Geocentric model explanation in terms of the Earth's revolution about the sun. In 1838, astronomer Friedrich Wilhelm Bessel measured the parallax of the star 61 Cygni successfully, and disproved Ptolemy's claim that parallax motion did not exist. This finally confirmed the assumptions made by Copernicus, providing accurate, dependable scientific observations, and conclusively displaying how distant stars are from Earth. A geocentric frame is useful for many everyday activities and most laboratory experiments, but is a less appropriate choice for solar system mechanics and space travel. While a heliocentric frame is most useful in those cases, galactic and extragalactic astronomy is easier if
Term life insurance basis over a specific period of time. Term life insurance can be contrasted to permanent life insurance such as whole life, universal life, and variable universal life, which guarantee coverage at fixed premiums for the lifetime of the covered individual unless the policy is allowed to lapse. Term insurance is not generally used for estate planning needs or charitable giving strategies but is used for pure income replacement needs for an individual. Term insurance functions in a manner similar to most other types of insurance in that it satisfies claims against what is insured if the premiums are up to