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Astronomy
Question | Answer |
---|---|
NASA stands for | National Aeronautics and Space Administration |
NASA initiative to land a man on the moon, inaugurated in 1961 and comprised of 17 missions; from 1967-1972 | Apollo program |
First manned landing on the moon's surface | Apollo 11 |
Number of lunar landings by the US | 6 |
Number of men who have walked on the moon | 12 |
Final Apollo flight; occurred in December 1972 | Apollo 17 |
layer of gases surrounding a planet or any body of sufficient mass, including a star; the layer's shape is maintained by gravity | atmosphere |
central part of a planet or star | core |
a large planet that consists primarily of gases instead of rock. | gas giants |
number of gas giants in the solar system | 4 Jupiter, Saturn, Uranus, Neptune |
process through which heat radiated from a planet's surface is absorbed and then radiated outward in all directions, even downward. Surface temperatures beneath the atmospheric gases are raised | greenhouse effect |
Earth has this effect but Venus has a much more extreme version of this effect | greenhouse effect |
An orbit of the Earth at an altitude of 90-620 miles. All manned space flights, except Apollo, and most artificial satellites are in this region | Low Earth Orbit |
On Earth, a layer around 1800 miles thick, between the outer part of the planet's core and the surface (crust) | mantle |
Areas of basaltic lava on the Moon's surface. Early astronomers wrongly identified these as areas of water. 16% of the Moon's surface. Dark patterns that make up "the Man in the Moon" | Mare (Latin for sea) |
Colloquially known as a shooting star. The name given to a streak of light caused by rock or dust burning up as it falls through a planet's atmosphere | meteor |
the appearance of several meteors in short succession | meteor shower |
A meteoroid that has landed on the surface of a moon or planet | meteorite |
a rocky body, smaller than an asteroid, in our Solar System | meteoroid |
aka a natural a satellite, an astronomical body that orbits a planet or smaller body, known as its primary. | moon |
largest moon in the Solar System | Ganymede (Jupiter) |
second largest moon in the Solar System | Titan (Saturn) |
the release of gas that was absorbed, frozen, or otherwise trapped in a surface. for example, in an ocean or area of rock on the surface of a planet | outgassing |
the embryos or initial formations of planets, formed in a protoplanetary disk (cloud of dust & gas surrounding a new star) They form from the collision of smaller planetestimals | protoplanet |
Where are several ____________ in orbit around a star, they collide to form one or more planets | protoplanets |
any loose mixture, such as soil or pieces of stone, that cover solid rock. Found on the Earth, the Moon, and on other planets, moons, and asteroids | regolith (Greek for blanket and rock) |
AKA a planetary ring, a disk-shaped formation of dust and particles orbiting a planet. Most celebrated is Saturn's, though Jupiter, Neptune and Uranus have this | ring system |
lacking in density. Used of a planet's atmosphere | tenuous |
the mean distance between the Earth and the Sun, roughly 93 million miles. | astronomical unit (AU) |
very thin cloud of gas and dust surrounding the heart or nucleus of a comet. | coma |
The heart of a comet is a ball of ice and rock particles called an ___ ____________ or dirty snowball | icy conglomerate |
The heart of a comet is a ball of ice and rock particles called an icy conglomerate or _______ __________ | dirty snowball |
As the comet nears the inner Solar System and is more strongly heated by the Sun, some of the dust & ice is vaporized, creating the _____ | coma |
In the Sun, an area between the radiation zone (nearer the core) and the solar photosphere, through which energy passed by convection | convective zone |
Hotter material rises from the bottom, carrying energy, then sinks again after cooling; the cooling material heats up again as it sinks and then rises once more in a rolling process | convection (convective zone of the Sun) |
A short-period comet named after this English astronomer | Halley's Comet (officially known as 1P/Halley; named for Edmond Halley) |
He correctly calculated in 1705 that the comets seen in 1531, 1607, and 1682 were one returning comet | Edmond Halley |
The brightest short-period comet visible to the naked eye and is visible every 75-76 years. Known since at least 240 BC | Halley's Comet |
It was seen during the Norman Conquest of England in 1066 and was represented in the Bayeux Tapestry that recorded the conquest. | Halley's Comet |
Last seen in 1986, it will appear again in 2061 | Halley's Comet |
Doughnut-shaped region in the outer Solar System, billions of miles from our Sun, containing small bodies and dwarf planets, including Pluto. | Kuiper Belt (30-55 AU from the Sun) |
Because their orbit lies beyond that of Neptune, these small bodies and dwarf planets are often called ______ _____________ __________ | trans-Neptunian objects |
The combination of two atomic nuclei to form a heavier nucleus, accompanied by the release of energy. This powers the Sun and other active stars | Nuclear Fusion |
Spherical cloud in the outer Solar System, beyond the Kuiper Belt, that could contain up to 2 million frozen bodies. The farther reaches of this area mark the limit of the Sun's gravitational attraction. The boundary of the Solar System | Oort Cloud |
Astronomers believe that most comets originate in the _____ _______ | Oort Cloud |
The Meteor shower occurring annually from July 23 - August 20, so called because the area from which the meteors appear to fall lies in the constellation, Perseus | Perseids |
The dust and debris of the Perseids meteor shower come from the comet _____ ______ | Swift-Tuffle |
The Perseids are mostly visible in the _______________ ____________ | northern hemisphere |
rotating disk of gas and dust surrounding a newly formed star in a developing star system. Planets form from the gas and grains of dust | protoplanetary disk |
comet with an orbital period around the Sun of less than 200 years | short-period comet |
The outer atmosphere of the Sun, not normally visible because it is one million times less bright than the visible solar protosphere | solar corona |
It can be seen during a total solar eclipse, when the brightness of the solar disk is blocked by the Moon, or using a coronagraph instrument, which blocks the light coming from the solar disk in order to enable study of the solar atmosphere | solar corona |
the visible outer layer of the Sun, only around 60 miles thick. Sunspots, faculae (bright areas), and granules (cellular features) are visible on this layer | protosphere |
a vast ball of gas of great mass (held together by gravity) that generates heat and light through nuclear fusion reactors at its' core | star |
dark spots on the solar photosphere that result when magnetic activity limits convection, creating areas where the very high temperature is partly reduced | sunspots |
His paradigm-shifting heliocentric theory stated the Sun, not the Earth, was at the center of the universe | Nicolaus Copernicus |
the starting point of space & time in an explosion from a single, extremely hot and extremely dense point | Big Bang |
According to various competing theories, the Universe began with the ____ _____ | Big Bang |
AKA the Big Freeze. One projected end for the expanding universe. Galaxies will drift away, stars will burn out, galaxies will become exhausted and the Universe will become large, dark and cold | Big Chill |
The Universe will expand until it reaches a critical point, then begin to contract, becoming more dense and hotter and finally reaching an infinitely dense, hot point | Big Crunch |
Matter will be torn apart by the dark energy that pushes the expansion of the universe | Big Rip |
a diffuse field of radiation-the first light released in the aftermath of the Big Bang that spread out through the expanding universe | Cosmic Microwave Background |
Discovered in 1964; it established the primacy of the Big Bang over other theories of the origin and state of the Universe | Cosmic Microwave Background |
the study of the birth, size, shape, growth and projected end of the Universe | cosmology |
energy that fuels the expansion of the universe | dark energy |
unseen matter whose gravitational effects are detected on visible matter, galaxies, and large-scale structures in the Universe | dark matter |
the 4 basic forces effective in the Universe: gravitational force, electromagnetic force, strong nuclear force, weak nuclear force | fundamental forces |
the rate of expansion of the Universe | Hubble Constant |
Extremely powerful explosion, releasing substantially more energy than a supernova-that gives issue to gamma ray bursts of long duration | hypernova |
intensely short, very fast expansion that occurred in the aftermath of the Big Bang. Followed by a period of relatively gradual expansion | inflation |
Thought to have occurred for just an infinitesimally small fraction of a second, between 10^-38 and 10^-36 seconds after the Big Bang | inflation |
the distance that light travels in one year: 5.9 trillion miles (9.5 trillion km) | light-year |
a theory suggesting that the effects of the gravity may be longer lasting and stronger than generally thought | MOND: Modified Newtonian dynamics, |
These effects rather than dark matter hold together galaxies and other clusters that would otherwise fall apart | MOND: Modified Newtonian dynamics, |
quasi-stellar radio sources. | quasars |
astronomers first thought these were radio stars, but then discovered that the radio waves were emitted by a galaxy with a bright nucleus consisting of a supermassive black hole | quasars |
stars that emit radio waves, such as pulsars | radio stars |
New matter is continuously created in a constantly expanding Universe, forming new stars and galaxies, while old galaxies and stars become unobservable as the Universe expands | steady-state theory |
This theory first proposed by James Jeans and then developed by Fred Hoyle is a rival theory to the Big Bang | steady-state theory |
The Universe has a constant average density and no end or beginning in time. This theory has been discredited | steady-state theory |
Eclipsing binary star in the constellation Perseus. Once ever 69 hours, one star eclipses the other for about 10 hours. This means that its light appears to dip, noticeably enough to be seen by the naked eye | Algol |
In many cultures, the star is associated with evil. Hebrew tradition calls the star Satan's Head and the ancient Greeks saw it as the winking eye of a Gorgon held by the hero Perseus | Algol (Arabic for the demon) |
Region in which matter has been highly compressed and as a result gravity acts with such force that everything in the area, even light, is drawn powerfully in. They come into existence when a massive star is dying | black hole |
the most massive and hottest type of star; it gives off bright blue light, often seen in regions of spiral galaxies where stars are being born | blue giant star |
3800 light years distant in the constellation Scorpius. A planetary nebula given its descriptive name because its vast gas clouds resemble the wings of this creature | Butterfly Nebula (aka NGC 6302) |
a cloud of dust or gas in interstellar space | nebula |
flash of high-frequency electromagnetic radiation, typically released during a supernova | gamma ray burst |
one with a significantly larger luminosity and radius than a main sequence star | giant star |
typically as much as 1000 times luminous as our Sun and 10-100 times ours Sun's radius | giant star |
Even larger, more massive and more luminous stars are labeled | supergiants and hypergiants |
those on the main sequence of the Hertzsprung-Russell diagram of color and brightness | main sequence stars |
Red giant star 200-400 light years away in the constellation Cetus. An example of a pulsating variable star. Its brightness varies on a regular cycle 332 days in length | Mira (aka Omicron Ceti) |
extremely dense start created from exhausted nuclear fuel following the final explosion (supernova) of a massive star at the end of its life | neutron star |
explosion in a white dwarf star caused when the star takes on matter from a twin in a binary star system and reignites, leading to runaway nuclear fusion on the surface of the white dwarf | nova explosion |
less powerful and bright than a supernova. name comes from Latin for 'new' because previous invisible white dwarf stars reappear when a nova occurs and may be taken for a new star | nova explosion |
a cloud of gas expelled into space by a giant red star. term derived from William Herschel | planetary nebula |
Herschel thought the clouds he viewed were similar to gas giant Uranus, although these nebulae form around dying stars and have no connection to planets | planetary nebula |
a cooler star, of lower mass compare to a giant blue star | red giant star |
A planetary nebula in the constellation of Lyra. It consists of a cloud of ionized gas expelled into space by a red giant star | Ring Nebula (aka Messier 57) |
explosion at the end of a star's life, when the core of a massive star collapses to form a black hole or a neutron star | supernova |
Type 1A occurs when a white dwarf star takes in material from a companion in a binary star system, until passing a critical mass (1.4 times our Sun), it explodes | supernova |
structure created by a supernova explosion, containing the material of the star that exploded and any interstellar material swept along with it | supernova remnant |
highly dense remnant of a star, created after a red giant star swells and gives issue to a vast nebula, exposing the star's core-which cools and grows dim | white dwarf star |
These stars vary in brightness in different ways and for many reasons | variable stars |
stars often form in pairs | binary stars |
The surface brightness and color of stars is plotted on the ________________ __________ diagram-the key to how stars live and die | Hertzsprung-Russell |
Formed in supernova explosions, ___________ are neutron stars that reveal their presence as pulsating radio stars | pulsars |
The nearest galaxy to our own. A spiral galaxy 2.5 million light-years away in the Andromeda constellation and contains one trillion stars | Andromeda Galaxy |
Galaxy which we live in | Milky Way Galaxy |
Type of star that varies between a compressed and an expanded state. | Cepheid variable |
The stars (which have a mass of between 5 & 20 times that of our Sun) expand when pressure builds up, then contract because pressure is lower in the star's expanded state. | Cepheid variable |
These stars are used by astronomers to establish extragalactic distances | Cepheid variable |
An icy body with a coma (temporary atmosphere) and a tail in orbit around the Sun that becomes visible when sufficiently close to the Sun | comet |
The tail points away from the Sun, while the curved coma follows its' path | comet |
higher density clouds in the interstellar medium, in which stars are formed | diffuse star formation nebulae |
galaxy in the form of an ellipsoid. One of 3 galaxy types identified in 1936 by Edwin Hubble along with lenticular and spiral galaxies | elliptical galaxy |
a system bound together by gravity, containing stars, clouds of dusts, gas in the interstellar medium, and dark matter | galaxy |
group of stars tightly bound in a spherical shape by gravity, that orbits the core of a galaxy. 150-160 of these in the Milky Way, containing some of the oldest stars in the galaxy | globular cluster |
the matter that fills the space between the star systems within a galaxy. Consists of gas and dust; from these materials, new stars are formed | interstellar medium (ISM) |
type of disk galaxy with a central group of stars (called a bulge) similar to a spiral galaxy, but lacking the spiral arms | lenticular galaxy |