Flashcards in Earth and Space Science Deck (104)
How many known extrasolar planets exist as of 2008?
The solar system contains at least ____ dwarf planets
5 (Ceres, Pluto, makemake, haumea, Eris)
A small solar system body that orbits the sun and, when, close enough to the sun, exhibits a visible coma (atmosphere) or a tail
Loose collections of ice, dust, and small rocky particles measuring a few kilometers or tens of kilometers across.
Comets that are thought to originate in the Kuiper Belt, or associated scattered discs, which lie beyond the orbit of Neptune.
Short period comets
Comets that are believed to originate at a much greater distance from the sun, in a cloud (the Oort Cloud) consisting of debris left over from the condensation of the solar nebula.
Long period comets
They are sometimes called minor planets/planetoids, and are bodies--primarily the inner solar system--that are smaller than planets but larger than meteoroids, excluding comets
What is the difference between asteroids and comets?
Visual appearance: when discovered, comets show a perceptible coma while asteroids do not.
What is the distance from the earth to the sun?
The earth travels in orbit that is slightly oval (elliptical) so the distance ranges from 91.5 to 94.5 million miles
The degrees east or west of the prime meridian through Greenwich, England
The degrees north or south of the equator
What is the explanation to why we have seasons?
The seasons of the year are the consequence of the earths equatorial plane being tilted about 23 degrees from the orbital plane
In each hemisphere at noontime, the sun is near the zenith during _____, and low in the sky during ______.
In each hemisphere, at noontime, the sun is near the zenith during SUMMER, and low in the sky during WINTER
What is the distance between the moon and the earth?
The phase of the moon when it is in conjunction with the sun and visible from earth, or shortly thereafter when it appears as a slender crescent.
The moon is less than one half illuminated by the sun but less than one quarter illuminated.
During this phase of the moon, fifty percent of it is illuminated and visible from the earth. It occurs after the Crescent phase and before the Waxing Gibbous phase.
First quarter (moon phase)
When the moon appears to be more than one half but not fully illuminated by direct sunlight. This phase happens when the moon is between 45 and 90 degree angle with respect to the earth and sun
Waxing Gibbous moon
The phase of the moon in which it is visible as a fully illuminated disk
Moon phase that occurs when the moon appears to be more than one half illuminated (but not fully illuminated); when the moon is between a 90 and 135 degree angle with respect to the earth and sun.
Waning Gibbous moon
Darkens the moon as the earth passes between it and the sun, casting a shadow on the moon.
Takes place when the moon passes between the earth and the sun, with the moon blocking the sunlight for about 2 minutes. (A total eclipse may only be seen from the small zone on the earth)
A huge ball of incandescent gases. It's mass is more than 300,000 times that of the earth (it's volume could engulf a million earths)
What are the two principal constituents of the sun?
The lightest elements, hydrogen and helium (gases undergoing nuclear fusion to heavier elements with the release of prodigious quantities of energy)
The sun's atmosphere is divided into the ______________ with explosive prominences and the __________, a glowing halo only visible during a solar eclipse
Inner chromosphere; outer corona
Bodies similar to the sun but immensely distant
Astronomers have calculated the distance to many of the closest stars by measuring the __________, a slight shift in apparent position against the background of more distant stars as the earth travels around the sun
Interstellar distances are described in ___________. ( the distance light travels in one year)
Light years. (The nearest star is 4 light years away!)
Huge systems of stars