Sentences with phrase «small comet nucleus»

A strike by a large asteroid or small comet nucleus (1 kilometer or greater) is but one of several kinds of independent high energy events that could destroy humanity and probably a significant number of other species as well.

Not exact matches

Because the nucleus is so small, these jets act like rocket engines, spinning up the comet's rotation, Jewitt said.

Drawing on his data from the Hubble observations, Li estimates that the nucleus — the solid body of the comet itself — is no more than about 2.5 miles (4 kilometers) across, smaller than what many astronomers initially expected for such an energetic comet.

Although the comet's tail may ultimately stretch millions of kilometers through the solar system, its nucleus is likely smaller than New York's Central Park.

«The icy small bodies warm up as they approach the Sun, and the ice sublimes to form a coma [a dense cloud of gas and dust particles around a nucleus] and often a tail, making the comets observable,» she explained.

Moreover, this material is then ejected and hardly contributes to the formation of the smaller bodies that form a new generation of comet nuclei.

Since the comet nucleus is very small, at a diameter of 4 kilometres, the summer zone is only about one kilometre away from the winter zone.

Added to this, the MRO discovered that the comet nucleus was smaller than thought with a diameter of only 1.2 miles (2 km) and rotates once every eight hours, and the radar images it took were smeared due to energy levels ten times greater than normal.

As a comet approaches the Sun, a small fraction of the snowball (or nucleus) evaporates, forming a gas and dust cloud, called a coma, around the nucleus.