Test 1 Flashcards
What are the different colors stars can be?
blue, white, yellow, brown, red and orange
Can stars have different shapes?
Yes they can
What are “fixed stars” ?
stars that never shift position and rarely vary in brightness
What are “wondering stars” ?
stars that move throughout the fixed stars and disappear for weeks, months, or years and then reappear
Why could the ancients see the sky with more clarity?
Because there was no light pollution back then
Are fixed stars static forever?
No, they move so slow that they do not seem to move over ones lifetime, but they do move over extremely long periods of time.
Which type of stars are the constellations built from?
Fixed stars
What are referred to as fiery-tailed streaking objects?
Comets
What is the difference between Asteroids and Comets?
Asteroids are made of rock and metals, Comets are made of ice, gas and dust.
What are asteroids made out of?
Rock and metals
What are comets made out of?
gas, ice and dust
where are comets thought to originate from?
The Oort cloud
What is the Oort Cloud?
A group of icy bodies in the outer solar system
Do comets change often?
They have remained largely unchained since they formed
What did ancient cultures believe when they saw comets?
They believed they were bad omens such as death of nobility, famine or attacks from the heavenly realm
What other elements can be found in a comets ice besides water?
Methane, ammonia or carbon dioxide
What is the difference between a coma and the hydrogen cloud, and what are they?
They are the same thing: When a comet near the sun, the frozen parts turn to gas that form a cloud around the nucleus which is referred to as a coma, or since it is filled with hydrogen, it is also referred to as the hydrogen cloud.
What causes the comet to have a tail we can see?
Radiation from the sun charges the dust particles of the comet causing it to scatter over 10 million km, which is the tail that we can see with the naked eye.
What is the difference between a perihelion and aphelion comet?
When a comet is closest to the sun in it’s respected orbit it is called a perihelion, and when it is farthest it is called an aphelion.
Do we see comets when they are perihelion or aphelion?
Since we are close to the sun, we see comets when they are in their perihelion phase.
What depicts the direction a comets tail is pointing?
No matter what direction the comet is moving, the tail will always point away from the sun because the tail is caused by the suns expelled radiation.
What is a meteoroid, meteor, and meteorite and what are their differences?
Small chunks of comets or asteroids are called meteoroids, when one makes it into earths atmosphere and burns up, they are called meteors, and when they hit earth without burning up, they are called a meteorite
Roughly what size does an asteroid or comet become a meteoroid?
When it is less that 10 meters across.
What is a shooting star?
Streaks made by small grain-sized pieces of space rock that have entered out atmosphere, travelling at thousands of kilometres per hour. As a result, the immense friction burns up the rock fragments.
Which planet acts as a shield to the inner planets?
Jupiter and it’s moons act as a shield for the inner planets resulting in far less space rocks hitting earth due to Jupiter’s immense gravitational pull
How many times bigger is Jupiter than Earth?
1300
What planet was responsible for changing Halley’s comet’s orbit?
Jupiter
When did halley’s comet get it’s name?
Halley’s comet was named on Christmas day in 1758 after it’s late predictor
What did wondering stars end up being?
planets reflecting sunlight, wondering along fixed path the “ecliptic”
What was constructed by humans to act as astronomical observatories or guideposts?
Pyramids and monuments
What is our Solar System comprised of?
the Sun, planets, moons, asteroids, meteoroids, comets and various other materials
What does the earth and moon revolve around?
a central point located just beneath the Earth’s surface
What does Pluto share it’s orbit with?
trillions of other rocks known as the Kuiper Belt
What is at the edge of our Solar System?
The Oort Cloud
What is a light year?
A light year is the distance that light would take a year to travel. which is 9.5 trillion km
What is the closest Sun (star) to our Solar System, and how far away is it?
The closest Star (Sun) to our solar system is Alpha Centauri, which is 4.3 light years away (40 Trillion km)
How fast is the speed of light?
300 000 km/s or around 1.1 billion km/h (1.080)
What constellation is Alpha Centauri apart of?
Centaurus
Describe the constellation “Crux”
a constellation that is made of four stars taking on a diamond (cross) shape
How long would it take to get to the closest star if we had a spaceship that travelled 100,000 km/h?
it would take us 46,436 years to get to the nearest star
How far apart are Alpha and Beta Centauri?
Alpha and Beta Centauri are actually 350 lightyears away from each other, they just appear to be close from our prospective. They are almost 100 times farther apart then us and Alpha Centauri
Is Alpha Centauri a single star?
Alpha Centauri is actually a star system comprised of at least two stars. A and B are so close together that they appear as one.
What is technically the closest star to us that we can’t see?
Proxima Centauri, but we say Alpha is the closest because we cant see Proxima for how small and dim it is.
is Beta Centauri a single star?
Beta Centauri is actually a triple star system, all extremely close to each other, and are about 15 times more massive than the sun, and are soon about to rapidly expand into Red Supergiant’s and then into Supernovae.
What are the next two closest stars following the Centauri’s?
Barnard’s Star is the next closest at a distance of 6 light years, followed by Wolf, which is 8.
What is our Galaxy called?
The Milky Way
Roughly how many stars lives in the milky way?
about 200 billion
How big is the milky way galaxy?
roughly 110 000 ly by 15 000 ly
What is the thickest part of a galaxy called?
The nucleus
What is the closest “spiral” galaxy to us, and how far away is it?
Andromeda, 2.5 million light years away
Where is the Andromeda Galaxy located in the sky?
When looking at the Andromeda Constellation, the Andromeda Galaxy is positioned just above the middle part of the upper arm.
What is the most distant object visible to the naked eye?
The Andromeda Galaxy
What is the actual closest Galaxy to us?
The large magellanic cloud
What is the average number of stars in a galaxy?
250 billion
How many Galaxies are they that we know of?
About 250 billion
What is the total amount of stars in our seeable Universe?
6.25 x 10 to the power of 22
Are stars luminous?
Yes
Are Planets luminous?
No
Where is the balance point or “barry center” located?
just inside of the earth’s surface
What is the order of all things in our solar system starting with the Sun?
Sun, Mercury, Venus, Earth, Mars, Asteroid Belt, Jupiter, Saturn, Uranus, Neptune, Kuiper Belt, Oort Cloud.
in light measurements how far away is the moon from earth?
1.29 light seconds
in light measurements how far away is the sun from earth?
8 light minutes
in light measurements how far away is mars from the earth?
12.7 light minutes
What is a Lunar Eclipse?
A Lunar Eclipse is when the moon is eclipsed by earth (earth is in-between the sun and moon blocking the sun from shining on the moon)
What is a Solar Eclipse?
A Solar Eclipse is when the sun is eclipsed by the moon (moon in-between sun and earth, blocking the sun)
How was the Earth formed?
The Earth was formed by means of the collective accumulation of space rocks. (planetesimals)
When was the Earth formed?
around 4.2 billion years ago
What kept the early stages of Earth molten?
Every time one of these planetesimals smashed into the Earth’s surface, tremendous heat was generated ensuring that all of the Earth’s rocks were in the molten state.
How was the Earths Core created?
The molten state of the Earth allowed the denser minerals and metals to sink towards the centre of the planet, while the lighter materials floated towards the surface.
How big is the Earth today compared to 4.2 billion of years ago?
Earth today is about 12760 km in diameter, which is about 50% smaller than it was when it was 4.2 billion years ago
How was the moon formed?
4.2 billion years ago an asteroid about 3000km in diameter smashed into the earth at thousands of kilometers per hour. This collision blew out a massive chunk of the Earth which solidified in the cold of space, eventually fusing together to form the moon.
What is an Umbra?
The full shadow of the moon during a solar eclipse, people in this spot will see a full eclipse
What is a Penumbra?
The edge of the shadow of the moon during a solar eclipse, people in this spot will see partial eclipse
What is the moons core like?
The moon has a solid Iron-rich inner core, and a liquid Fe-rich outer core.
What is the dark side of the moon?
The moons rotation is fixed in that one side of the moon would always face Earth. We only ever see the near side of the moon and never the “dark side”. It has a rotation every 27.3 days & orbits every 27.3 days.
How much of the moon do we see?
about 59% thanks to a process known as libration which is the moon wobbling.
How far apart are the moons phases and why?
they are about 29 1/2 days apart because the extra time is needed for the moon to overcome the extra movement caused by the Earth’s revolution around the sun.
what are the smooth plains called on the moon?
marias
who gave the marias their name?
Galileo
what are the non smooth parts of the moon referred to as?
Hills and uplands
is the moon volcanic or tectonic?
no it is tectonically and volcanically dead
What created the highlands?
meteoritic impact
how many craters are on the moon?
at least 8 million
how many craters on the moon have a larger diameter than 1km?
300 000
why does the moon have so many craters and the earth have so few?
The earth has a protective atmosphere that burns up more than 99.99% of all meteoroids that strike it. The earth also has tectonic plates that churn over new land, and erosive forces that destroy land features.
What is a Lunar Eclipse?
A lunar eclipse is when the moon passes through the shadow of the earth created by the sun, completely covering the moon, stopping it from shinning.
What causes tides?
The gravity of the moon orbiting the earth
How many times a day do tides occur?
twice
Would evolution had taken a different path without the moon? if so why?
yes it would have, because the tides created by the moons gravity make for some harsh living environments that only strong life would have been able to survive, strong enough life to eventually make their way to the land.
When did man first step on the moon?
July 20/21 1969 depending on where you were in the world
What was the name of the first spacecraft that took man to the moon?
Apollo 11
Who was the first man to step foot on the moon and who was the second?
Neil Armstrong, and Buzz Aldrin
How long did Neil and Buzz do the moonwalk?
2 hours and 20 minutes
How many successful Apollo missions were there in total and what were their mission numbers?
6 in total, and they were 11, 12, 14, 15, 16 & 17
What is the average distance to the moon?
384 000, with the perigee at 357 000 and the apogee at 406 000
When does the full moon occur?
When the moon is on the far side of the earth away from the sun.
When does the new moon occur?
When the moon is closer to the sun than the earth.
