Astronomy Exam 2 - Dwarf planets and minor bodies

Sunlight heats my ice, turning it from solid to gas

comet

I orbit between Mars and Jupiter and am mainly made of rock

asteroid

My orbit is huge, very eccentric, and can be inclined almost any direction to the plane of the solar system

comet

I orbit right alongside Ceres --- we "rock out" our orbit together because I'm made of rock!

asteroid

I spend most of my time in the outer edges of the solar system, although I do swing close to the Sun very quickly for a tiny part of my orbit

comet

Earth runs into dust and rocks from my tail and experiences meteor showers

comet

Bright streak of light in the sky as air is heated by debris falling from space

meteor

Piece of rock or metal that survives entry into the Earth's atmosphere and lands on the ground

meteorite

Rock (usually) leftover from a comet tail that is in space but about to enter the Earth's atmosphere

meteoroid

Rock or metal objects orbiting the Sun with semi-major axes between Mars' and Jupiter's

asteroid

Icy and dusty objects orbiting the Sun with semi-major axes ranging from just larger than Neptune's to the edge of our solar system

comet

How often does the Earth enter the asteroid belt?

never

Extra credit: In Star Wars the ship had to dodge around closely-packed asteroids in an asteroid belt (like this). Is this realistic?

no, asteroids are small compared to their orbit sizes, so they are very widely-spaced with large distances between them

With a semi-major axis of 2.8AU, where does dwarf planet Ceres live?

asteroid belt

Which is true about minor body orbits?

asteroids have smaller orbits but comets get closer to the Sun

There are many small bodies (yellow) that orbit the Sun roughly in a plane. The images below show it from the side and from above. Jupiter and its orbit are shown in blue, therefore these are diagrams of the

asteroid belt

There are many small bodies (yellow) that orbit the Sun roughly in a plane. The images below show it from the side and from above. Neptune and its orbit are shown in blue, therefore these are diagrams of the

Kuiper belt

There are many small bodies (yellow) that orbit the Sun roughly in a sphere. The images below show it from the side and from above. Neptune and its orbit are shown in blue, therefore these are diagrams of the

Oort cloud

With a semi-major axis of 39AU, where does dwarf planet Pluto live?

Kuiper belt

Tautatis is a small, irregularly shaped object in the asteroid belt that orbits the Sun. This is an animation showing Tautatis rotating. What would we classify it as?

minor body

Amalthea is a small, irregularly-shaped object that orbits Jupiter. This animation shows Amalthea rotating. What would we classify it as?

moon/satellite

How would we get Saturn's moon Titan to be reclassified as a dwarf planet?

make it orbit the Sun in a debris region like the asteroid belt

How would we get Mercury to be reclassified as a minor body?

remove mass so it's irregularly-shaped

Halley's comet has a semi-major axis in the Kuiper belt. Why isn't it considered a dwarf planet like Pluto and the others?

it is irregularly-shaped

How do comet tails behave as the comet orbits the Sun?

the comet only has tails when it is close to the Sun, and the dust tail stays in the orbit and the ion tail always points away from the Sun

Which of these are dwarf planets in our solar system? Select all that apply.

Haumea, MakeMake, Ceres, Eris,Pluto

The astronomer who discovered the dwarf planet Eris suggests there might be another object far beyond the Kupier belt. If this Planet X exists, it would be about 10 times the mass of Earth and 2-3 times the size of Earth, putting it in the ice giant category, and have an orbit with a semi-major axis of 700 AU. You can read more about this object on NASA's page. If this object exists, what would we classify it as?

planet

The video embedded in this article shows asteroids of various sizes as compared to the size of New York City. The video starts with some very tiny asteroids and ends with the largest object in the asteroid belt, Ceres. Why are the larger asteroids more spherical in shape?

more mass means a stronger gravity, which pulls in any pieces that are sticking out too much

Extra credit: Please watch Vox's "NASA's plan to save Earth from a giant asteroid" We would need advanced warning to change the motion of an asteroid headed toward Earth. What is the minimum time we would need with our current technology?

more than 10 years