8 - Distant Worlds

Tunguska Meteor

collided with Siberia on June 30th 1908, seismic vibrations were recorded 600 miles away (exploded before hitting the ground), diameter of about 50-60 m

.we don't know how to listen

One solution to the Firmi Paradox suggests that aliens are broadcasting, but...

Dwarf planets

Pluto, Eres, Quaoar, Ceres Sedna & other large Kuiper Belt Objects are referred to as...

1st Stage in history of solar system

collapse & rotation of a large, diffuse cloud

Gas giants (Jovian planets)

giant planets which range from 4 to 10 times larger than the diameter of Earth. Jupiter, Saturn Uranus & Neptune have huge gaseous atmospheres; composed mostly of Hydrogen & Helium

Extrasolar planets

planets orbiting other stars, give clues to how solar systems form, how unique the Earth may be, & whether there is likely to be life elsewhere in the universe

Exoplanets

planets outside of our solar system

The Zoo Hypothesis

super-intelligent alien life may answer to a Prime Directive of don't interfere

Firmi Paradox

the assumption that we should have detected intelligent life in the universe by now

Kuiper Belt Objects (KBO)

moon-sized objects, discovered near Pluto's orbit, which are cold & geologically dead

D. gas

Almost the entirety of Jupiter's size is made up of ... A. solid B. liquid C. water D. gas

Drake Equation

a simple equation to estimate the number of intelligent civilizations in our galaxy

Collapse of the Solar Nebula

a theory that details the beginning of our solar system

Comets

"Dirty Snowballs" Tail always extends away from the Sun Most elliptical objects in solar system

B. killer asteroids

"More money is spent on making movies about ____________ than on actually finding them." A. exoplanets B. killer asteroids C. aliens D. comets

C. is cold .... has a ton of gravity

A planet will keep a large atmosphere if it _________ or __________. A. is warm .... has a ton of gravity B. is warm .... has a small amount of gravity C. is cold .... has a ton of gravity D. is cold .... has a small amount of gravity

Eris

Discovered in 2005 by Mike Brown, was a dwarf planet that appeared larger than Pluto

C. 40 miles

During the Tunguska Event, people were thrown 20 feet through the air, even though they were ________ away from the explosion. A. 5 miles B. 2 miles C. 40 miles D. 500 feet

12

Early plans to resolve Pluto's planetary debate increased the number of planets to...

Saturn

Similar in size to Jupiter, primarily tan colored, has a unique prominent ring system

center, edge

The Nebula stayed hotter near the... and cooled more rapidly on the...

C. Transit Method

The _________ for discovering exoplanets looks for tiny dips in light as a planet passes in front of its star. A. Doppler Effect B. Nebular Theory C. Transit Method D. Doppler Method

D. Eris

The discovery of _________ prompted astronomers to reconsider whether Pluto should really be called a planet. A. the Oort Cloud B. Pluto's moon C. the asteroid Ida D. Eris

B. 2000 K

The gas in the solar nebula began at a temperature of about .... A. 300 K B. 2000 K C. 3 K D. 1000 K

D. It has cleared the neighborhood around its orbit

Which of the following parts of the formal definition of a planet does Pluto fail to meet? A. It is a celestial body B. It is found in a roughly round shape C. It is in orbit around the Sun D. It has cleared the neighborhood around its orbit

Simulated Universe

a hypothesis in answer to the Firmi Paradox that argues that at least one of the following must be true1. Humans are likely to go extinct before they are able to create entirely simulated realities. 2. A post-human civilization with the ability to run such a simulation would likely not run many simulations. 3. We are currently living in a computer simulation.

Kardashev scale

a hypothetical classification system for an alien civilization based on it's energy consumption

Transit Method

a method for detecting exoplanets where distant stars are monitored for dips in light as a planet passes in front of it

Titan

a moon of Saturn that is covered by a thick orange haze; it has mountains, valleys, and is the only (known) world in our solar system that has liquid on it's surface in the form of Methane

Neptune

about 4x the diameter of earth, primarily blue colored

Uranus

about 4x the diameter of earth, primarily blue colored

Io

an explosive moon of Jupiter, gets hot because of the contortion formed by the gravitational pull of other Jupiter's other moons; this energy fuels massive volcanoes

Carbon dioxide & other materials

condenses into frozen solids in the cold outer Solar System

Condensation Sequence

different mineral compounds condense at different temperatures

Helium

element that is inert & doesn't form chemical compounds

Asteroids

enormous rocks in space that could hit the earth, are the size of large cities or even whole countries

Gaseous or icy material

is a major building block of the outer worlds, while rocky material is only a secondary component (the ratio of rock & ice is roughly equal)

Jupiter

largest planet in our solar system; contains 71% of the total mass of all the planets (about 10 times earth's diameter); primarily tan colored

SETI

search for extraterrestrial intelligence

2nd Stage in history of solar system

slow & steady formation of planets from microscopic particles in the solar nebula; as the solar nebula cooled, molecules condensed into droplets, then solidified into tiny solid particles

Doppler Method

the primary tool for discovering exoplanets from ground based telescopes

Planetesimals

the small, solid bodies that formed in the primordial solar system (include comets & asteroids)

Kardashev Type 2

this civilization harnesses the energy output of a star, & generates about 10 billion times the energy output of the previous Type of civilization

Kardashev Type 1

this civilization harnesses the energy output of an entire planet

Rare Earth Hypothesis

this hypothesis disputes the first & second assumptions of the Fermi paradox (Earth is a typical planet revolving around a typical star) and suggests that there is something special or rare about Earth that allows complex life to form & thrive

Hydrogen

universe's most common element

Saturn's rings

visible rings orbiting a planet, they are not solid but made up of particles of rock & ice

Red Shift

when something that is giving off light moves away from the observer & the wavelengths lengthen

Blue Shift

when something that is giving off light moves towards the observer & the wavelengths shorten

Youngness Paradox

young pocket universes vastly outnumber older universes & there is a minimum time required for intelligent life to develop; it is unlikely that there is an alien civilization in our own universe even one second more advanced than ours

A. few centuries

An explosion the size of the Tunguska Event is likely to happen every.... A. few centuries B. 1,000 years C. 10,000 years D. 100,000 years

B. metals

As the solar nebula cooled, which compounds were the first to condense from a gas to a solid? A. water B. metals C. ices D. rocks

B. 300 - 500

How many asteroids (that we know of) are on a potential collision course with Earth? A. 25 - 50 B. 300 - 500 C. 10,000+ D. 0 - 5

D. blue-shifted

If a star is traveling toward you, its observed spectrum will be .... A. red-shifted B. fainter C. brighter D. blue-shifted

1379.46875

If the peak wavelength of a star at rest is 1375 nm, then what peak wavelength is observed when the star is traveling 975,000 m/s away from the Earth.

609.875

If the peak wavelength of a star at rest is 615 nm, then what peak wavelength is observed when the star is traveling 2,500,000 m/s toward the Earth.

D. biosignatures

If we could capture the spectrum of an exoplanet, we may find evidence for life on that planet in the form of .... A. water vapor B. ozone C. earthshine D. biosignatures

Gravitational dominance

The new criteria for defining a planet that Pluto failed to achieve (determining it a Dwarf planet) was...

Velocity

The size of the doppler shift depends only on the relative... between the light source & the observer

Kardashev Type 3

This civilization harnesses the energy output of a galaxy, or about 10 billion times the energy output of the previous civilization

Kuiper Belt

a population of small, icy bodies beyond the orbit of Neptune

Asteroid belt

a region of the solar system just beyond the orbit of Mars where hundreds of thousands of rocks orbit the sun, occasionally colliding with one another

Doppler Effect

the change in wavelength due to the relative motion between the source & the observer along the line of sight (when something moves towards or away from you, the wavelength changes)

Great Filter

the idea that the development of a civilization that can colonize a galaxy is a unique, maybe once in a universe event because of the many exceptional barriers to life along the way 1. Star system 2. RNA 3. Simple single-cell life 4. Complex single-cell life 5. Sexual reproduction 6. Multi-cell life 7. Tool-using animals w/ big brains 8. Where we are now 9. Colonization explosion