition, distance, motion, etc.
The appearance of an object depends on the wavelengths being measured.
Things are not expanding at the same ___: objects that are ___ away are moving away from us more ___ than objects that are ___ to us.
rate
further
quickly
closer
What is The Doppler Effect
The Doppler Effect is the change in wavelength of a wave as an object is moving towards or further away from an observer.
If an object is moving towards you, the wavelength shortens (gets squished) and the sound goes up in pitch. (NOT volume)
If an object is moving away from you, the wavelength lengthens (gets stretched) and the sound goes down in pitch.
The Doppler Effect refers to ___ as well as ___.
sound and light
Using a spectroscope, astronomers can look at the light wavelengths coming from a star.
Every star has a different light spectrum, depending on the concentration of different elements in that star. Here is what our sun’s light spectrum looks like.
Red Shifted =
Moving away
Blue Shifted =
Moving towards
What is the Cosmic Microwave Background Radiation
For the first 300 000 years of the Universe, it was too hot for light to escape the plasma that existed everywhere.
When the temperature cooled enough, a massive “blast” of light from everywhere, all at once, started travelling through space.
