Term
| the most comment elements in the universe are? |
|
Definition
|
|
Term
| what elements account for 98% of the total mass of the universe? |
|
Definition
|
|
Term
| name the nine planets of our solar system - in correct order outward from the sun |
|
Definition
| mercury venus earth mars jupitar saturn uranus neptune pluto |
|
|
Term
| in august 2006, astrophysicists gathered at a conference in Prague, Czech Republic and made a new definition of what constitutes a "major planet." Because of their decision, what planet has been demoted to "minor planet" status? |
|
Definition
|
|
Term
| the most probable theory for formation of the sun & solar system is that |
|
Definition
| the sun and planets slowly condensed to their present form from a collapsing, rotating nebula of gas and dust cloud |
|
|
Term
| the process of accretion in planetary formation is |
|
Definition
| the slow accumulation of solid particles by gravity and collision into larger, solid objects |
|
|
Term
| where is the asteroid belt located in our solar system? |
|
Definition
| most asteroids orbit the sun in a belt about 1.5AU wide between orbits of mars and jupiter |
|
|
Term
| the solar system contain heavy elements, formed from an earlier generation of stars. True or false? |
|
Definition
|
|
Term
| strong evidence for the existence of planetary systems in the process of formation around other stars comes from |
|
Definition
| periodic wobbling of the positions and spectral line displacements of several nearby stars |
|
|
Term
| in theory, where did all of the hydrogen in the universe come from? |
|
Definition
|
|
Term
| there is very little hydrogen or helium in the inner part of the solar system today. We believe the reason for this is that |
|
Definition
| intense radiation from the early sun drove the light elements out of the inner solar system |
|
|
Term
|
Definition
| comets are chunks of rock and ice. beyond orbit of neptune lies hundreds of millions of these objects. |
|
|
Term
|
Definition
| a belt of comets that abound in the million in orbit past pluto out to 50au from sun |
|
|
Term
| color of a body is related to increasing heat; how? |
|
Definition
| changes through orange to white then blue |
|
|
Term
| how do we know chemical make-up of a star? |
|
Definition
| the science of spectroscopy idetification of atoms by the appearance of their spectra (bright and dark patterns of lines) as separated by a diffraction grating in the instrument called a spectrocope |
|
|
Term
| we plot the intensity of the radiation emitted from an object at a certain temperature versus its wavelength. as we increase the temperature, the wavelength at which the spectrum peaks becomes shorter and shorter. this is an example of |
|
Definition
|
|
Term
|
Definition
| as temperature increases, wavelength emission peaks become shorter and shorter |
|
|
Term
| what is a diffraction grating? |
|
Definition
| a piece of glass or plastic w/ thousands of etched parallel grooves |
|
|
Term
| a diffraction grating is the key component of what instrument? |
|
Definition
| the spectroscope, an instrument for splitting light rays that produce spectra (patterns of light seen when an element is vaporized into a gas) |
|
|
Term
| the dark absorption lines in the solar spectrum are caused |
|
Definition
| by a cooler layer of gas overlying the hot solar surface, which contains many elements including hydrogen, helium, magnesium, calcium, iron, etc. |
|
|
Term
| when astronomers look for evidence of hydrogen gas in the spectra of the Sun, or other stars, the positions of the spectral "lines" due to hydrogen |
|
Definition
| will always be in the same characteristic pattern as seen in the laboratory, a pattern unique to hydrogen, but will appear black due to absorption on the cool atmosphere of the air |
|
|
Term
| what does it mean to say - "hydrogen has an emission spectrum"? |
|
Definition
| when any element is vaporized here on Earth it will emit bright lines of color that are unique for each element |
|
|
Term
| what evidence do we have that the sun contains the element, iron? |
|
Definition
| solar spectra shows absorption in spectral lines that are characteristic of iron & are unique to it |
|
|
Term
|
Definition
| visible "surface" layer of the sun |
|
|
Term
| heated interstellar hydrogen gas, near a hot star, will still emit |
|
Definition
| spectral lines characteristic of hydrogen |
|
|
Term
| in our sun, a supergranule is? |
|
Definition
| an enormous region of rising & falling chromopheric gas.. A typical supergranule gas bubble has a diameter slightly larger than the Earth |
|
|
Term
|
Definition
| dim layer of less dense gas ABOVE the photosphere. its the middle layer of 3 atmosphere layers of the Sun |
|
|
Term
|
Definition
| splitting of spectral lines emitted by atoms within a magnetic field |
|
|
Term
|
Definition
| gas ejected from the corona, breaking force of the sun's gravity & becomes a bubble in space containing the solar system & protecting us from other radiation entering our solar system; called the Heliosphere |
|
|
Term
|
Definition
| protective region containing the sun and planets cradled by the solar wind, which prevents penetration by much of the radiaiton from outside our solar system |
|
|
Term
| what is the name of a small jet of rising gas in the chromosphere of the Sun? |
|
Definition
|
|
Term
|
Definition
| uppermost atmosphere of the sun |
|
|
Term
| most of the elements beyond hydrogen & helium in the periodic table in our sun and solar system most probably originated |
|
Definition
| from fusion reactions in the centers of earlier stars |
|
|
Term
| most of the weight of our bodies comes from heavy elements such as carbon and oxygen. This fact immediately tells us that |
|
Definition
| solar system didn't form directly from material created by the Big Bang |
|
|
Term
|
Definition
| cooler, darker regions of the sun's "surface" |
|
|
Term
| what main physical characteristic do sunspots possess? |
|
Definition
|
|
Term
| what is the sunspot cycle? |
|
Definition
| sunspots come in and go in a 11 year cycle |
|
|
Term
| how hot is the sun? on its surface? in its interior? |
|
Definition
| 5,800K on surface, 1.5 million degrees kelvin in core |
|
|
Term
| thermonuclear fusion is.. |
|
Definition
| combining of light nuclei w/ heavy nuclei w/ resultant release of energy |
|
|
Term
| what two elements form the basis of thermonuclear fusion? |
|
Definition
|
|
Term
| what is thermonuclear fusion? |
|
Definition
| fusion of hydrogen into helium, at temperature above 1 million degrees Kelvin, w/ resultant release of EM radiation |
|
|
Term
| the energy source for the Sun is? |
|
Definition
| thermonuclear fusion of H & He w/ resultant release of energy |
|
|
Term
| most likely mechanism for formation of solar system? |
|
Definition
| is it slowly condensed from a cloud of gas & dust |
|
|
Term
| how can we tell if a star contains a particular element? |
|
Definition
| examine the spectra of light emitted by that star |
|
|
