How long does it take light to travel a distance of one light year?
One year or about pi x 107 seconds.
• What is the unit that we use to measure distances in the solar system?
The astronomical unit or AU is very convenient.
• If Earth rotated on its axis twice as fast as it currently does, but its motion around the Sun stayed the same, then
the night would be half as long
• A long thin cloud that stretched from directly overhead to the western horizon would have an angular size of
6. In December we would see the Sun in the direction of the constellation(s)...
Sagittarius and Capricorn
If the Moon's orbit around Earth were a little larger, solar eclipses would be
more likely to be annular
What two pieces of information are needed to determine the diameter of a far away object?
Distance and angular size
The seasons are caused by the precession of the Earth's
The solar day is longer than the sidereal day
The most northern location on Earth where the Sun can be seen directly overhead at noon is called
The Tropic of Cancer
What is the approximate position of Polaris on the Celestial Sphere?
Approximately RA = 2h 30 min, Dec = 89 degrees
The Age of Aquarius refers to what?
It means that in the future the vernal equinox will occur in a direction in line with the constellation Aquarius due to the precession of the Earth's axis of rotation.
5. When a thin crescent of the Moon is visible just before sunrise, the Moon is in its
you put an apple 10 m away from your eye in line with the moon, what do you predict?
It would "eclipse" the moon.
• The alpha star in a constellation is (as seen from Earth):
The brightest star in a constellation as seen from Earth.
• A major flaw in Copernicus's model was that it still had
• An asteroid with an orbit lying entirely inside Earth's orbit
has an orbital semimajor axis of less than 1 AU
• Galileo's observations of Venus demonstrated that Venus must be
Orbiting the Sun
• showing the motion of a ball near Earth's surface, depicts how gravity
Causes the ball to accelerate downwards
• How long would a radar signal take to complete a round trip between Earth and Mars when the two planets are 0.7 AU apart?
about 11.6 minutes
• The light coming from a star has a dominant wavelength of 1000 nm. How hot is the star in degrees Kelvin?
• What is the dominant wavelength in nanometers of the light coming from a very hot star (about 29,000 K)?
• The H-alpha spectral line 656 nm coming from a distant star appears at a wavelength of 100 nm in the spectrometer. What can we say about the star?
It is moving towards us at 85% the velocity of light
• Comet X orbits the Sun every 10 years. What is the average distance (semi major axis) of the comet from the sun?
• The temperature of a distant star is determined to be 59,000 K. How much more power does it emit than the sun does?
10,000 times more
• The main advantage to using the Hubble Space Telescope it that focusing problems due to atmospheric disturbances are eliminated
• The term "seeing" is used to describe how bright an object the human eye can tolerate without damage to the retina.
• A CCD is used to electronically record images from a telescope
• Radio telescopes are large in part to improve their angular resolution, which is poor because of the long wavelengths at which they
• Infrared astronomy can only be done from space
• X-ray and gamma-ray telescopes employ the same basic design as optical instruments
• Because gamma rays have very short wavelengths, gamma-ray telescopes can achieve extremely high angular resolution
• The main reason that most professional research telescopes are reflectors is that
mirrors produce sharper images than lenses do since there is no chromatic aberration.their images are inverted
• If telescope mirrors were made in odd sizes, the one with the most light-gathering power (even if the mirror is not circular) would be
a rectangle with two 1-m sides and two 2-m sides.
The PRIMARY reason professional observatories are built on the highest mountain tops is to
Reduce atmospheric blurring
When multiple radio telescopes are used for interferometry, resolving power (angular resolution) is most improved by increasing
the distance between telescopes
The Spitzer Space Telescope is stationed far from Earth because
This infrared telescope actually does not orbit the Earth, but follows our planet around the Sun, reducing the heat interference from Earth
The best way to study young stars hidden behind interstellar dust clouds would be to use
(Resolution) is sharpest when the ratio of wavelength to telescope size (i.e. lambda/D)
the best frequency range in which to study the hot (million-kelvin) gas found among the galaxies in the Virgo cluster would be
An FSU student is observing the phases of Venus with his 8 inch reflector telescope, and a UF student is doing the same with a 16 inch reflector telescope. How much more light gathering power does the UF telescope have?
4 times more
Again, an FSU student is observing the phases of Venus with his 8 inch reflector telescope, and a UF student is doing the same with a 16 inch reflector telescope. How much "more" resolving power (i.e. angular resolution) does the UF telescope have?
Twice as much.
Once again: The FSU student and the UF student decide to do some radio astronomy and look at an intergalactic molecular cloud with their 30 meter dishes. They are looking at 60 micrometer light. What is the resolving power of each of these telescopes.
The FSU student and the UF student decide to do some radio astronomy and look at an intergalactic molecular cloud with their 30 meter dishes. They are looking at 60 micrometer light. The decide that the resolution is not sufficient to see the details of the cloud. What can they do?
They each stay at home, but get a fast internet link, and link the outputs of the two radio telescopes together with a computer.
If you wanted to detect gamma ray radiation from a very violent stellar event, what would you do?
Write a proposal to NASA to get observation time on the Compton Telescope
All the terrestrial planets lie inside the asteroid belt
Pluto's orbit has the lowest inclination to the ecliptic of any planet.
One characteristic of the Terrestrial planets is their extensive moon systems.
All the planets' orbits are evenly spaced
Earth is nearly twice as large as Venus.
All the planets revolve around the Sun counter clockwise, except for Venus and Uranus.
All the planets orbit the Sun in exactly the same plane as the Earth
The two smallest planets, Mercury and Pluto, have no moons.(Assume Pluto is a planet!)
All four Jovian planets are thought to have cores larger than Earth.
All Jovian planets have rings around their equators and at least eight moons.
Pluto is more similar to the jovian planet's icy moons than to any of the other planets
Due to their great masses, all four Jovian worlds are much denser than the earth.
A Kuiper Belt object was recently discovered that may be larger than Pluto.
Barringer Crater in Arizona is an example of a meteorite impact
Most astronomers now believe the demise of the dinosaurs 65 million years ago was caused by a large asteroid impacting the Yucatan peninsula area
Meteor showers are the result of collisions between asteroids.Meteor showers are the result of collisions between asteroids.