Flashcards in Lecture 5 Deck (42):
Which moon was found to have water plumes?
What does Europa's geology look like?
Saltwater ocean under a crust of ice
How are scientists planning on observing Europa's plumes?
By taking photos during Europa's transit across Jupiter so that the plumes are backlit.
What are the three pieces of tech that a mission to Europa would carry?
A UV Spectrometer, a mass spec, and a dust analyzer
What is a another moon that exhibits the behaviour of Europa?
What did the ancients think the sun was made of?
What did pre-modern scientists think kept the sun warM?
Who discovered radioactive decay?
Becquerel, Rutherford, the Curies
What is radioactive decay?
Energy (in the form of alpha, beta, and gamma particles) given off by the nucleus
What keeps the sun burning?
How does the sun keep from collapsing in on itself?
It has a gravitational equilibrium
What is gravitational equilibrium?
The gravity pulls in just enough that the outward rush of gas is held back, so the sun maintains its shape.
What is needed for fusion to occur?
Extremely high temperatures, an electromagnetic force and quantum tunneling.
How did gravitational contraction contribute to nuclear fusion?
It provided the heat necessary as the sun was FORMING
How many protons are necessary for fusion of 1 He to occur?
What else is expelled through fusion?
2 gamma rays, 2 positrons, 2 neutrinos, energy
How does the virial theorem work?
As energy is used to push a satellite further out of orbit, the satellite orbits slower
How does virial theorem apply to the sun (solar thermostat)?
As nuclear fusion heats and speeds up, the sun expands and cools, slowing the fusion down; ad infinitum
How does convection affect photos?
It allows them to reach the surface faster
How are kinetic and potential energy related?
Etotal=Ekin + Epot
How are total energy and potential energy related?
What are the three methods we can use to know what goes on inside the sun?
Mathematical models, observing solar vibrations, observing solar neutrinos
Approximately how long is the sun's spin?
about a month
What is the outermost aspect of the sun's structure?
the solar wind
What is solar wind?
Charged particles escaping
What is layer is just below the solar wind and above the chromosphere?
What is the corona?
It is the super hot, low density outer layer of the sun that emits x-rays
What is the layer that is just below the corona but above the photosphere?
What is the chromosphere?
Slightly cooler than the corona, it emits alpha particles and UV radiation
What is the layer below the chromosphere and above the convection zone?
It is the photosphere
What is the photosphere?
It is what we see as a "surface", and it is the origin of most photos
What is the layer below the photosphere but above the radiation zone?
The convection zone
What is the convection zone?
The area where hot gas rises and cool gas falls
What is the layer below the convection zone but above the core?
The radiation zone
What is the radiation zone?
The zone where energy moves outward as photons
What is the innermost layer?
What is the core?
the hottest area where fusion occurs
What are the conditions of a sunspot?
A cooler spot where the magnetic field is twisted
What is the zeeman effect?
Used to measure sunspots, the zeeman effect shows how spectral lines are split in areas that are sunspots because of the magnetic fields
What causes prominences or filaments?
Magnetic field lines gone awry
Why does the corona not appear always uniform?
It only appears where magnetic fields trap hot gas