The main reason that most professional research telescopes are reflectors is that:
large mirrors are easier to build then large lenses
Primary purpose of astronomical Telescope?
to collect a lot of light and bring it to focus
Most important advantage of CCD' over film is?
they record much more light in a given exposure time
Currently supplying high resolution X-ray images from space:
Chandra
Conservation of angular momentum means that a spinning body tends to:
keep spinning
Mass is easiest to measure when:
they have natural satellites whose motions can be precisely measured
Determine mass with Newton's law of motion and gravity:
Moons
Planetary orbits:
are almost circular, with low eccentricities
Objects in the Kuiper Belt:
lie beyond the orbit of Neptune, and close to the ecliptic
Where terrestrial planets form?
anywhere between 0.03AU and the frost line
Why do orbits of then planets all lie in the same space?
early solar nebula flattened into a disk
What might have made the original solar nebula begin to contract?
the shock-wave from a nearby exploding star
Future scientists determine which is better (core-accretion model vs gravitational inversion theory) by:
measuring the mass of rocky material in the Jovian Planets' core
How is the existence of Earth's unique atmosphere explained?
The oxygen in earth's atmosphere is a result of early life on Earth
Which part of Sun's radiation are responsible for heating Earth's Surface?
The visible and infrared
What is the hole in the ozone layer thought to be caused by?
CFC's
On a cloudless day, what happens to most of the visible light headed toward Earth?
It reaches Earth's surface, where some is reflected and some is absorbed
If seismometers registered P- and S-waves everywhere on the moon, they would suggest that the Moon had:
No molten core
Earth's average density
It is higher than the density of surface rocks
What natural phenomenon provides information on the structure of Earth's core?
Earthquakes
What has been the primary mechanism for the creation of the large-scale features of Earth's continents and crust?
Drift of crustal plates due to convection in the asthenosphere
When solar winds are displaced poleward by our magnetic field, we get:
intense auroral displays
Earth's Magnetic Field:
prevents charged particles in the solar wind from reaching the surface
What is the best description of the Earth's rotation over its entire history?
It has slowed down very gradually at about 0.0015 seconds per century
At what phase are the tides least noticeable?
First and Third Quarter
Lunar Mane are formed:
almost entirely on Earth side, where the crust was thinner
The Lunar Highlands are:
more rugged, heavily cratered, and older than the Lunar Mare
True about Lunar Highlands?
They are the oldest part of the lunar surface
The lunar mare are radioactively dated at:
3.9-3.2 billion years old, forming after most of the bombardment was over
Why are there more craters in Lunar Highland rather than the maria?
The highlands are older than the maria