Science In Action Unit E Topic 1 & 2 Quiz Flashcards
Solstice
It comes from the Latin words sol meaning sun and stice
meaning stop
June 21: Summer solstice, the longest day of the year
December 21: winter solstice, the shortest day of the year
Ability to predict the beginning of summer and winter
Huge monuments built to honour these changes
They used only their naked eye to make these predictions but were highly
accurate
Equinox
Comes from the Latin eqi meaning equal, and nox
meaning night
Day and night are equal
March 21: Spring equinox
September 22: Fall equinox
Stonehedge
Southern England
Arranged in concentric circles
Enormous stones mark summer and winter solstices
Placed to line up with the movements of the sun
Different Astronomical Devices
Sundial:
A stick in the ground
Used for over 7000 years
Where the shadow is pointing can help us tell time
Merkhet: Egyptians invented this device to predict the movements of the stars
Quadrant: Egyptians also invented this to measure a star’s height above the horizon
Astrolabe: Arabians used this tool to make accurate charts of the stars
Crodd-Staff: 14th-century astronomers used it to measure the angle between the moon and any stars
Telescope
Revolutionized astronomy
More of the night sky was visible than ever before Learn about our neighbours in the solar system
History:
Over 500 years after the invention of the first telescope
We have optic and radio telescopes, as well as space
based telescopes
Can see much farther and see more objects
Units of Distance
Astronomical Units (AU):
Used for measuring distances within our solar system
Equal to the average distance between the centre of
the earth to the centre of the sun (149 599 000 km)
Describe planets in relation to the sun
Light-Years:
Astronomical units are too small if we’re talking about objects outside of our solar system
The distance that light travels in one year
Approximately 9.5 TRILLION km
The next closest star to Earth is Proxima Centauri, 4 light-years away
Star Temperatures
Blue Colour = Hottest
Red Colour = Coolest
Life Cycles of “Sun-like Stars”
Nebula< SUN- LIKE STARS< Red giant< White Dwarf< Black Dwarf
Life Cycles of “Massive Star”
Nebula< MASSIVE STARS< Red supergiant< Supernova< Neutron Star or Black Hole
Hertzsprung-Russell (H-R diagram)
Compared surface temperature of stars to how bright they are (luminosity)
Stars fall into distinct groupings
Our sun belongs to the middle grouping in the diagram called the main sequence
90% of all stars fit in this group
Constellations vs. Asterism
Groupings of stars, and patterns in the night sky
88 constellations recognized by the International
Astronomical Union
Asterisms: unofficial groupings of stars
Ex. Ursa major= constellation, Big Dipper = asterism
Elliptical
Flattened “oval”
Is the shape of the predictable pathway that celestial bodies orbit on.
A type of galaxy including irregular + elliptical
Blackhole
Highly dense remnant of a star
Super strong gravity
No light can escape from inside the black hole
Invisible to telescopes
Material near a black hole becomes hot and bright
Astronomers know of blackholes because of that
Neutron Star
Rapidly spinning object
About 30km in diameter
A teaspoon of neutron star is so dense it would weight 100 000 t
Nebula (Singular)
Vast clouds of gas (mostly hydrogen) and dust in space, where stars form
More than 1 nebula is called “nebulae”
Celestial Sphere
Large imaginary sphere of sky around the earth
Solar Wind
Charged particles released by the sun
Earth is protected by it’s magnetic field
Protoplanet Hypothesis- Forming a
Solar System
A cloud of dust and gas in space begins swirling
Most of the material accumulates in the center- forms the sun (OVER 90%)
The remaining material accumulates in smaller clumps forming the planets
Planets
Each planet has its unique features
Divided into two planet groups: inner planets and outer planets
Technology has allowed us to learn about our nearest neighbors in space
Names
Mercury My
Venus Very
Earth Educated
Mars Mother
Jupiter Just
Saturn Served
Uranus Us
Neptune Noodles