Meteors

• Meteor: The brief burst of light that results when a small, solid object naturally falls to Earth from space; meteors are also known as shooting stars or falling stars.

• Meteoroid: A small, solid object in space, usually a fragment from an asteroid or comet, that orbits the Sun.

• Meteorite: A solid object from space that has fallen to the surface of Earth.

• Cometary Meteoroids: These are fluffy little dust particles shed by comets.

• Asteroidal Meteoroids: Range in size from microscopic particles to boulders are chips from asteroids, which are rocky bodies that orbit the Sun.

• Micrometeorites: These are so small that they don’t create enough friction to burn up or disintegrate in the atmosphere, so they sift slowly down to the ground.

• When you see a "shooting star" outside on a night, it's most likely a sporadic meteor.

• A meteor shower when numerous meteors appear and all appear to have originated from the same location among the stars.

• Fireball: A dazzlingly bright meteor.

• Bolide: A fireball that explodes or produces a loud noise even if it doesn’t break apart.

• Radiant: The region of the sky or direction in space where a meteor shower appears to be coming from.

• The Quadrantids’ radiant is in the northeast corner of the constellation Bootes, the Herdsman.

• The Geminids are a meteor shower that seems to be associated with the orbit of an asteroid rather than a comet.

• The Leonids are an unusual meteor shower that occurs around November 17 every year, usually to no great effect.

Photographing Meteors

• Observe in a place that is as dark as possible and away from any urban lighting.

• Take photos of meteors only when the Moon is below the horizon.

• Use a sturdy tripod to prevent camera shake during exposure.

• Don't use a telephoto lens, use a wide-angle lens and set it to Infinity.

• To operate the camera shutter without shaking the camera and to take pictures at regular intervals throughout the night, use an intervalometer or "remote switch with digital timer."

• Aim the camera toward the direction that has the least distracting sky glow from the city or other lights, and raise it to about halfway up the sky from the horizon to the zenith.

• To choose the settings to use that night, spend some time taking test exposures. Several 10-second, 20-second, and 30-second exposures should be made. The goal is to ascertain how long an exposure can last without the skylight overexposing the image. It might be necessary to repeat this sequence of time exposures for each of the two or three ISO settings.

Comets

• Great blobs of ice and dust known as comets are common visitors from the solar system's outer regions. They appear as fuzzy balls trailing gassy veils as they slowly move across the sky.

• A comet is visible for days, weeks, or even months while a meteor is only visible for a few seconds.

• Within a radius of about 100 miles of the observer, meteors flash across the sky as they fall overhead. At distances of many millions of miles, comets scurry across the sky, frequently appearing to be almost motionless for over an hour or several hours unless you look through a telescope.

• Meteors occur frequently, while comets that are visible to the unaided eye only appear on average less than once per year.

• Comets: A stuck-together mixture of ice, frozen gases, and solid particles — the dust or “dirt”.

• Nucleus: The head of a comet.

• Coma: The gas and dust form a hazy, shining cloud around the nucleus.

• Types of Comet’s Tail:

  • Dust Tail: A smooth, sometimes gently curved appearance; usually a pale yellow.

  • Plasma Tail: A stringy, sometimes twisted, or even broken appearance; usually a blue color.

Comets History

• In 1965, Comet Ikeya-Seki could be seen next to the Sun in broad daylight if you held up your thumb to block the bright solar disk.

• In 1976, Comet West was visible to the naked eye even in the night sky over downtown Los Angeles, one of the worst places to see celestial objects.

• In 1983, Comet IRAS-Iraki-Alcock could be seen by the naked eye, actually moving in the night sky.

• In the 1990s, the bright comets Hyakutake and Hale-Bopp appeared out of the blue and were witnessed by millions of people worldwide.

• In 2007, Comet McNaught became the most brilliant comet since Ikeya-Seki in 1965, and for some lucky observers in the Southern Hemisphere, it was visible during the day.

• In 2011, Comet Lovejoy, spotted by a novice astronomer in Australia, traveled through the sun's extremely heated solar corona.

Artificial Satellites

• An artificial satellite is a creation that humans have launched into space and is orbiting the Earth or another celestial body.

• The artificial satellites that orbit the Earth display the weather, track El Nio, transmit network television shows, and keep an eye out for hostile nations launching intercontinental missiles. And they can also be used for astronomy.

• Hubble Space Telescope: It gives unparalleled views of the stars and distant galaxies and lets you view the universe in ultraviolet and infrared light that’s otherwise blocked by the thick layers of Earth’s atmosphere.

• Iridium satellite: It usually appears as a moving streak of light that gets remarkably bright and then fades after several seconds. It moves much more slowly than a meteor.