Comets are celestial objects composed of frozen gases, rock, and dust. They are remnants from the formation of our solar system. Comets can be found in the Kuiper Belt and the mysterious Oort Cloud. Halley’s Comet and the Green Comet have had significant impacts on scientific understanding and perspective of comets.
What are comets?
Comets are composed of frozen gasses, rock and dust. Comets are made up of materials leftover from the creation of our solar system. NASA has identified 3,743 comets in our solar system.
Comets are many miles long while frozen, but as they heat up, they become larger than a planet and shoot out dust and gas.
There are two types of comets: short-period comets and long-period comets.
Short-period comets take less than 200 years to orbit around the sun. Short-period comets can be found at the Kuiper Belt, which is found past Neptune.
The Kuiper Belt (pronounced viper belt or Coy-per) was “predicted” by Gerard Kuiper, a Dutch astronomer. However, Gerard Kuiper believed that the Kuiper Belt no longer existed. It’s existence was confirmed and discovered by two astrologers in 1992.
Long-period comets take longer than 200 years to orbit the sun. The longest-known comet orbit is 250,000 years.
What is the Oort Cloud?
Long-term comets come from the Oort Cloud. The Oort Cloud is a “predicted collection of icy objects farther away than everything else in the solar system.”
No scientist has ever actually observed the Oort Cloud, but the prediction was made by a Dutch astronomer named Jan Oort in the 1950s.
Five spacecraft will eventually reach the Oort Cloud, but their power sources will run out hundreds of years prior.
The Green Comet 2023
The Green Comet recently passed Earth very closely in the beginning of February 2023. The Green Comet’s orbit takes about 50,000 years. The last time the Green Comet could be seen from Earth was in the Stone Age.
How Halley’s Comet Changed the World
One of the more well-known comets is Halley’s Comet. Halley passes by Earth every 76 years. Halley’s comet allowed astronomers to realize that comets can pass by Earth more than once.
Halley’s comet will be visible from Earth again on July 27, 2061.
Creative Challenge
This episode’s creative challenge is to imagine you are an astrophysicist and you found something new in outer space… what is it? What does it mean for Earth?
