The Solar System Exam #2

What is emmiting light?

Light emission occurs when atoms transition from a higher energy to a lower energy state

How do light and matter interact?

By emission, Absorption, transition, reflection and refraction

What does an Emission Spectrum look like?

What does an Absorption Spectrum look like?

What is light?

A particle and wave. They bounce around and carry momentum and energy

What is a blue shift?

Shorter wavelength, moving towards us, carries more energy (Negative)

What is a red shift?

Longer wavelength, moving away from us, carries less energy (Positive)

Why do sources of light get dimmer when they are far away?

It has to do with the energy spreading on a surface; the bigger the surface, the less surface energy per unit of area

What is the color white?

Its all the color wavelengths blending together

What is the color black?

It is the absence of light

What is Blackbody Radiation?

Light-matter interaction; direct result of microscopic motions of particles

How can an atom store energy?

Atoms can emit/absorb photons; it is how astronomers study physics properties of planets and stars

what does it mean when wavelength and energy are not the same?

Wavelength and energy are inversely proportional rather than the same thing. A longer wavelength means shorter energy and shorter wavelength means higher energy

What is the emission line spectrum?

Lacks blackbody radiation, light is seen only at certain specific wavelengths, hot gas cools down

A hot object, dense and gas produces what kind of spectrum?

Continuous Spectrum

A cool gas in front of a continuous source of light produces what kind of spectrum?

Absorption Spectrum

A hot, low-density gas produces what kind of spectrum?

Emission line spectrum

What is the doppler effect?

The change in the frequency or wavelength of a wave (such as sound or light) as measured by an observer moving relative to the wave source

What is the purpose of telescopes?

For gathering protons to see dim objects

The larger the mirror or lens (aperture)

The more brigther the image will be

Larger telescopes have…

Smaller field of view

Smaller telescopes have…

Larger field of view

How do you get good resolution on telescopes?

Larger telescopes and detectors with smaller-size pixels

What are refractor telescopes?

Telescopes that have glass lens that can bend light

What are reflector telescopes?

Telescopes that have mirrors that can bend light

What’s a main problems with refraction telescopes?

Chromatic aberration, image distortion, air bubbles, flexion

What is chromatic aberration?

An optical defect where a lens fails to bring all colors of light to the exact same focal point

What are some problems with reflector telescopes?

Rays focus at various locations (Spherical aberration), Light goes back towards sky

Why is it difficult to build large mirrors for telescopes?

Heavy, glass expands with heat, takes a long time to build

What are some ways that photons were recorded?

Charged-coupled devices (CCDs), Eyes with pen and paper, photographic plates, Other detectors (Infrared, UV, Gamma rays, Xray’s)

What makes a detector better than another?

• Eyes don’t add up protons

• Photographic plates makes it difficult to quantify light

• CCDs are more efficient (Hook it up to a computer)

What can ground-based telescopes do?

Can travel through various medias more easily than visible and UV light

What are radio telescopes?

They collect photons with much long wavelengths (radio range); also look like satellite TV dishes

Why do we put telescopes at the highest point?

Less atmosphere, less twinkling, less absorption

What is twinkling and can we get rid of it?

An optical effect caused by Earth's turbulent atmosphere bending and refracting starlight before it reaches the lens or mirror. We can’t get rid of it but we can work around it

How can we work around the problem of twinkling?

• Put telescopes at highest points

• Use Adaptive Optics

• Send telescopes in Space

What does the atmosphere affect telescopes/twinkling?

Because Earth’s atmosphere is full of moving turbulent layers of air with different temperatures and densities

What are adaptive optics?

Measures and correction light distortions in real time to produce crystal-clear images

What is light pollution?

Prevents us from seeing the night sky due to man made lighting; can be a porblem for ground based telescopes

How can we get around the problem of light pollution?

• Put telescopes in dark skies and away from radio sources and cites

• Send telescopes in space

What are the pros of getting rid of atmosphere for telescopes

• Observe 24/7

• No twinkling

• No weather Issues

• No light pollution

What are the cons of getting rid of atmosphere for telescopes

• Cost of operation

• Failures are impossible to repair

What are the properties that considers an object a planet?

• Must orbit the sun

• Be massive enough to sustain gravity

• Be large enough to clear away objects and debris in its path

What are the properties that considers an object a dwarf planet?

• Most orbit the sun

• Have nearly round shape

What is the solar system made up of?

Gas and dust that formed as a large cloud

The sun is made up of how much percentage of H and He?

74% H and 24% He

The rocky planets are made up of what elements?

C, N, O, Si, Fe, Ni

Planets must have formed from matter that was…

Enriched with heavy elements or depleted of light elements

At what time did the Solar System formed?

After the big bang where the solar nebula is filled with heavy elements

What elements occur during the Big Bang?

H, He, Li

What process helps create heavy elements?

Nuclear fusion

How do we know the age of the solar system?

Radiometric dating (Half-Life)

How can we tell if a planet and moon is younger from one another?

If an object has a lot of craters, than its old

What is the Nebular hypothesis?

Explains the arrangement of planets and why planets orbit in the same direction

What is the protoplanetary disk?

Models that predict that a disk-bulge take shape in the earliest stage

What are planetesimal debris?

Pieces of clumps that attract small pieces with gravity; seeds to grow planets

What is the frost line?

The boundary at 3 AU (between Mars and Jupiter) where gas giants live

How did the solar system form?

from the gravitational collapse of a giant, rotating cloud of gas and dust known as a solar nebula, likely triggered by a nearby supernova shock wave