Click on image for full size
Courtesy of NASA and the University of Iowa.
Snowballs Entering The Earth's Atmosphere?
News story originally written on June 20, 1997
New evidence has just been found that supports the theory of interplanetary snowballs spraying the Earth's upper atmosphere. NASA's Polar spacecraft and its Visible Imaging System (VIS) are responsible for the findings.
Dr. Louis Frank of the University of Iowa led the team in research endeavors. The research team found that these snowballs could be up to the size of a small house! They are not however dangerous to life on Earth, because the snowballs disintegrate while they are still in the upper atmosphere. Frank noted, "They break up and are destroyed at 600 to 5,000 miles above the Earth. In fact, this relatively gentle 'cosmic rain' --which possibly contains simple organic compounds--may well have nurtured the development of life on our planet."
The objects, though they may contain organic material, are mostly composed of water. They are thought to be comet-like objects which contain frozen water, and so are termed "dirty snowballs." These snowballs are entering the atmosphere at a rate of 5-30 snowballs per minute, or thousands of snowballs in a given day.
Though this finding is still somewhat controversial, these objects may explain the existence of previously found "atmospheric holes." What is not controversial is the success of the Polar spacecraft's first year in orbit.
Last modified July 18, 2002 by Lisa Gardiner.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, ranging from seismology
, rocks and minerals
, and Earth system science
You might also be interested in:
It was in the early 80's that the Small Comet theory came into being. During this time, Louis A. Frank working with John Sigwarth noticed black spots on Dynamics Explorer I's data. Reluctant to just ignore...more
It was another exciting and frustrating year for the space science program. It seemed that every step forward led to one backwards. Either way, NASA led the way to a great century of discovery. Unfortunately,...more
The Space Shuttle Discovery lifted off from Kennedy Space Center at 2:19 p.m. EST, October 29th. The sky was clear and the weather was great as Discovery took 8 1/2 minutes to reach orbit for the Unitied...more
A moon was discovered orbiting the asteroid, Eugenia. This is only the second time in history that a satellite has been seen circling an asteroid. A special mirror allowed scientists to find the moon...more
Will Russia ever put the service module for the International Space Station in space? NASA officials are demanding an answer from the Russian government. The necessary service module is currently waiting...more
During a period of about two days in early May, 1998, the ACE spacecraft was immersed in plasma associated with a coronal mass ejection (CME). The SWICS instrument on ACE, which determines unambiguously...more
J.S. Maini of the Canadian Forest Service has referred to forests as the "heart and lungs of the world." Forests reduce soil erosion, maintain water quality, contribute to atmospheric humidity and cloud...more