U2 Discovering New Worlds Flashcards
How the Sun Works, Lide Cycle of Stars, Planets and Orbits
red shift
the observation that as an object moves away from us, its wavelength is stretched out and moves towards the red end of the spectrum
cosmic background radiation
The “afterglow” or radiation left over from the Big Bang; found throughout the universe
comet
chunk of rock and ice orbiting from the outer solar system to near the Sun
meteor
streak of light seen when a space rock enter’s Earth’s atmosphere and starts burning up (sometimes referred to as “shooting stars”); if it doesn’t completely burn up in the atmosphere and actually hits the Earth it is called a meteorite
asteroid
rocky/metallic object orbiting the Sun between Mars and Jupiter in the “asteroid belt”; these can leave this orbit and move through the universe
supernova
when a very large star dies and explodes
gravity
a force between objects that pulls them together; will increase with mass and decrease with distance
nuclear fusion
the combining of 2 lighter elements (hydrogen) to form a heavier element (helium); it is the source of power for stars and release a lot of energy
exoplanet
a planet outside our solar system
revolution
moving around an object in an orbit (such as the Earth revolving around the Sun)
rotation
spinning on an axis
luminosity
the brightness of a star
eccentricity
a measurement that tells the shape of an orbit (distance between foci/length of the major axis); the closer the measurement is to 1 the flatter the orbit and the close to 0 the more circular the orbit
ellipse
an oval shape
main sequence
the most stable time for a star; it spends most of its life in this stage
life cycle of a star
the predictable stages of a star’s life
white dwarf
the final stage for our Sun; dead star
black hole
created when a very large star explodes
neutron star
when a very large star explodes but is not big enough to form a black hole
nebula
gases in space that appear to form a cloud; will be the leftovers (remnants) and a star explosion (supernova); may eventually contract to form a star
What galaxy are we in?
Milky Way
star system
the planets and objects that orbit a star; the star system is named after the star Ex: Betelgeuse System, Solar System, Polaris System
major axis
the diameter of an ellipse at its widest point
aphelion
the part of an orbit where the object is farthest away from what it is orbiting around
perihelion
the part of an orbit where the object is closest to what it is orbiting around
terrestrial planets
planets that have a rocky surface; in our solar system they are located closest to the Sun: Mercury, Venus, Earth, and Mars
jovian planets
the gas giants; in our solar system they are located farthest from the Sun: Jupiter, Saturn, Uranus, Neptune
compared to the solar system, the universe is
older, larger, and contains more stars
What is located at one of the foci of an orbit?
the star the object is orbiting around
When did our Solar System form?
4.6 billion years ago
When did Venus form?
4.6 billion years ago
Compared to the terrestrial planets, the Jovian planets are
less dense and more mass
What are the Jovian planets?
Jupiter, Saturn, Uranus, and Neptune
What are the terrestrial planets?
Mercury, Venus, Earth, and Mars
Explain why Pluto and its five moons are considered to be part of our solar system
— Pluto and its five
moons revolve
around the Sun.
— All go
around/orbit the Sun.
Identify the name of Pluto’s moon that most likely has an orbit farthest from Pluto. Explain how the data indicate that this moon’s orbit has the greatest distance from Pluto.
— Hydra has the
longest period of
revolution.
— As a moon’s
distance from Pluto
increases, the time
to make one
revolution also
increases.
— Hydra travels the
greatest distance in
its orbit because it
has the longest
period of revolution.
Describe the shape of the orbit of Pluto and the orbits of its five moons.
— elliptical
— The orbits are
eccentric.
— The orbits are
nearly, but not
perfectly, circular.
— oval
— Pluto’s orbit is
elliptical, and the
moons of Pluto have
a more nearly
circular orbit.
Which is a possible surface temperature of this star at point 2? (see figure):
A) 3000 K
B) 5000 K
C) 7000 K
D) 10,000 K
C
Between points 1 and 3, this star is visible to observers on Earth because it emits light energy. This energy is released by the process of nuclear fusion when:
A) dust collides with the star
B) dust is broken apart by radiation
C) lighter elements combine to form heavier elements
D) heavier elements are broken down to form lighter elements
C
