Astro 120 Final
How far in the future will the Sun run out of fuel?
5 billion years
According to the giant impact model of the formation of the Moon, the collision between what two objects led to the formation of the Moon?
the Earth and a Mars-size body
The Drake Equation allows astronomers to estimate
the number of civilizations within our Galaxy with which we might communicate
In the distant future, we may find another solar system surrounding a star that is just like our Sun in every way. If a planet is found in this system at a distance of 1 A.U. from the star, how long might its orbital period (the planet's year) be?
1 year
According to fossil evidence, how long ago did the first life forms develop on Earth?
3.5 billion years ago
The age of our Earth is approximately
4,500,000,000 years
We receive a radio message from a civilization around a star about 40 lightyears from Earth. If we reply right away, how long will it be between the time THEY sent the message and the time they receive our reply?
80 years
About how long has intelligent life on Earth been detectable to beings on other planets if they use the same sort of tools and techniques that we are using to try to find them?
85 years or so
Why was the discovery of many Jupiter-mass planets in close orbits around their host stars completely unexpected?
Giant planets have to form from volatile material (ices) which only exist far from the star.
Where in the solar nebula would you expect to find planets like the Earth form, and why?
In the inner regions, where heavy elements can condense but ices are vaporized
During fusion reactions in the Sun, the four hydrogen nuclei which are fused together are more massive than the helium nucleus that they make. What happens to the missing mass?
It is converted to energy.
Which new idea has been added into our theory of solar system formation as a direct result of the discoveries of extrasolar planets?
Jovian planets can migrate inward from the orbits in which they are born.
Which pair of constellations would you not expect to see in the same sky at the same time?
Orion and Sagittarius
What problem has precession caused for many of the schools of astrology?
The constellations are no longer lined up with the astrological signs that are named after them; since astrology was set up, the two have slipped one sign apart.
Frank Drake was:
The first person to search for technological civilizations around nearby stars using radio waves.
Why do we strongly suspect that there is an ocean of liquid water beneath the icy surface of Europa?
The surface is broken into many pieces that resemble arctic ice fields and ice floes.
Why do sunspots appear dark?
They are cooler than their surroundings
Some astronomers and geologists have suggested that while simple life (e.g. bacteria) may be common in our universe, planets hosting more advanced life (e.g. elephants) are probably extremely rare. Regarding this idea, which of the following statements is true:
This idea sets at least one of the biological factors in the Drake equation to a very low value.
Which of the following is, to the best of our knowledge, in the habitable zone of its star:
a planet about 1.05 AU from a sun-like star
During this past few years, several news events concerned Astro 120 topics. Which of the following events did we not discuss in lecture?
a small asteroid that exploded in our atmosphere this year
Most of the planets that have been discovered orbiting other solar-type stars have masses that are
between 1 and 3 Earth masses
Astrology and astronomy
differ in that astronomy is a true science, but astrology is a belief system that has failed all rigorous tests
One of the best proofs that our theory of how the solar system formed is correct is that astronomers now observe
disks around other stars which show evidence of gaps where planets may be forming
How will other civilizations probably discover that there is intelligent life on Earth?
early television signals leaking into space
The solar system
formed in much less than one billion years
The most successful technique (so far) to find planets around other stars has been
photometry of stars to look for variations caused by planets blocking some starlight
Which band of the electromagnetic spectrum do astronomers suggest is likely to be the best (cheap, little competition from nature, penetrates atmospheres) for communication between civilizations around different stars?
radio waves
In what part of the sun are pressure and temperature the largest?
the center
What process is responsible for starting the formation of a new star?
the gravitational collapse of part of a cloud of interstellar material
Which of the following is the least important clue about the formation of the planets?
the outer planets have rings
