Astro Quiz 13

What does the Fermi Paradox say? Given the size of the Galaxy, there should be an exact duplicate of the Earth somewhere and we should have found it When Fermi got ill, he always needed two doctors to diagnose him If life on Earth took a miracle to form, then there should be no life anywhere else Given all the time since the Big Bang and all the stars, why has some form of intelligent life in the Galaxy not established a network throughout the Galaxy and visited us? If all the planets in our solar system besides Earth are lifeless, then it must follow that most of the planets around other stars are also lifeless and finding life is hopeless

Given all the time since the Big Bang and all the stars, why has some form of intelligent life in the Galaxy not established a network throughout the Galaxy and visited us?

One reason that some scientists think that there may be life under the ice-crust of Jupiter's moon Europa is that: Life has been found on Earth, at the bottom of the ocean, deriving its energy not from sun-light but from hot mineral-laden vents coming from deeper inside our planet; something similar could happen at the bottom of the ocean on Europa Europa is unusually warm on its surface; in some places the climate resembles Hawaii on Earth. meteorites blasted off Europa have been found on Earth and we detect the building blocks of life inside these meteorites from Europa Life has already been found on Io, Jupiter's inner-most large moon we are receiving intriguing radio messages from Europa that indicate some form of intelligence lives there

Life has been found on Earth, at the bottom of the ocean, deriving its energy not from sun-light but from hot mineral-laden vents coming from deeper inside our planet; something similar could happen at the bottom of the ocean on Europa

Why was the Kepler mission not able to find planets smaller than Mars, even though it was in space (and had no Earth atmosphere to deal with)? Such planets make dips in the light of the star that are too small for Kepler to detect Such planets are only ever detectable using the Doppler shift method Such planets are red in color, and Kepler's cameras could not see red objects Astronomers believe that planets smaller than Mars could not exist Such planets always take longer to orbit their stars than the time the mission lasted

Such planets make dips in the light of the star that are too small for Kepler to detect

Astronomers have concluded that the Sun's activity varies in an 11-year cycle. Which of the following statements about this cycle is TRUE: Every 11 years sunspots completely cover the Sun, making its surface much darker The Sun's activity cycle is directly connected to the number of earthquakes at the continental plate boundaries on Earth The Sun's activity cycle shows absolutely no connection to its magnetic field The number of sunspots gets larger and smaller over the course of 11 years When sunspots are at a minimum, we get the largest number of flares and prominences

The number of sunspots gets larger and smaller over the course of 11 years

Which of the following statements about the Sun's photosphere is NOT TRUE? The photosphere is not a solid layer; if a spaceship (that could withstand the heat) fell through it, it wouldn't feel anything when reaching the photosphere The photosphere is the layer where the Sun becomes opaque (you can't see through it) The photosphere is much less dense than our Earth's atmosphere Through a telescope, the photosphere looks mottled or granulated The photosphere is significantly hotter than all the layers of the Sun beneath it (further inward)

The photosphere is significantly hotter than all the layers of the Sun beneath it (further inward)

Which of the following is, to the best of our knowledge, in the habitable zone of its star: a planet in an orbit the size of the Earth's around a red giant star (much larger and cooler than our Sun) a "hot Jupiter" taking 4 days to orbit a star like our Sun a Jupiter-mass planet taking 15 years to orbit a slightly cooler star than our Sun all of the above a planet about 1.05 AU from a star like our Sun

a planet about 1.05 AU from a star like our Sun

Solar wind particles can be captured by the Earth's magnetosphere. When these particles spiral down along the magnetic field into the atmosphere, they are responsible for: the poor quality of television programming in the world's northern hemisphere the reddish color we see during sunsets aurorae (northern and southern lights) the greenhouse effect tropical storms (regions of rapidly rotating air)

aurorae (northern and southern lights)

Coronal Mass Ejections from the Sun have many serious effects on or near the Earth. Which of the following is NOT one of these effects? disrupting the electronics of satellites causing power surges and power outages in parts of the Earth near the poles causing huge cyclones around the equator of the Earth exposing astronauts and airplane passengers to increased amounts of radiation heating the ionosphere and thus expanding the extent of our planet's atmosphere

causing huge cyclones around the equator of the Earth

The hottest zone in the Sun is the radiative zone core photosphere chromosphere convection zone

core

The most common element in the Sun is water hydrogen helium nitrogen iron

hydrogen

What technique did astronomers use to make the first confirmed discovery of a planet around another star like the Sun? look for a small dip in the light of the star when the planet crosses its disk measure the Doppler shift of the lines in the star's spectrum and look for periodic changes in this shift due to the pull of the planet as it orbits the star search for the presence of metallic and rocky elements in the spectrum of the star block out the light of the star and take a photograph of the fainter planet measure the position of the star on the sky very carefully over many years and search for small wiggles in its position due to the gravitational pull of a planet

measure the Doppler shift of the lines in the star's spectrum and look for periodic changes in this shift due to the pull of the planet as it orbits the star

Astronomers were surprised to find so many Jupiter-mass planets so close to their stars. According to their best theories and models, such "hot Jupiters" must have formed close to their stars, but only billions of years after the star formed must be falling into their stars and will soon be vaporized are absolutely impossible, so they must be mistaken observations must have been captured from a passing star that got very close must have formed further out from the star and must have "migrated inward" early on

must have formed further out from the star and must have "migrated inward" early on

The big surprise about the first planet discovered around another regular star was that it orbited so close to its star it took only 4 days to go around had a spectrum which indicated it was made of elements we never find on Earth had a mass greater than that of most stars was smaller than Mercury or Pluto in our own solar system was inhabited by intelligent creatures which never had to take astronomy quizzes

orbited so close to its star it took only 4 days to go around

Which of the following is a good summary of what most astronomers think about UFO reports in the popular media? it is now clearly established that alien spacecraft have crashed on Earth; we have the bodies of the aliens who flew them here UFO's are now known to come from the planet Mars, the only other planet that we know has life on it UFO's have kidnapped a number of Earth inhabitants, including at least one well-known astronomer; her reports convinced other scientists that UFO's are indeed alien spaceships while no UFO's have landed, we have overheard communications between them with our radio surveys and thus have evidence that there are intelligent creatures aboard them so far there is no scientific evidence that UFO's have anything to do with life outside the Earth

so far there is no scientific evidence that UFO's have anything to do with life outside the Earth

The telescope that allowed astronomers to discover most of the planets found with the transit method was called the Kepler mission the Keck Telescope the Hubble Space Telescope you can't fool me; just about any telescope can show us many, many planet transits the Very Large Array of radio telescopes

the Kepler mission

What mechanisms do astronomers believe is responsible for making the Sun's outer atmosphere so much hotter than its photosphere? astronomers really don't have even a guess about what heats the Sun's outermost layers the ionization of a new element called coronium the Sun's magnetic field interacting with the charged particles that make up the atmosphere stirring by comets, meteors, and other pieces of solid material being pulled in by the Sun's strong gravity light reflected back from the terrestrial planets

the Sun's magnetic field interacting with the charged particles that make up the atmosphere

The Drake Equation allows astronomers to estimate the number of civilizations out among the stars with which we might communicate the age of the universe the location of the Sun within the Milky Way Galaxy the number of ducks that we in the United States use for food each year the rate at which the universe expands

the number of civilizations out among the stars with which we might communicate

Sunspots are darker than the regions of the Sun around them because they are cooler than the material around them (although still very hot compared to Earth temperatures) they are the shadows of the planets and asteroids seen on the bright surface of the Sun they are located in the corona and not on the photosphere they move much faster around the Sun than other material and thus heat up they consist of different elements than the rest of the Sun

they are cooler than the material around them (although still very hot compared to Earth temperatures)

How do astronomers know what the outer layers of the Sun are made of? the Sun's wind gives us an accurate measure of all the different elements in the Sun the surface layers of Mercury have been laid down by the Sun and are thus made of the same material as the Sun we send graduate students there to get samples we take an absorption line spectrum of the Sun, and the absorption lines tell us what elements are present in the outer layers several spacecraft with good shielding have approached the Sun and obtained samples

we take an absorption line spectrum of the Sun, and the absorption lines tell us what elements are present in the outer layers

From a scientific perspective, which of the following statements about life elsewhere in the universe is best supported by current evidence? we have good evidence that life exists on many planets around other stars there is no evidence for intelligent life anywhere, even on Earth the government has evidence (which it is not releasing) that there is at least one other intelligent life form on a planet orbiting another star while we have evidence of the building blocks of life elsewhere in the universe, we have no definite evidence about life around other stars at this time we only have evidence that life exists around three other stars

while we have evidence of the building blocks of life elsewhere in the universe, we have no definite evidence about life around other stars at this time