Solar System Flashcards
Order of planets
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune (MVEMSUN)
Mercury
little atmosphere, smallest, rocky
Venus
Thick, toxic atmosphere, hottest
Earth
Balanced atmosphere, water
Mars
Can’t support liquid water, little atmosphere
Jupiter
Largest, hydrogen and helium, dozens of moons
Saturn
Ring system of ice and rock, thich atmosphere, lots of moons
Uranus
Methane makes it blue, ice giant, rotates on side
Neptune
Fast winds, large, similar to uranus
Terrestrial planets
Mercury, Venus, Earth, Mars
Gas Giants
Jupiter, Saturn, Uranus, Neptune
Kuiper Belt
Lays just outside neptune’s orbit, rotates in prograde, ice and has dwarf planets, on same plane as planets
Prograde
Direction that the planets orbit the sun, with rotation of sun when looking at north pole of sun
Pioneer 10/11
1972/1973, first missions to explore outer solar system, first to get close to jupiter and saturn
Voyager I/II
1977, all planets were lined up, amazing opportunity to get gravity assists from planets, Voyager II first to see uranus and Neptune, both left solar system
Oort Cloud
Theoretical, outside of Kuiper belt, furthest edge of solar system, 2,000-5,000 AU from sun, may go up to 100,000 AU, long-period comets best support theory, complete sphere around solar system
Planet Rotation
most planets spin in prograde (counter-clockwise), venus and uranus rotate in retrograde (clockwise), most moons orbit parent bodies in prograde, uranus rotates on side 98 degrees
Orbital Plane
Planet’s orbit the sun within the plane of the elliptic, each planet has a slight tilt, all orbit on the same-ish level
Comparing Planet’s masses
Jupiter is most massive, venus and earth have similar masses (twins), Uranus and Neptune are similar, mars is 1/10 earth’s size
Comparing Planet’s Diameters
Earth and Venus are sisters in diameter, uranus and neptune are similar, Jupiter is largest in diameter
Comparing Planets densities
Terrestial planets are more dense (around 5 g/cm^3), Gas giants are less dense (around 1.5 g/cm^3)
Planetary Tilts
All planets tilt at different angles, venus is upside down causing retrograde rotation, slight tilt of 25 degrees gives seasons, uranus tilts at 98 degrees giving extreme seasonal variation
Earth’s tilt
23.5 degrees
Rotational Periods
Jupiter and saturn spin fast (10 hrs.), Earth and mars rotate at the same speed, Mercury and Venus are SLOW (thousands of hours), venus’ year is shorter than its day, uranus and Neptune (18 hrs.)
Why some planets do/don’t have atmosphere
depends on molecular speeds, high temps make faster speeds and allows molecules to escape planet’s gravity (Escape velocity), need good combo of escape velocity and temp
Observations of the Solar System
