astro quiz 12

In 2013, a small stony asteroid collided with the Earth above the Russian city of Chelyabinsk. What was the result? A large earthquake was felt all over Europe and Asia The Earth's orbit around the Sun changed in a measurable way It burned up so high in the atmosphere, absolutely nothing could be felt or seen on the ground A fireball briefly brighter than the Sun could be seen in the sky It broke apart and large pieces of rock fell from the sky, killing thousands of innocent people

A fireball briefly brighter than the Sun could be seen in the sky

According to our textbook, what is the best way to defend ourselves against an asteroid which is on course to collide with the Earth in 7 years? There is no possible protection for us; if an asteroid is headed our way, we are all doomed Asteroids are all rubble piles, so the only thing that would protect us would be a huge thermos-nuclear explosion that vaporizes the entire asteroid The only thing we could do would be to move some people to the Moon so they could survive There is no problem, because all asteroids burn up by friction in the Earth's thick atmosphere If we do it early enough, we could explode something on or near the asteroid to deflect it slightly, so that years later it would then miss the Earth

If we do it early enough, we could explode something on or near the asteroid to deflect it slightly, so that years later it would then miss the Earth

Which of the following statements about NEO's (Near Earth Objects) is TRUE? no NEO has passed closer to the Earth than the orbit of the Moon it is unlikely that any NEO's have hit the Earth during our planet's history NEO's can include both asteroids and comets that cross the Earth's orbit we are not able to obtain information about the shape or size of any of the NEO's at present we have identified just about all NEO's with diameters greater than 1 km

NEO's can include both asteroids and comets that cross the Earth's orbit

In 2012, NASA's Spaceguard Survey concluded that astronomers had now identified 90% of the asteroids with diameters greater than 1 km. How could astronomers know that they had reached this goal? NASA is now able to keep track of everything in the solar system out to Pluto with great precision; nothing remains to be discovered in that region The people doing the survey began to find the same objects over again, indicating they were reaching the limits of their survey Asteroids larger than 1 km are so rare and so big, they have always been easy to keep track of Most of the near-Earth objects that big are comets, and they all have big tails which are easy to see This was fake news; in fact, we can't ever know if we have found 90% of the larger near-Earth objects

The people doing the survey began to find the same objects over again, indicating they were reaching the limits of their survey

How can astronomers measure the age of a meteorite that fell from the skies? The age of a meteorite can be found from the angle at which it enters the Earth's atmosphere; so scientists can only get the ages of meteorites they observe falling They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products There is no way to measure the age of any meteorites Meteorites all contain metals and the metal conducts electricity better and better as it ages Just like for planets, we measure the age by counting the number of craters on the meteorite

They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products

The typical meteor is visible only from above the Earth's atmosphere made of evaporated ices about the size of a small one-family house the result of magnetic activity in the upper atmosphere of the Earth a small solid particle, no bigger than a pea

a small solid particle, no bigger than a pea

When a chunk of cosmic material the size of a golf ball or a baseball hits the Earth's atmosphere it makes a meteor shower trail so faint, there is no chance of our seeing it on the ground fireball radiant meteorite which breaks into pieces when hitting the ground

fireball

Chunks of solid material that survive passing through the Earth's atmosphere and are found on the Earth's surface are called comets meteorites meteors meteor showers asteroids

meteorites

When the solar system was forming, the building blocks from which the protoplanets gathered together were the: extremely hot clouds of gas torn out of the Sun, which was already shining brilliantly giant accretion grains about the size of Mars planetesimals (a few km to tens of km wide) gold, iron, and nickel atoms pure water ice crystals, about the size of a snowflake

planetesimals (a few km to tens of km wide)

How do astronomers know that the age of the solar system is about 4.5 billion years old? they estimate that age from the number of comets that are still located in the Kuiper Belt they estimate the date from the number of impact craters on the Earth radioactive dating of all the rocks on Earth shows that age they have the warranty book for each planet, and it tells you when the unit was manufactured radioactive dating of the primitive meteorites indicates they have that age (since they are left-over building blocks of the solar system)

radioactive dating of the primitive meteorites indicates they have that age (since they are left-over building blocks of the solar system)

Which of the following is not a characteristic that worlds in our solar system have in common: that most of the planets spin in the same direction that they revolve that the planets' orbits lie in roughly the same plane that the planets all revolve around the Sun in the same direction that many of the larger moons go around their planets in the same direction as the planet's rotation that all the planets have solid surfaces on which we can see impact craters

that all the planets have solid surfaces on which we can see impact craters

One region on Earth that has become a rich source of new meteorites in recent decades (including the meteorite from Mars that got famous because some scientists claimed they had found evidence for the building blocks of life on Mars) is: the Great Salt Lake the Yucatan peninsula of Mexico the Antarctic Australia Columbus, Georgia

the Antarctic

Which of the following is NOT evidence that objects from space collide with the Earth? the devastation that happened in 1908 near the Tunguska river in Siberia Meteor Crater in Arizona the crater at the top of the Mount St. Helens volcano the Chicxulub crater buried near Mexico you can't fool me; all the above are the results of cosmic impact

the crater at the top of the Mount St. Helens volcano

In 1980, scientists suggested that the great mass extinction of 65 million years ago (which ended the reign of dinosaurs) may have been caused by a large impact from space. What discovery gives a big boost to this idea? the discovery of a crater (about a mile across) near Flagstaff, Arizona the discovery of enormous trenches on the ocean floor the discovery of a buried crater (about 200 km across) near Chicxulub, Mexico the discovery of some possible traces of life in a meteorite from Mars the discovery of volcanoes on a moon of Jupiter

the discovery of a buried crater (about 200 km across) near Chicxulub, Mexico

The ages of stony meteorites have been measured to be roughly equal to: the time that has passed since the death of Julius Ceasar the time since the last Ice Age on Earth the oldest ages we have measured for any bodies in the solar system the time since the great impact that killed the dinosaurs you can't fool me, we have no way of measuring the ages of stony meteorites

the oldest ages we have measured for any bodies in the solar system

Which of the following pieces of observational evidence does our modern "solar nebula" theory of the formation of the solar system NOT explain directly? the existence of comets in the outer solar system made mainly of frozen gases the ages of the oldest rocks on Earth, the Moon, and meteorites the plane of the orbit of Pluto the difference in the composition of the terrestrial and jovian planets the fact that all the planets revolve around the equator of the Sun in the same direction

the plane of the orbit of Pluto

Which of these did the June 1908 impact event in Siberia and the 2013 event in the Russian city of Chelyabinsk have in common? they both exploded high in the atmosphere and produced a shock wave that reached the ground they both killed a lot of innocent people they both produced a large crater, which has become a tourist attraction they both went completely unnoticed by people (and we only know about them from instruments in space) you can't fool me, those events had nothing in common

they both exploded high in the atmosphere and produced a shock wave that reached the ground

A key difference between the protoplanets that formed in the outer solar system and those that formed in the inner solar system was that those in the outer solar system did not have enough planetesimals nearby those in the outer solar system were in a place where ice, not just rock, condensed and thus could grow larger those in the outer solar system included far more metal and rock, and thus the outer planets could be denser you can't fool me, there were no differences between the inner and outer protoplanets; only the planets that finally formed are different. those in the inner solar system were much larger than those in the outer solar system

those in the outer solar system were in a place where ice, not just rock, condensed and thus could grow larger

Among solid worlds, which type of world is most likely to have significant geological activity? those that are farthest from the Sun those that are the smallest (and thus easiest to heat) those that have strong magnetic fields those that have a moon (satellite) those that are the largest (and retain heat the best)

those that are the largest (and retain heat the best)

A student in your class whom you kind-of like asks you come to watch a meteor shower. What exactly are you being invited to? a once-in-a-lifetime experience at the end of which you will be completely covered with dust particles from space watching the left-over dirt from a comet burn up by friction as the pieces hit the Earth's atmosphere something quite dangerous where you are likely to be hit when many larger rocks fall from above something your mom would not approve of, involving streams of dirty water the closest approach of an active bright comet to the Earth

watching the left-over dirt from a comet burn up by friction as the pieces hit the Earth's atmosphere