The Goldilocks Zone is the area from a star where any planets located there can support life. The conditions for life include liquid water on its surface with an atmospheric pressure high enough for it not to boil off.
A new definition of the Goldilocks Zone was recently devised because of new findings. It is based on improved atmospheric databases called HITRAN (high resolution transmission molecular absorption) and HITEMP (high temperature spectroscopic absorption parameters). The new definition has changed the increased the minimum distance from the star from 0.95 AU to 0.99 AU. The maximum distance from the star has changed from 1.67 Au to 1.7 AU. AU is the abbreviation for astronomical unit, which is the distance from the Earth to the Sun (93 million miles). The definition still does not take into account some effects that clouds in the atmosphere might have on the conditions to support life.
Scientists use the temperature of a star as one method of determining the possibilities of life on a planet outside the solar system, called an exoplanet. They recently found that the elements in a star can significantly change the location and length of its habitable zone.
NASA’s Kepler spacecraft mission is to hunt for planets. Analysis has found that one in five of the stars studied by Kepler could have planets the size of the Earth that are also in the habitable zone. The definition for a planet the size of the Earth is any planet from one to two times the area of the Earth. The habitable zone for a planet was defined as any planet that receives from one to four times the amount of sunlight that the Earth does. The Keck I telescope was used to find the exact radii of the exoplanets.
One method of finding planets is called the transit method. This method uses any dimming of the light coming from the star that might have planets orbiting it because it could be a planet blocking it. If a discovered planet has variations in its transit, it could also mean there is another planet causing it. If the star is wobbling it could also be a planet that is causing it. La Silla Observatory in Chile and the Keck telescope in Hawaii use this method.
Gravitational microlensing is used when a large object passes in front of a star using reference frames from the Earth’s standpoint. Astronomers have even found planets that soar through space without a host star. Telescopes on the Earth can use direct imaging to block the bright light coming from the distant star to search for planets in the area. Pulsar timing found the first planet outside the solar system in 1992. It uses the radio waves emitted by exploded stars to find the planets that orbit it.
Einstein’s special relativity can be used to find planets. The attraction discovered by Isaac Newton between the star and the planet causes the relativistic effect of the particles of light coming from the star called photons to collect in front of the star and make it brighter. Astrometry uses precise measurements of the changes in motion of the star that could be caused by planets orbiting it.
The elements that a star has can increase the habitable zone from its present area. Stars are usually composed mostly of hydrogen and helium, but if the star has metals or other elements in its composition it changes its habitable zone for planets. The elements oxygen, calcium, sodium, magnesium, aluminum, and silicon have been found to have an effect on a star’s habitable zone by scientists. Oxygen was found to have a significant effect on the zone.