Astronomy Final Exam

Scientists used what telescopes to observe and confirm the existence of the TRAPPIST-1 exoplanet system?

A small ground-based telescope, called TRAPPIST, a large ground-based telescope called the Very Large Telescope, and the Spitzer Space Telescope

The exoplanet Kepler-186f is the first earth-size exoplanet discovered in the habitable zone around another star, but what is the main difference between this planet and the Earth?

Its parent star is cooler and dimmer than our Sun

The new revised Kepler mission, or K2, uses what additional effect to stabilize it?

Pressure from sunlight

Based solely on detection number of frequency, Kepler has found the most of what type of exoplanet?

Super Earths or Sub-Neptune sized planets

Select the statement that best describes the TRAPPIST-1 system

TRAPPIST-1 is a system of seven earth-sized planets, with three located in the habitable zone

The Kepler Space Telescope uses which method to detect exoplanets?

Transit Method

if we were to get extremely lucky, what type of structure did the video identify as a far out possibility of detecting around an advanced alien civilization?

a ring world, a giant artificial structure built around a star

The Milky Way does not rotate like a solid wheel, instead it obey's Kepler's 3rd law. This results in an effect called:

differential galactic rotation

When we observe distant galaxies, we are essentially doing what?

looking back in time, seeing what the universe looked like much early on

Possibility for why we don't see thousands of dwarf galaxies around the Milky Way

many of the other dwarf galaxies got disrupted and / or accumulated over time by the growing Milky Way galaxy most dwarf galaxies are just too faint to see many of the first dwarf galaxies that formed contained lots of very massive stars that blasted out all of the gas and stars except for in only the most massive sub halos, so those are the only dwarf galaxies left today some of the sub halos are just too small, and therefore never formed stars, making them completely dark

Galaxies grow and change with time by what main mechanism?

mergers of galaxies and accretion of smaller galaxies

According to a research study using Kepler data, what fraction of Sun-like stars in our galaxy are thought to have Earth-like planet in the habitable zone? This fraction translates to how many total planets?

one-fifth; 40 billion

What method of searching for ET is most related to the Drake equation?

passively listening to signals from stars and planets

what is meant by the moment of first light?

point in the universe's history when it went from being completely dark to the first sources of light (first stars) turning on

In the article about the possibility of life on other worlds it discusses how the Revised Drake equation focuses on what, as compared to the original Drake equation which looked to estimate the number of advanced alien civilizations?

the fraction of planets with gases in their atmospheres that can be produced by lifeforms

In the Seager equation, (the revised Drake equation), what two parameters are we most confident about their values at this time? In other words, which parameters do we feel very confident about their values, compared to others where we may just have to guess?

the number of stars bright enough to observe and the fraction of planets that can be observed

One main limitation of the microlensing technique for detecting exoplanets is?

the planets detected by microlensing will not be observed again