Planetoids:  1 | 2 | 3 | 4 | 5


Asteroids, aslo called minor planets, or planetoids, are large, irregularly-shaped objects that circle the Sun, primarily between the orbits of Mars and Jupiter (the Asteroid belt), and ranging in size from tens of meters to hundreds of meters in diameter. The photo to the right shows Vesta, the second largest asteroid (in terms of mass) in the Solar System. It has a diameter of 525 km, or 326 miles.

For a virtual tour of Vesta, please click this link: Vesta Trek

Click here to learn about a class of near-Earth asteroids known as Apollo Asteroids.


4 Vesta


The word comet is derived from the Latin word cometes, itself coming from the Greek word kometes, meaning comet, but originally 'long-haired'. A comet is a celestial body consisting of a nucleus of ice and dust. It has a highly eccentric orbit around the Sun, originating from the outer regions of the Solar System, either in the Kuiper Belt, or the Oort Cloud; and it is only observed in that part of its orbit when it is relatively near the Sun. As it nears the Sun, a comet will develop a long vapour trail of dust and gas streaming behind it.




A meteoroid is a an object floating in outer space ranging in size from a grain of sand to a boulder 10-50 metres across. Once a meteoroid enters the Earth's atmosphere and becomes visible, it is considered a meteor. Most meteors burn up before they reach the ground. The remnant of a meteor that lands on the ground, if not vaporized by the impact, is called a meteorite. Anything larger than a meteoroid is considered an asteroid.

Meteorite Slice



Any object in the Solar System orbiting the Sun at a greater average distance than Neptune is a Trans-Neptunian Object (TNO). A prime example of a TNO is be the dwarf planet Pluto. Although these objects are hard to observe, over 1200 TNOs have now been identified. NASA's New Horizons spaccraft is currently en route to an encounter with a TNO known as 2014 MU69 located deep within the Kuiper Belt. New Horizons is expected to arrive at its target on January 1, 2019.

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  1. 01/03  First Meteorite Composed Of Martian Crust Found
  2. 01/09  Apophis
  3. 01/22  Asteroid Mining
  4. 02/15  Meteor Injures Hundreds In Russia
  5. 02/15  Meteorite Fragment Lands In Lake
  6. 02/15  Asteroid Passes Close To The Earth
  7. 09/10  Near-Earth Asteroid Is Really Comet


  1. 03/26  First Ring System Around Asteroid Discovered
  2. 07/17  Rosetta Captures Revealing Photo of Comet 67P Churyumov-Gerasimenko
  3. 08/06  Rosetta Arrives At Comet Destination
  4. 08/11  Comets Forge Organic Molecules In Their Dusty Atmospheres
  5. 08/16  Comet's Surface Variations Photographed By Rosetta
  6. 10/13  NASA Prepares Mars Spacecraft For Comet Encounter
  7. 10/15  Philae Landing Gets Green Light
  8. 10/15  Potential KBOs For Extended New Horizons Mission
  9. 11/04  Philae Landing Site Named Agilkia
  10. 11/12  Probe Makes Historic Comet Landing


  1. 04/07  Asteroid Juno Observed Traveling Through Space
  2. 04/08  Origin Of Annama Meteorite Determined
  3. 07/01  Rosetta Spacecraft Sees Sinkholes On Comet
  4. 07/30  Surface Of Comet Churyumov-Gerasimenko Harder Than Expected
  5. 08/31  Ceres: The Planet That Wasn't
  6. 09/09  Ceres’ Bright Spots Seen In Detail
  7. 11/03  Radar Images Provide Details On Halloween Asteroid


  1. 03/09  Rosetta: Type Of Ice Reveals The Age Of Comets
  2. 04/01  Comet 67P Presented In Silhouette
  3. 05/27  Comet 67P Contains Ingredients For Life
  4. 06/17  Earth Has An Asteroid Companion
  5. 09/14  Giant Meteorite Unearthed In Argentina
  6. 09/16  Origin Of Minor Planets' Rings Revealed
  7. 10/31  Catalog Of Known Near-Earth Asteroids Tops 15,000
  8. 11/09  Comet Chury Much Younger Than Previously Thought


  1. 01/24  Urban Collection Of Comptemporary Micrometeorites
  2. 01/31  Hunting For Iron Meteorites In Antarctica
  3. 02/22  Surprising Dunes On Comet Chury
  4. 09/14  Could Interstellar Ice Provide Answer To Birth Of DNA?
  5. 11/17  Interstellar Asteroid is Given A Name
  6. 12/12  Interstellar Asteroid Checked For Alien Technology


  1. 02/11  Oumuamua: Tumble Hints At Violent Past