Ay [T4] - The Solar System Flashcards
What are comets made of and what size are they typically in diameter?
Comets are made mainly of ice and dust - they’re remains of the formation of the solar system, typically 10km in diameter
What is the tail of a comet?
Most visually impressive part.
Steam of dust and gas left behind the comet as it travels and reacts to the Sun’s radiation
What are the names of the two tails that comets have?
Ion tail and Dust tail
What is the ion tail caused by?
Solar wind excites elements in the tail
What direction does the ion tail face?
Same direction as sun
What is the Dust tail?
Bits of comet breaking off because it heats up as it passes close to the sun
What is the coma?
The thin atmosphere formed around the nucleus, created by gases expelled from the core
What is the nucleus?
Solid core of comet (rocky, icy part)
What is the difference between a dwarf planet and a planet?
Dwarf planets don’t have a clear path, or “cleared its neighborhood” of objects, because there are lots of similar sized objects nearby
What is the difference between a meteor, meteoroid and meteorite?
A meteoroid is before it comes into the Earth’s atmosphere and burns up
A meteor is when it’s in the Earth’s atmosphere and is burning up
A meteorite is when it’s hit the ground on earth and is just pieces of rock on the ground
What happens to a meteor while in the Earth’s atmosphere?
The temperature of it increases enough to give off light
What 4 areas can our solar system be roughly split up into?
The terrestrial planets, the asteroid belt, the gas giants and the kuiper belt.
What are the terrestrial planets?
Mercury, Venus, Earth, Mars
4 relatively small planets made of rock surrounding iron cores
What is the asteroid belt?
A large ring of asteroids separating the terrestrial planets from the gas giants
What are the gas giants?
Jupiter, Saturn, Uranus and Neptune
4 larger planets orbiting the sun
What is the kuiper belt?
A large collection of small solar system objects (asteroids, meteorites and comets)
What is the Oort Cloud?
The edge of the Sun’s gravitational field
What is the heliosphere?
The edge of the Sun’s magnetic field
1 AU = ? m
1 AU = 1.5 × 10¹¹m
What are short and long period comets?
Short period comets: take less than 200 years to orbit around the sun once
Long period comets: take more than 200 years to orbit around the sun once
Where do short period comets with a period less than 20 years originate?
The Kuiper Belt
Where do long period comets originate?
The Oort Cloud
1 ly = ? m
1 ly = 9.5 × 10¹⁵m
Would there be meteor showers on the moon?
No, because a meteor is only a meteor if it’s in an atmosphere, and the moon does not have an atmosphere
What type of orbit do comets have, and where do they move fastest?
Elliptical orbit
Move fastest closest to the sun
What is the ecliptic plane?
The plane that the sun and planets approximately lie on
What does planets being on the same plane tell us?
They formed roughly at the same time, from the same disc of material
What does aperture mean?
Opening
What are the 3 types of telescopic power?
Collecting power/light grasp, magnifying power and resolving power
What does light grasp mean?
A measure of how much light the telescope can capture
The larger the telescope…
…the more light collected
What is light grasp proportional to?
Light grasp ∝ area ∝ (diameter of objective element)²
What is magnification dependant on?
The focal lengths of the eye piece and the objective
What is the resolving power?
A measure of how sharp the image produced is - how much detail the image is in
What is the resolving power dependent on?
The wavelength of light
The smaller the wavelengths…
…the higher the resolution images
What does FOV stand for, what is it a measurement of, and what is it measured in?
Field of view, a measurement between 2 extremes of your vision, measured in degrees
What is an advantage of a Galilean Refracting telescope?
Provides an upright image without requiring an erector-lens system
What is a disadvantage of a Galilean Refracting telescope?
Small FOV - can only reveal approximately ¼ of the moon’s surface at a time
Draw a Galilean Refracting telescope
What is an advantage of a Keplerian Refracting telescope?
Much wider FOV and greater eye relief - higher magnifications
What is a disadvantage of a Keplerian Refracting telescope?
Strong “chromatic aberration”
What is chromatic aberration?
Image distortion (dispersion of different wavelengths of light)
Draw a Keplerian Refracting telescope
What is an advantage of a Newtonian Reflecting telescope?
Long equivalent focal lengths - large magnification
What is disadvantage of a Newtonian Reflecting telescope?
Heavy, hard to store
Draw a Newtonian Reflecting telescope
What is an advantage of a Cassegrain Reflecting telescope?
Doesn’t have chromatic aberration
What is disadvantage of a Cassegrain Reflecting telescope?
Difficult to use
Draw a Cassegrain Reflecting telescope
What is a fly-by?
The probe literally flies past a target and in most cases allows studies of many targets to be made
What is an orbiter?
A probe that orbits it’s target
What is an impactor?
Involving a deliberate crash-landing into the target body
What is a soft lander?
The descent and impact are controlled and the probe lands on the surface of the target body in tact
What type of space probe is New Horizons?
Fly-by
What type of space probe is Juno?
Orbiter
What type of space probe is Dawn?
Orbiter
What type of space probe is Deep Impact?
Impactor
What type of space probe is Philae?
Soft Lander
What was the target of New Horizons?
Pluto and the Kuiper Belt
What was the target of Juno?
Jupiter
What was the target of Dawn?
Vesta and Ceres
What was the target of Deep Impact?
Comet 9P / Tempel 1
What was the target of Philae?
Comet 67P / Churyumov-Gerasimenko
What was the aim of the mission for New Horizons?
Pluto fly-by, Kuiper belt fly-by
What was the aim of the mission for Juno?
Explore the Jovian system
What was the aim of the mission for Dawn?
Visit Vesta and Ceres
What was the aim of the mission for Deep Impact?
Probe beneath the surface of a comet
What was the aim of the mission for Philae?
Comet orbit and landing
What major discoveries were made during New Horizons’ mission?
First spacecraft to explore Pluto up close.
Large, young, heart-shaped region of ice on Pluto
Many mountains made of water and ice on Pluto
Kuiper belt- most distant object ever explored up close
What major discoveries were made during Juno’s mission?
Been beneath the dense, forbidding clouds encircling Jupiter - first orbiter to peer so closely
Close up images of Jupiter’s “tortured moon” Io
What major discoveries were made during Dawn’s mission?
First spacecraft to orbit 2 extraterrestrial destinations - the giant asteroid Vesta and the dwarf planet Ceres, both in the asteroid belt
First spacecraft to orbit a dwarf planet
What major discoveries were made during Deep Impact’s mission?
Determined that a comet’s surface is very porous
Discovered that hyperactive comets are driven by carbon dioxide
What major discoveries were made during Philae’s mission?
Successfully landed on the surface of the comet and began sending back images and data
