By: Michael Totten
A long-term comet is a periodic comet which returns to the sun every 200 years or longer. Some long-term comets have orbital periods which are measured in the thousands or millions of years. Designation In the Cometary Designation System, a long-term comet is named for...
Why the moon is bright though the albedo is low
By: Christyl Rivers
The brightness of a full moon has inspired centuries of creation myth, poetry and even vampire and werewolf mini series and movies. Yet few people know that the shining moon actually reflects less light than the planet Venus. The albedo of the moon, it’s...
Comparing Venus to Earth
By: Christyl Rivers
Venus and earth are similar in size, in proximity to the sun, and in gravitation. But living conditions there compared to earth are very different indeed. Venus represents the best planetary cautionary tale that earth science can access in regard to warning human occupants of...
How and why comet tails appear
By: Rex Trulove
Comets are both strange and interesting objects. They vary in size and brightness, with some being so dim they can barely be seen with a telescope and others that are so bright that they can be easily seen with the naked eye. One of the...
By: Michael Totten
A comet is a collection of dust, rocks, ice, and frozen gases which is between half a mile and 100 miles in diameter. A comet's tail does not exist for nearly all of the comet's orbit. It won't appear at all until the comet's orbit...
Guide to the Orionids Meteor Shower  
By: Leigh Goessl
The Orionids Meteor Shower is expected to make its appearance as it customarily does in the second half of each October. In 2012, this cosmic illumination that stems from Halley's Comet is expected to arrive mid-week with it peaking on Sun., Oct. 21. While some...
By: Christyl Rivers
The planet Venus has the highest albedo in the solar system, yet the moon appears brighter to people on earth because it is so much closer than Venus. Albedo refers to the reflected brightness of a surface, or planetary body, in this case. Albedo comes...
Do you believe that aliens have already visited our planet?
By: Christyl Rivers
Aliens have visited earth many times. But so far, it is always in the imaginations of a species desperate for answers and connection to the cosmos. Absence of evidence is not evidence of absence. Nevertheless, no truly compelling evidence such as a fossil, a...
By: Robin Lamb
The planet Venus is a ‘femme fatale’; beautiful and alluring, and yet secretive and deadly. Revered by the ancients and named by the Romans for their goddess of love and beauty, the Earth’s nearest neighbouring planet appears as a bright ‘star’ in...
By: Mace Moulton Spiegel
Ethyl mercaptan, also known as ethanethiol, is an organic compound (liquid at room temperature) with a strong, unpleasant odor. It is often added to propane, butane, or liquid petroleum gas, which are otherwise odorless, to make it easier to detect gas leaks. It is flammable...

 

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