astro exam #1 and #2
What is the critical "radius" that an object in space must have to be considered spherical in its shape?
350 kms
What is the likely cause of Venus' retrograde rotation?
An impact with a large planetessimal long ago in its past.
How do astronomers think that the interior of Saturn is heated?
Condensation of Helium within its atmosphere.
What are seeing conditions
Image quality due to turbulence within the atmosphere
Which of the following best describes Titan?
It can rain methane from its atmosphere.
What is a telescope's resolving power?
It's ability to distinguish two objects as being separate.
What is the ordering of planets according to their size, starting with the smallest and ending with the largest?
Mercury, Mars, Venus, Earth
Which of the following gives the correct order of planets, starting with the planet closest to the Sun and ending with the planet further from the Sun?
Mercuy, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Why have we found so many objects in the Kuiper Belt in the last three decades, but not before then?
Most objects in the belt are small and at Pluto/Neptune's distances reflect little sunlight. So to find them astronomers needed to use super sensitive detectors used with large telescopes. They also needed to be very patient to get effective/correct surveys of the correct parts in the sky to see it. So thats why now because we have newer and better technology we are able to find more objects in the Kuiper belt.
The Earth's atmosphere today is composed of approximately 78% __________, 21% __________, and much less than 1% __________.
Nitrogen Oxygen Carbon Dioxide and other gases
Would it be safe to send a manned-mission to Venus? Why or why not?
No the pressure is too high
Would using a compass to navigate on the Moon work? Why or why not?
No, due to the Moon having too weak of a magnetic field due to its small iron core.
Where does most of the oxygen in Earth's atmosphere come from?
Photosynthesis from plant life
How do the rings of Saturn compare to the rings of Jupiter?
Saturn's rings are made primarily of water-ice whereas Jupiter's rings are primarily made of carbon compounds.
You have a jar containing hydrogen gas that, when heated, produces an emission-line spectra. If more hydrogen gas were to be added to the jar, and then re-heated, what effect would this have on the emission-line spectra?
The emission lines would become brighter
How did comet collisions with the Earth contribute to the Earth's initial atmospheric composition?
The ices within comets vaporized upon impact with the Earth's surface ???
What is the source of the Earth's magnetic field?
The motion of the liquid metal in the Earth's outer core.
What conclusion can be drawn, about the motion of a star, if it shows now Doppler-shift in its spectra?
The star might be moving perpendicular to the telescopes line of sight
What makes the Apollo asteroids unique?
Their orbit intersects Earth's orbit, making them dangerous.
The Moon's average density is 3.3 g c m 3. What does this imply about the amount of metal in its interior?
There must be a small iron core with a small liquid component.
An advantage of using radio telescopes is that they can make observations during the day and at night.
True
Glass lenses are an improvement over human eyes, in terms of light-gathering, because their larger sizes allow more light to be gathered into the telescope.
True
Why is the light the reaches the surface of Venus orange/yellow in color?
Venus' atmosphere absorbs these orange/yellow colors of light from the Sun.
Mercury is the closest planet to the Sun, but why is Venus' surface temperature higher than Mercury's?
Venus' thick atmosphere of Carbon Dioxide created a Greenhouse Effect which keeps the planet perpetually warm.
Which of the following regions of the electromagnetic spectrum is completely blocked by the Earth's atmosphere?
X-rays
What type of spectra is produced when sunlight passes through Earth's atmosphere?
absorption line
What technology can astronomers use to counteract poor seeing conditions?
adaptive optics
Where are most asteroids located within our solar system?
between orbits of mars and jupiter
Mercury and the Moon are very similar to each other in regard to their atmosphere. Which of the following is a valid similarity?
both have thin atmospheres due to their weak gravity
What is most widely accepted theory about the Moon's formation?
collision theory
Which type of spectra has the brightness of its lines change smoothly with color, with all colors of the rainbow being present?
continuous
Which of the following is a type of weather that Mars has in common with the Earth?
dust storms
A comet spends most of its time, in orbit around the Sun, nearby its perihelion position.
false
Within the asteroid belt, its inner region consists mainly of C-type asteroids whereas the outer region consists mainly of S-type asteroids.
false
What property of nucleus fission allowed scientists to calculate the age of the Earth?
half-life
A mountain-top is an ideal location for astronomy observatories and telescopes because it
is above much of the atmosphere and man-made sources of light.
Is it possible to land a spacecraft onto the surface of Jupiter? Why or why not?
no since jupiter has no solid surface
Is the Earth a perfect sphere? Why or why not?
no since the earth buldges along the equator
What is the name of the largest volcano in our solar system? Where is it located?
olympus mons on mars
On which tectonic plate are we currently located, here at Irvine Valley College?
pacific
What is unique about the secondary mirror in a telescope with adaptive optics?
perfect sphere ???
What is the source of the vulcanism that can be clearly seen on Io's surface?
strong tidal forces from jupiter
Choose the answer below which best fills in the blanks to the following statement: Compared to the __________ planets, the __________ planets have __________ .
terrestial, jovian, many satelites
How does the density within Jupiter's atmosphere change as you descend deeper into it?
the pressure increases
What makes the Trojan asteroids unique?
they all lie along jupiters orbit
Diffraction is an inherent problem in all telescopes due to the wave behavior of light as it enters a telescope's aperture.
true
The leading theory as to why Uranus' angle of inclination is so large involves an impact with a large planetessimal long ago in its past.
true
The primary reason why the Moon has been so thoroughly explored by scientists and astronauts is that it's the closest object to the Earth, and therefore easier to access and observe.
true
When the Shoemaker-Levy 9 comet passed through the Roche Limit of Jupiter it was fragmented via differential gravity.
true
Imagine that a meteorite studied by astronomers in 1980 has 100 atoms of radioactive Potassium. When that same meteorite fragment is studied again, several years later, it is discovered that there are now only 25 atoms of radioactive Potassium. In terms of nuclear fission, how much time has elapsed?
two half lives
what is the great red spot
vortex of spinning gas in jupiters upper atmosphere