Astronomy

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Stars appear to pulsate and twinkle in the night sky due to the refraction of light through the Earth's atmosphere. When the light from a star enters the atmosphere, air molecules bounce and deflect the light rays, slightly altering the apparent position and intensity of the star.

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  • What is the farthest star from Earth?

    Q: What is the farthest star from Earth?

    A: Scientists will never know the farthest star from Earth, as the star is so far away that its light has not, nor will ever, have enough time to reach Earth. Even the stars within the visible universe are far too numerous to count, but the farthest one that humans have ever detected is about 55 million light years away. This incredibly distant star is called SDSS J 122952.66 +112227.8.
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  • What is terrestrial navigation?

    Q: What is terrestrial navigation?

    A: Terrestrial navigation is a field of study that helps sea-faring people locate points at sea and on the land. Similarly, it involves being able to identify the position of the ship anywhere in the world. Students are instructed in the use of nautical charts, compass corrections and voyage planning.
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  • What causes a lunar eclipse?

    Q: What causes a lunar eclipse?

    A: Lunar eclipses are caused when the moon travels through the Earth’s shadow. Complete lunar eclipses are rare, but partial lunar eclipses may occur up to four times per year.
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  • What is the sky made of?

    Q: What is the sky made of?

    A: Four layers of the earth's atmosphere containing various gases make up the composition of the sky. The layers of the atmosphere are divided into the troposphere, the stratosphere, the mesosphere and the thermosphere. The atmosphere's divisions occur according to temperature fluctuations.
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  • What is outer space made of?

    Q: What is outer space made of?

    A: Outer space contains a low density of particles, primarily hydrogen gas, along with electromagnetic radiation. Many people, however, mistakenly believe outer space is a complete vacuum. The term "outer space" is used mainly to distinguish the space between planets from the planets and their airspace.
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  • What is an elliptical orbit?

    Q: What is an elliptical orbit?

    A: Elliptical orbits are the paths taken by objects as they fly around a massive object, such as the sun or Earth. Such orbits are not round as is commonly supposed; instead, they orbit the massive body in the shape of an ellipse. Ellipses are like circles that have been elongated slightly, and they are also referred to as ovals.
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  • Are stars bigger than the sun?

    Q: Are stars bigger than the sun?

    A: Stars exist that are both bigger and smaller than the sun. The sun has a radius of 1.4 million kilometers and, relative to other stars, is an average size.
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  • What is the difference between a solar and lunar eclipse?

    Q: What is the difference between a solar and lunar eclipse?

    A: A solar eclipse occurs when the Moon passes between the Sun and Earth so that the Moon's shadow falls on the Earth. A lunar eclipse occurs when the Earth passes between the Sun and Moon and the Sun casts the Earth's shadow on the Moon. Both events happen only when the Sun, Moon and Earth are aligned.
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  • What did Galileo discover?

    Q: What did Galileo discover?

    A: After Galileo built his first telescope in 1609, he observed and described the landscape of the moon, discovered four of the moons of Jupiter, discovered the phases of Venus, and discovered sunspots. Galileo's discovery of sunspots supported the idea of heliocentrism, a model that places the sun at the center of the universe with the planets orbiting around it.
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  • What is the purpose of the Hubble space telescope?

    Q: What is the purpose of the Hubble space telescope?

    A: The Hubble Space Telescope was created to capture detailed images or objects that are too far away to be viewed with conventional telescopes. The Hubble's instruments create images that are far superior to those of terrestrial observatories, which suffer from the effects of atmospheric distortion.
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  • How many times bigger is the sun than the earth?

    Q: How many times bigger is the sun than the earth?

    A: According to NASA, the sun’s diameter is approximately 100 times larger than the diameter of the earth. The earth would have to be lined up 100 times in order to stretch across the face of the sun.
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  • How did Galileo impact the world?

    Q: How did Galileo impact the world?

    A: Galileo's main impact on the world was his improvement upon the telescope and being the first to use it in the science of astronomy. He also supported the Copernican system that stated that planets orbit the sun rather than the Earth as the Catholic Church said at the time. His other contribution was to contradict Aristotle's teachings that heavier objects fall faster than lighter ones.
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  • What are meteorites made of?

    Q: What are meteorites made of?

    A: The meteorites that land on earth can be made of stone, iron or stony iron. A few meteorites are made of volcanic glass, but scientists aren't sure that all of these meteorites are extraterrestrial in nature. They believe some of these meteorites are formed when material from an impact crater liquefies and then turns to glass as it's ejected into the atmosphere.
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  • What is the difference between equinox and solstice?

    Q: What is the difference between equinox and solstice?

    A: A solstice is defined as the point during the Earth's orbit around the sun at which the sun is at its greatest distance from the celestial equator, while an equinox is at its least distance. A solstice is characterized by either an extremely long night or an extremely short day.
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  • What is a planetarium?

    Q: What is a planetarium?

    A: A planetarium is a facility designed to replicate the features of the universe in the night sky. Similar to a museum or science center, planetariums are developed in communities to offer education and entertainment to people curious about the field of astronomy. Visitors typically pay admission fees to enter just as they would at a theater or zoo.
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  • What are heavenly bodies in space?

    Q: What are heavenly bodies in space?

    A: Natural objects found outside of the Earth's atmosphere, such as planets, stars, moons, comets, meteors and asteroids, are some of the heavenly bodies in space. It is believed that there are other forms of heavenly bodies or objects in space that are yet to be discovered and explored.
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  • How did the solar system form?

    Q: How did the solar system form?

    A: The formation of the solar system began with the creation of the sun after an exploding supernova caused spherical accumulation of dust particles and gas in a huge swirling cloud called nebula. Planets and other components of the solar system formed in the flat plane of the rotating disc of dust.
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  • Why is it that stars twinkle but planets do not?

    Q: Why is it that stars twinkle but planets do not?

    A: Stars twinkle because they are point light sources. Passing through the atmosphere, the small beam of light constantly shifts by bouncing off particles in the air. Planets are closer, so they appear as discs, with the shifting of light from one side cancelling out the other.
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  • Where does the sky end?

    Q: Where does the sky end?

    A: The sky ends at the Karman line, which is located at about 67 miles above sea level. Above this line, space begins. However, technically, the sky does not end so much as the atmosphere, or sky, thins until there is no oxygen left.
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  • How long will the sun last?

    Q: How long will the sun last?

    A: The sun will last approximately another five billion years, according to NASA in 2012. The sun's light and heat are generated by the burning, or fusing, of hydrogen gas into helium gas.
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  • What causes day and night to happen?

    Q: What causes day and night to happen?

    A: The Earth goes through a constant cycle of day and night because it rotates on an axis. At any point in time, only about half of the Earth is facing the sun, while the other side is facing away from it. The side that is facing the sun is illuminated (day) while the side facing away from the sun remains dark (night).
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