11) Exploring The Solar System ✅ Flashcards
What are the planets in our Solar System?
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
What are the four terrestrial planets?
Mercury
Venus
Earth
Mars
What are the similarities between the terrestrial planets?
They are all relatively small rocks surrounding iron cores
What are the four gaseous giant planets?
Jupiter
Saturn
Uranus
Neptune
What are the similarities between the gaseous planets?
The gaseous planets have liquid interiors and substantial atmospheres of hydrogen and Helium with traces of methane and ammonia. They also have complex ring systems and large amounts of Moons
What are the planets that have rings?
Jupiter
Saturn
Uranus
Neptune
Why aren’t dwarf planets considered planets?
They lack the gravitational force needed to sweep debris out of their orbit.
They also don’t consistently stay in the zodiacal band
Where are the dwarf planets found?
All the dwarf planets (except Ceres) are found in the Kuiper belt
Where is Ceres found?
Ceres is found in the Asteroid belt
What are the 4 notable dwarf planets?
Ceres, Pluto, Eris and Makemake
What are SSSO’s?
Small Solar System Objects which include asteroids, meteoroids and comets
How large are the diameters of SSSOs?
<1000km
Where are most asteroids found?
Most Asteroids are found in the Asteroid Main Belt between the orbits of Mars and Jupiter
How big are asteroids?
Asteroids range from ~10 m to ~1000 km; most have irregular shapes
What is the structure of comets?
Where do Short-term comets originate from?
Kuiper Belt
What is the life period of a short-term comet?
< 200 years
Why do some short-term comets go into elliptical solar orbits?
The gravitational influence of Neptune nudge the comets into solar orbits; these have a subset period of < 20 years
Where do Long-period comets originate from?
Oort Cloud, a spherical distribution of icy bodies about halfway to the nearest star
Where is the Oort cloud?
A spherical region which is around 5000 to 100,000 AU away from the Sun
Where is the Kuiper belt?
The Kuiper Belt is a region of the Solar System outside the orbit of Neptune.
Its inner edge begins at the orbit of Neptune, at about 30 AU from the Sun and ends at approx 1,000 AU from the Sun.
What is the life period of a long-term comet?
> 200 years
How do long-period comets differ from short-period ones?
- They have unpredictable orbits
- Highly-inclined to the plane of the Solar System
- Some orbiting in the opposite sense to that of the planets
What happens as the comet approaches the Sun?
Rarefied gasses and dust envelop the nucleus of dust and ice; eventually, one or more tails develop that can be several million kilometres long
What happens as the comet moves away from the Sun?
The tail and the comet become less visible. The comet ceases to be influenced by solar radiation, fades from view and returns to the outer Solar System.
In what direction does a comet ion tail face?
In the opposite direction to the sun
What does the orbit of a long period & short period comet look like?
Describe a comet’s ion tail.
A comet’s ion tail is long, straight and predominantly blue in colour
Why does a dust tail form?
Due to radiation pressure from the sun
What is the shape of a dust tail from a comet?
Curved
How long is a dust tail from a comet?
Several millions of kilometres long
Why can an observer easily see a comet’s dust tail?
It’s very bright to an observer due to the reflection of the ice particles from the sun
Where is the heliosphere?
It is thought to be between 80 and 100 AU distance to the Sun.
Explain what the heliosphere is?
It is a ‘bubble’ surrounding the solar system, created by the solar wind
What is the shape of the heliosphere?
And what causes this shape?
‘cigar-shaped’
It is shaped by the Sun’s movement
Whats the difference between meteors, meteoroids and meteorites?
What are Meteoroids?
Meteoroids are particles of dust, rock and mixtures of stone, ice and metal that are in orbit around the Sun
What happens when a meteoroid enters the Earth’s atmosphere?
When a particle enters the Earth’s atmosphere, air resistance converts kinetic energy into thermal energy, heating the particles. This results in a streak of light visible in the night sky that is called a shooting star or meteor
What is a meteor shower?
A Meteor Shower is when the Earth passes through a meteoroid stream in the wake of a comet, many more meteors are visible
What is the radiant?
The radiant is the point where the individual meteors appear to diverge from a vanishing point. This is simply due to perspective. The shower is named after the nearest constellation
What is the speed of a particle once it has entered the Earth’s atmosphere?
20-70 km/s
What is a meteor shower named after?
The shower is named after the nearest constellation
What is a telescope’s aperture?
The telescope’s aperture is the size of the hole that light goes through
What is chromatic aberration?
Chromatic Aberration is when lenses tend to focus different wavelengths of light to slightly different points. This causes images to be blurred and unclear
What is the basic design of a Galilean telescope?
A Galilean refracting telescope uses:
- a concave lens as the eyepiece
- Is typically fixed focus
- limited field of view
What is the basic design of a Keplerian telescope?
A Keplerian refracting telescope uses:
- a convex lens
- Is larger or heavier as they are focusable but images are inverted.
What is the basic design of a Newtonian telescope?
- A reflector collects light at one end of a tube and reflects it off a concave mirror.
- It is brought to a focus by a secondary mirror further up the tube at a 45 degree angle which is then magnified using an eyepiece.
What is the basic design of a Cassegrain telescope?
- This reflects light from its concave lens to a secondary mirror.
- This mirror is facing the primary mirror and reflects the light back down towards the primary but focuses through a small hole behind the primary.
