Jazzlyn Flashcards
Understand and describe how the apparent motion of stars depends on the Earth’s revolution, rotation and your location.
Almost all the motions of the sky are due to motions of the Earth. The main motion is the rotation of the Earth. We spin around once in approximately 24 hours - that is why we see the stars and Sun appear to move in about 24 hours.
Explain the nightly apparent motion of both circumpolar and seasonal stars:
Circumpolar stars are always visible at night depending on where you live, rotate around a pole.
Seasonal stars are more towards the equator and come throughout seasons.
Explain how the moon exhibits phases:
How the sun lays light on the moon and where at we are on earth creates phases of the moon.
Describe the geometry required for lunar and solar eclipses:
LUNAR: Earth casts shadow on Moon. SOLAR: Moon casts shadow on Earth.
Describe Kepler’s three laws. To what do they apply?:
1: Each planet moves around the sun in an elliptical orbit and the sun is at one focus.
2: The orbital speed of each planet is:
** Faster when it’s closer to the sun.
** Slower when it’s farthest from the sun.
3: Determines the length of a planet’s year.
The length of a planet’s year is proportional to the size of its orbit, or in other words… The further a planet is from the sun, the longer its year is.
What does the force of gravity depend on:
The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them. This means that the force of gravity increases with mass, but decreases with increasing distance between objects.
Life as we know it requires what to exist?:
Energy input (Preferably sunlight)
Water
Carbon
Atmosphere?
What is the most realistic way to find other life in the universe? Why?:
Look for chemical signatures of life such as Water Co2 Methane and Oxygen
Discuss two indirect ways extrasolar planets are found.
Transit: This method detects distant planets by measuring the minute dimming of a star as an orbiting planet passes between it and the Earth.
Radial Velocity method:
Detection of the “wobble” of light as the planet pulls the parent star.
What are the attributes of the most easily found exoplanets?:
Extremely large and always near stars.
Describe two ways we know what’s going on in the interior of the sun:
For the sun, we make measurements of the kinds of light it produces, and with special instruments called spectroscopes we can examine how atoms in the sun are moving. We can very accurately measure the temperature of the sun, and the way different parts of it are heated. Recently, astronomers discovered that the sun actually ‘rings’ like a bell, and by studying the different kinds of ways that the sun’s surface is vibrating, this lets us probe deep into the inside of the sun, much like earth quakes on the earth let us probe the inside of the earth. The way the sun rings, tells us that it is not a smooth ball of gas inside, but has several different layers.
Explain the basic features of a sunspot
Sunspots are “cool” regions, only 3800 K (they look dark only by comparison with the surrounding regions). Sunspots can be very large, as much as 50,000 km in diameter. Sunspots are caused by complicated and not very well understood interactions with the Sun’s magnetic field. the average duration of a sunspot is 11 years.
Describe solar activity and its effects (Solar cycle, sunspots, CMEs, Auroras):
Solar cycles have an average duration of about 11 years. They have been observed (by changes in the sun’s appearance and by changes seen on Earth, such as auroras) for hundreds of years. Solar variation causes changes in space weather, weather, and climate on Earth. It causes a periodic change in the amount of irradiation from the Sun that is experienced on Earth.
Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. They correspond to concentrations of magnetic field that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.
A coronal mass ejection (CME) is a massive burst of gas and magnetic field arising from the solar corona and being released into the solar wind, as observed in a coronagraph.
Coronal mass ejections are often associated with other forms of solar activity, most notably solar flares or filament eruptions, but a broadly accepted theoretical understanding of these relationships has not been established. CMEs most often originate from active regions on the Sun’s surface, such as groupings of sunspots associated with frequent flares.
Aurorae are caused by cosmic rays, solar wind and magnetospheric plasma interacting with the upper atmosphere
Discuss differences and similarities between terrestrial planets and Earth including differentiation, atmosphere, number of moons, composition and geological activity:
Mercury - Surface layer silicate rock, mantle of silicate rock, iron core. No moon, No atmosphere.
Venus - crust/solid silicate rock, mostly basalt, mantle/solid silicate rock, outer core/liquid iron and nickel, inner core/ dense solid iron and nickel. No moon. Heavy atmosphere.
Earth - crust/solid rock, mostly basalt, mantle/solid silicate rock, outer core/liquid iron and nickel, inner core/dense iron and nickel. One moon.
Mars - crust/iron rich basalt rock, mantle/solid silicate rock, core/partially liquid iro, nickel and sulfur. 2 moons, Phobos, Deimos
Discuss differences and similarities between Jovian planets and Earth including overall color, storms, composition, number of moons and rings:
all planets are made up of hydrogen and helium. Neptune and Uranus gain their blue color from methane. All the jovian planets have strong winds and storms.
