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