HW#7

Meteoric material dates the formation of the solar system at about_____ billion years

4.6

What is the approximate age of the soar system according to the best available scientific evidence

4.6 Billion

What is the asteroid belt?

A large group of asteroids with orbits located between Mars and Jupiter.

Which of the following statements about comets is incorrect?

At its largest, the coma is roughly 10 times bigger than the nucleus of the comet itself.

The dwarf planet Eris was discovered in 2005, orbiting the Sun at an average distance about twice that of Pluto. In which of the following ways do Pluto and Eris differ from the terrestrial and jovian planets in our solar system?

Both Pluto and Eris are smaller than any of the terrestrial planets. Both Pluto and Eris travel in more elliptical orbits than any of the terrestrial or jovian planets. Both Pluto and Eris are less massive than any of the terrestrial or jovian planets.

What is the source of the material of a meteor shower?

Coments

Listed following are some distinguishing characteristics of comets, meteors, and asteroids. Match these to the appropriate category of objects.

Comets - form a coma when near the Sun - most are located either in kuiper belt or oort cloud - visible in the sky as a fuzzy patch of light that rises and sets with the stars Meteors - visible in the sky as a bright streak of light for only a few seconds -dust particles entering earth's atmosphere at high speed Asteroids - compositions similar to that of the terrestrial planets - typically orbit the sun at approximately 3 au

Which of the following objects are composed of material mostly unchanged since the formation of the solar system?

Comets and asteroids

All the planet's orbits are evenly spaced.

False

All the planets revolve around the Sun in the same direction, except for Venus and Uranus.

False

Astronomers have not yet been able to detect planets outside our solar system.

False

Comets are not actually members of the solar system, but have been captured by the Sun.

False

Due to their great masses, all four jovian worlds are much denser than the Earth.

False

Earth is nearly twice as large as Venus.

False

One characteristic of the terrestrial planets is their extensive moon system

False

The Oort Cloud lies closer to the Sun than the Kuiper Belt.

False

The smallest planet, Mercury, and the dwarf planet, Pluto, have no moons.

False

What is the process of accretion?

Growth of an object by the accumulation of matter

Which of the following are the jovian planets?

Jupiter, Saturn, Uranus, and Neptune only

Which planet by itself contains the majority of mass of all the planets

Jupitor

Which of the following is NOT a characteristic of terrestrial planets?

Lower density than jovian planets

Rank the objects from left to right based on their average distance from the Sun, from farthest to closest.

Pluto Saturn Jupiter Mars Earth Mercury

Rank these objects from left to right based on their mass, from highest to lowest.

Sun Jupiter Earth Mars Mercury Pluto

The images below show six objects in our solar system. Rank these objects by size (average equatorial radius), from largest to smallest. (Not to scale.)

Sun Jupiter Earth Mars Mercury Pluto

Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets?

Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets.

What is true about solar system densities?

The denser planets lie closer to the Sun.

The early solar nebula flattened into a disk

The early solar nebula flattened into a disk.

Which of the following is NOT a way in which the terrestrial and jovian planets differ?

The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets.

Which of the following is NOT a property of long-period comets that suggests that they originate from the Oort cloud?

They orbit around the Sun in a counterclockwise direction, when viewed from above the ecliptic plane.

All jovian planets have rings around their equators and at least eight moons.

True

All the terrestrial planets lie inside the asteroid belt

True

As a rotating gas cloud contracts, it spins faster.

True

Barringer Crater in Arizona is an example of a meteorite impact.

True

Cometary dust tails lag behind the bluish ion tails as the comet rounds the Sun.

True

Most astronomers now believe the demise of the dinosaurs 65 million years ago was caused by a large asteroid impacting the Yucatan peninsula area.

True

In addition to revolving around the Sun counter clockwise, most planets also rotate on their axis counter clockwise.

Truw

Which planet is approximately halfway between Pluto's orbit and the Sun?

Uranus, the seventh planet from the Sun

Extrasolar planets have been detected using all of the methods listed here.

Which of the following methods have astronomers used to detect extrasolar planets?

A meteorite is

a chunk of space debris that has struck the ground.

A meteor is

a streak of light in the atmosphere.

The Kuiper Belt is found where in the solar system?

beyond the orbit of Neptune

If a comet's ion tail is pointing perpendicular to its direction of travel, the comet is

close to or at perihelion.

Which of the following have an icy composition?

coments

The ingredients of a typical comet's nucleus are most likely ________.

dust and rocky particles trapped in methane, ammonia, and water ice

Density is defined as

mass per unit volume.

Compared to terrestrial planets, jovian planets are __________.

more massive and lower in average density

The number of conirmed exoplanets is`

more than 500

Which of the following does not fall into the category of interplanetary debris?

rings around the jovian planets.

The Trojan asteroids are found

sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun.

As the solar nebula contracts, it

spins faster due to conservation of angular momentum

Long-period comets are believed to originally come from

the Oort cloud.

Relative to the comet, the direction of the ion tail tells us

the direction of the Sun.

In some cases, we have seen extrasolar planets pass in front of their stars.

true

The total mass of all the planets is much less than the mass of the Sun.

true

Meteor showers are

usually annual events, as the orbits again intersect. caused by the Earth passing near the orbit of an old short-period comet.