Endtime Quiz | Astronomy

Quiz Answer Key and Fun Facts

1. Outer space is, in some ways, similar to subatomic space. It's largely empty with vast distances between objects. But sometimes all that distance isn't enough to ensure that there won't be some sort of collision. On December 9, 1994, a near-Earth object (NEO) called 1994 XM1 passed within 105,000 kilometres of Earth. What was the approximate mass of this object?

Answer: The size of a large house

The object was only discovered 14 hours before it would have impacted Earth if it hadn't barely missed. Not much time to prepare. One of that size wouldn't have caused massive destruction, but could have caused a lot of grief if it had come down in a populous area.

2. Concentrated scientific effort has allowed us to predict how many NEOs (near Earth objects) probably exist. An NEO is defined as an asteroid or comet that, at some point, will travel close enough to Earth to pose a small potential impact risk. As of 2003, approximately half of all the large (greater than 1 kilometre in diameter) predicted NEOs have been visually identified and tracked. The total number of large NEOs that are predicted to exist is:

Answer: About 1,000

The greatest risk to the planet comes from the NEOs that we don't know about yet. Of the ones that have been discovered, none are imminent threats, but at any time one of the ones we haven't found yet could sail into the atmosphere and wreak havoc. It's not very likely of course; but the possibility does exist.

3. How many people worldwide are involved in the nightly search for NEOs?

Answer: Less than 100

It can be a bit of a sobering thought that less than a hundred people are involved in the quest to predict the only natural disaster that we have any control over. A hurricane or an earthquake or a tidal wave may strike your home town, and all you can do is hope to run away.

But if we were to discover an NEO that was on an impact trajectory with Earth, as a species we have the technological capability, given a long enough warning period, to deflect or destroy the dangerous object. It seems to be a characteristic of the human race that we want to "live in the moment", but perhaps this is one case where putting a little more effort toward "looking to the future" might be worth it.

4. Most people have heard of the Tunguska Event in 1908; a medium-sized NEO (near Earth object-probably about 50 metres in diameter) entered the Earth's atmosphere and detonated with massive force, releasing the power of many nuclear bombs and causing destruction over hundreds of square miles. What was unusual about this occurrence?

Answer: The meteorite exploded above the Earth's surface

Scientists were unable to reach the site of the explosion for nearly 20 years after the event took place, due to the unstable political climate in the region. When a team finally arrived they found that trees near ground-zero of the impact were still standing, although charred, whereas trees further out were flattened. For a long time this caused speculation that it wasn't an asteroid impact at all, but rather something else, which was the subject of much debate. Eventually fragments of stone from an asteroid were discovered embedded in several of the trees still standing which convinced scientists that the explosion was really caused by a meteorite - one that probably exploded about four miles above the Earth's surface.

5. What is the approximate size an asteroid would have to be, in order for its impact to initiate a short-duration global winter?

Answer: 1-2 kilometres in diameter

Asteroids of this size, on average, have impacted the earth once or twice per million years. A "short-duration" global winter might last for a year or two, causing loss of crops and worldwide starvation, but not the mass extinction of the species.

6. The first NEO (near Earth object) was discovered in 1898 and christened "Eros". In addition to being one of the largest NEOs, it has another distinguishing characteristic - it's shaped somewhat like a:

Answer: peanut

It's also been described as a potato, and is one of only a few known NEOs that are larger than 10 kilometres in diameter. It's passed relatively close to Earth three times in the last hundred or so years, but never within a really dangerous distance.

7. What is the acronym for the most successful NEO (near Earth object)discovery project?

Answer: LINEAR

LINEAR stands for Lincoln Near Earth Asteroid Research and is located in New Mexico; it's a joint U.S. Air Force and NASA funded program. In 1999 and 2000, LINEAR discovered more NEOs than all other search programs combined. LONEOS stands for Lowell Observatory Near Earth Asteroid Search and is also a highly successful program which is based in Flagstaff, Arizona. NEAT stands for Near-Earth Asteroid Tracking and is located in Hawaii. Ceres is the name of the largest asteroid in the solar system; it's not anywhere near Earth however.

8. What is the approximate probability of a given person being killed by a meteorite?

Answer: 1 in 20,000

If this statistic sounds incredibly high given that you've probably never heard of anyone who was killed by a meteorite, it's because the data is skewed. Every so often an impact large enough to wipe out just about all life on Earth occurs, and in between times, pretty much no one is killed by a meteorite. So while you have a 1 in 20,000 chance of being killed in this manner, the statistic is not much different for the entire population of Earth combined. If an asteroid large enough to kill people hits, it will probably kill a lot more than a few; but there's a 19,999 in 20,000 chance that it won't happen in your lifetime.

Hence the statistic. If I had asked what the probability was of any given person being individually STRUCK by a meteorite, the answer would be astronomically higher.

9. It's impossible to predict with 100% accuracy when impacts of different magnitudes are going to take place. But we can determine approximate time-frames given that we know the frequency with which such events have occurred in the past. We can expect an impact approximately as powerful as a single nuclear detonation sometime in the next:

Answer: Few centuries

The Tunguska blast described in question 5 was around the proper order of magnitude to qualify as one of these impacts; as objects in the 50-metre diameter range have historically impacted every few centuries, we can expect another relatively soon.

10. An impact on the scale of that which ended the dinosaur era could end the human era as well, if we don't spot it coming in enough time to prevent its occurrence. How much time would we need in advance to be certain of putting up our best possible defense?

Answer: A minimum of ten years

Most experts believe that given ten years' warning, sufficient international cooperation and funding could be gathered to build and/or transport and assemble the necessary ships and weapons to deflect any potentially disastrous NEO. If the warning period was significantly less than that, all we could hope to do would be to predict the landing site and evacuate the nearest people; and even this would be a somewhat useless gesture if the impact was going to be extremely large.

Some astrophysicists believe it could actually take several decades or even up to a hundred years to properly prepare, if the asteroid or comet in question was found to be of enormous size. Everyone involved in the field knows that more money and more effort are needed to make certain our planet remains safe, not only for ourselves, but for the generations to come.

Source: Author arcturiusx

This quiz was reviewed by FunTrivia editor crisw before going online.
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Endtime Trivia Quiz

Many times in the past, life on Earth has been severely affected by impacts of asteroids. It can, and it will, happen again. The only question is when.

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