The Universe - Space/Stars/Solar System Flashcards
What causes the seasons?
The tilt of the Earth
What are tidal forces?
When gravity pulls one part of an object away from its center of mass
What shape is the Earth?
A slightly oblong sphere (oblong spheroid)
Why do we only see one face of the Moon?
The Moon only spins once as it goes around us, which always shows us one side.
Which is the highest tide: a spring tide or a neap tide?
Spring tide - caused by the Sun and Moon pulling in the same direction.
What are the 8 phases of the Moon?
Waxing: New, Crescent, Quarter, Gibbous.
Waning: Full, Gibbous, Quarter, Crescent.
What process takes place in the Sun’s Core and turns hydrogen into helium?
Nuclear Fusion
What are the sections of the Sun?
The Core, the Radiative Zone, the Convection Zone, the Photosphere, and the Corona.
What do we call the incredibly fast rush of particles carrying light and heat energy away from the Sun and into the Solar System?
Solar Wind
How hot is the Sun’s core?
around 15,000,000 degrees Celsius
What is the Big Bang Theory?
All matter in the Universe exploded out from a infinitely dense point called the singularity.
What are the two Eras of the Big Bang Theory called?
The Radiation Era and the Matter Era
What were the first two elements that formed during the Matter Era?
Hydrogen and Helium
What type of celestial bodies created the rest of the elements?
Stars
What are the four terrestrial planets?
Mercury, Venus, Earth, Mars
What are the four gas giants?
Jupiter, Saturn, Uranus, Neptune
Which planets are over a billion miles away from the Sun?
Uranus and Neptune
Which planet has the hottest surface temperature?
Venus
Which planet has the most moons?
Saturn (82)
Which planets have no moons?
Mercury and Venus
What kind of star is our Sun?
a yellow dwarf
What will happen to our Sun as it nears the end of its lifespan?
It will become a red giant and be both larger in size and cooler in temperature
What are the three shapes of galaxies?
Spiral, elliptical, and irregular
What shape is our galaxy?
Spiral
What is a nebula?
An incredibly large cloud of gases (mostly hydrogen) that has the potential to collapse inward and form the beginnings of a star
What is a dark nebula?
A nebula with a combination of gases that blocks light from passing through it.
What is the name of the diagram we use to measure the life and characteristics of stars?
a Hertzsprung-Russell diagram
What is a main sequence star?
a star that is currently in its “adult” life; fully developed and able to resist gravity through hydrogen fusion alone
What happens to a low mass star when it dies?
It sheds its outermost layers and becomes an Earth sized white dwarf, far less powerful and hot as it eventually burns out.
What happens to a high mass star when it dies?
It usually explodes into a supernova, a massive explosion
Which color of main sequence star burns hotter: blue or red?
Blue. The blue color indicates a high rate of energy coming from its fusion reaction. Red indicates a downward shift in energy and temperature
What is a constellation?
A group of stars that humans have drawn imaginary lines between to form images
What are the zodiac signs?
13 constellations that are associated with different times of the year.
True or False: You can see all constellations at all times of the year from all locations on the planet.
False: Most constellations are seasonal and most are only visible in one hemisphere of the world (ex. Southern Cross is only seen in the Southern Hemisphere)
What is the difference between an asteroid and a meteor?
Asteroids orbit the Sun; meteors orbit the Earth
What is the difference between asteriods/meteors and comets?
their composition is different; asteriods/meteors are rocky and metallic; comets are mostly ice and gas with a little rocky material
What’s the difference between meteors, meteoroids, and meteorites?
Meteoroids= in space/orbit
Meteors= falling through Earth’s atmosphere
Meteorites=crashed into Earth’s surface
What was the Space Race?
the competition between the US and the Soviet Union to be the first to explore space.
Who launched the first successful satellite?
Soviet Union (USSR)
Who had the first spacewalk?
Soviet Union (USSR)
Who had the first man to walk on the Moon?
USA
What are the main health hazards for humans traveling in outer space vs life on Earth?
lack of oxygen, lack of heat, and lack of air pressure
What is the main purpose of a space suit?
to keep the astronaut pressurized and to provide breathable oxygen
What is the study of the Universe called?
cosmology
Why is cosmology (and its smaller sub-category astronomy) so fascinating?
Because it constantly shows us just how much bigger and more complex the Universe is than our own small lives here on Earth. There’s always more to learn!
What are the two types of eclipse?
lunar and solar
What is a lunar eclipse?
When Earth’s position blocks light from reaching the moon
What is solar eclipse?
When the moon’s position blocks our view of the sun
What is a annular solar eclipse?
When the moon blocks our view of the sun, but it’s in its furthest position from the Earth, so we can still see the outline of the sun’s photosphere around the moon.
What is the area of direct shadow cast on the Earth during a solar eclipse called?
the umbra
What are the more lit/still shadowed areas around the umbra called?
the penumbra
