x24,x03,BottomLeft,x15,x12
our networks
tlcanimal planetscience channelmilitary channeldiscovery health channel
discovery storediscovery adventures
 

Cosmic Collisions

Mother Nature surely likes to throw her weight around.

 

The resulting collisions can be deadly, as any fan of the dinosaurs can tell you, but they do have their silver linings.

 

If you think your cosmic collisions knowledge is smashing, put it to the test with this quiz!

 

by Irene Klotz

image

The entourage circling Saturn includes a large and diverse collection of moons. One was nearly bashed to bits by a meteor or asteroid impact.

 

The crater left behind is about 88 miles wide -- nearly one-third of the diameter of the moon itself! A crater with those proportions on Earth would stretch from Los Angeles to New York.

 

The lucky survivor is:

Titan

Enceladus

Mimas

Tethys

panelImageAltText Good work. You chose: Oops! You chose:
The seventh of Saturn's 34 named moons, Mimas (pronounced "MY mas") took a direct hit sometime in its distant past, leaving behind the largest crater in the solar system -- relative to the size of its parent body, that is.

In 1984, a team of meteorite hunters in Antarctica found an odd potato-shaped rock weighing nearly 5 pounds. It was partly covered with black glass -- a telltale sign that it burned through Earth's atmosphere before crashing some 13,000 years ago.

 

When scientists analyzed the rock, traces of gas in it matched Mars' atmosphere and -- for the first time -- what appeared to be the fossilized remains of bacteria.

 

The object, known as ALH 84001 or the Allan Hills meteorite, was launched off Mars by:

A volcano

A meteorite impact

the Mars Sample Return Mission

An angry Martian

panelImageAltText Great job! You chose: D'oh! You chose:
ALH 84001 had to be moving about 11,000 mph to escape Mars' gravitational pull. The only known natural process to get rocks moving so fast is a meteorite impact. (If you picked C, the Mars Sample Return Mission is only on the wish list at this point.)

The secret to what killed off the dinosaurs 65 million years ago is thought to lie beneath Mexico's Yucatan Peninsula.

 

It's a crater known as Chicxulub, that measures 112 miles in diameter and 3,000 feet deep -- the footprint of an asteroid impact so powerful that it changed Earth's environment.

 

The size of the offending projectile was:

2.5 miles to 3.7 miles in diameter

9.3 miles to 10 miles in diameter

10 miles to 12 miles in diameter

No one really knows

panelImageAltText Best answer. You chose: Yes, but no... You chose:
Estimates for the size of the asteroid that caused the Chicxulub Crater were pretty much set at 9.3 to 12 miles in diameter -- until a team at the University of Hawaii published a study last year. The new research, based on an isotopic analysis of deep- ocean sediment, suggests the killer rock would not have been bigger than 3.7 miles in diameter, which really means that perhaps the best answer is D -- no one knows.

As the Earth was pulling itself together some 4.5 billion years ago, an object about the size of Mars smashed into the planet, throwing up a cloud of material that would over time come together to form the moon.

 

That's the current theory of the moon's formation. A previous, seriously considered option was:

Fission theory -- early Earth spun rapidly enought to shed material and form the moon

Capture theory -- the moon formed elsewhere in the solar system and Earth's gravity nabbed it

Double planet theory -- the Earth and moon grew together out of the same stuff.

All of the above

panelImageAltText Fantastic! You chose: Only partly correct... You chose:
All of the above were options at one time, though after the Apollo moon missions returned the first samples from the lunar surface scientists were at a loss to explain why the Earth had iron and the moon didn't. This one fact took the punch out of these early theories, one of which -- the fission theory -- was proposed by Charles Darwin's son.

For the first time in history, scientists recently had a ringside seat to watch a comet crash into a planet. The comet had been discovered the previous year by astronomers Carolyn and Eugene Shoemaker and David Levy.

 

The impact sent plumes of material thousands of miles into space and caused dark scars on the planet.

 

The unlucky target planet was:

Jupiter

Saturn

Venus

Mars

panelImageAltText Correct. You chose: Nope. You chose:
Between July 16 and July 22, 1994, hundreds of observatories around the world kept watch as fragments from comet Shoemaker-Levy 9 plowed into Jupiter. The largest of the 20 known fragments that impacted the planet were about 1.2 miles in diameter.

Closer to home, the most powerful meteorite impact in recent history occurred on June 30, 1908.

 

Scientists estimate that a 220-million-pound space rock entered Earth's atmosphere traveling about 33,500 mph. The entry ignited the atmosphere to temperatures as high as 44,500 degrees Fahrenheit as it fell through the sky.

 

When it was about 5 miles from the ground, heat and pressure burst the rock into pieces and triggered a massive fireball comparable the energy in about 185 Hiroshima bombs

 

The blast, known as the Tunguska explosion, took place over:

Russia

Indonesia

Arizona

China

panelImageAltText Right locale. You chose: You "blew" it! You chose:
The blast over a remote section of Siberia near the Podkamennaya Tunguska River leveled more than 80 million trees over 800 square miles. Scientists estimate a Tunguska-sized asteroid will enter Earth's atmosphere about once every 300 years.

At the end of 2003, seven major solar storms caused highly charged particles to come crashing into Earth's magnetic field, triggering power outages in Sweden, damaging satellites and disturbing airline routes.

 

Solar storms aren't all bad news, however. They are also responsible for:

Rainbows

Rebuilding the ozone layer

Aurora

High-altitude jetstreams

panelImageAltText Hot answer. You chose: Whoops... You chose:
The sun is in a quiet phase of its 11-year cycle, but stick around for a few years. Scientists estimate that by late 2012, solar activity will be at its peak, triggering beautiful auroras over the planet's northern and southern polar regions.

There's a big hole in the ground some 43 miles east of Flagstaff, Ariz., stretching about 4,000 feet in diameter and about 570 feet deep.

 

Known as Barringer Crater or Meteor Crater, it is one of the best-preserved -- and also one of the first -- craters to tied to a meteor impact.

 

Scientists think the force of the blast that carved out the crater to be:

150 times more powerful than the Hiroshima bomb

At least 2.5 megatons of dynamite

1,500 times more powerful than the Hiroshima bomb

A and B

A and C

panelImageAltText Well done! You chose: Too tricky? You chose:
The impact that left its mark in Arizona tossed up 175 million tons of rock, spreading debris for more than 100 square miles. Scientists estimate its explosive force was equal to 2.5 megatons of dynamite, which is more than 150 times the power of the Hiroshima bomb.

The end of days may have a name: Apophis -- a massive asteroid that could be on a collision course with Earth.

 

Four years ago, NASA scientists announced that there was a 1 in 17 chance Apophis would smash into Earth in 2029. The estimate was later revised to 1 in 45,000, then lowered again last year to 1 in 450. Suffice it to say that keeping watch for potentially killer asteroids is a full-time occupation these days.

 

Engineers, meanwhile, have a few ideas about how to deflect an incoming asteroid, including:

Darken its surface to help the sun's energy "push" it off cours

Blast it with explosives

Send a heavy spacecraft to steer it with gravity

All of the above

None of the above

panelImageAltText Way to go smarty. You chose: Incorrect. You chose:
All of the above -- and a lot more! Other ideas include attaching a rocket engine or solar sail onto the rogue rock to steer it into a different orbit.

Even though space is vast and expanding, gravitational forces put galaxies on collision courses.

 

The resulting crashes can annihilate some structures, but also generate fodder for new stars.

 

Even our own Milky Way galaxy is on a collision course, destined to one day crash into:

Andromeda Galaxy

Triangulum Galaxy

Sombrero Galaxy

A black hole

panelImageAltText Right on course! You chose: Game over! You chose:
The Milky Way and its neighbor galaxy Andromeda are going to get a whole lot closer in the next three billion years or so. The individual stars in the galaxies probably won't collide, but there will be an awful lot of tugging and pushing and pulling. Eventually, though, a new structure will emerge -- a combined elliptical galaxy.

Collision Clueless

Nice try, but you've got a lot of brushing up on Cosmic Collisions to do. Now hit the books!

Space Head

You seem to know your stuff, space head, but there's always room for improvement!

Cosmic Collisions Master

Impressive work! You're truly at the top of your game when it comes to space-based smash-ups.
Print
Email
Advertisement
 
 
 
 

ATTENTION! We recently updated our privacy policy. The changes are effective as of September 10, 2008. To see the new policy, click here.
Questions? See the policy for the contact information.