Whenever we think about the planet we are inhibiting, a large massive body roaming around the sun comes to amaze us. However, Astrophysics are out to explore similar solar systems outside our solar system.
Now, scientists have detected a few planets outside our solar system and our looking forward to explain how they are formed.
The upcoming issue of Astrophysical journal will help and explain to astronomers that how planets are formed and arranged in the universe.
Extrasolar planets or exoplanets became the subject of scientific investigation in the mid nineteenth century. The first confirmed detection was made in 1990s; since 2002, more than twenty are discovered every year. Today scientists estimate 10% of Sun like stars having planets.
As of April 2006, nine of these ‘transiting planets’ observed by the current telescopes are very large gas planets orbiting very close to their stars. Called Pegasids, or ‘hot Jupiters,’ these planets have masses between 110 and 430 that of earth.
Leader Beth Biller of the University of Arizona and her colleagues worked specially to look for extrasolar gas giants for three years and surveyed about 54 nearby giants in their infancy. Theories suggest that young Jupiters are much brighter than the older ones and therefore easy to locate. Most of the extrasolar planets known were detected by using the radial velocity method (measurement of stellar wobbles caused by the gravitational pull of their respective stars).
These exoplanets, as suggested by theories, are formed inside the dusty disk that initially surrounds the stars.
Till today, we had core accretion and disk instability theories, which were though to lead all other theories. But now scientists feel that these theories are inadequate to explain the formation of gas giants out at distances beyond 20AU from their host stars, that is, at a distance more than 20 times the distance from the earth to the Sun.
One theory explains the formation of gas giant by the collapse of gas around a dense region while other involves the formation of solid metallic core, which later on attracts the gas surrounding it.
Alan Boss of the Carnegie Institute gave a statement based on the data collected by spacecraft Galileo which says that for core accretion a gas giant need to have a core of at least 10 earth masses and core mass of Jupiter is less than three earth masses.
Among many continuous studies, Richard Durisen of Indiana University supports a middle path which explains the formation of these gas giants with a mixing of gravitational instability and core accretion.
Thus, the debate is still waiting to be concluded with a suitable explanation, which the scientists can hope to be resolved in upcoming days.
Image Credit: Fas
Via: MSNBC
