NASA reported today that hundreds of previously unidentified distant planets have been discovered by its famed Kepler telescope. The discovery of 715 confirmed exoplanets in more than 300 planetary systems means that the number of known planets in the universe has now nearly doubled. The new Kepler data will be published in an upcoming iteration of the Astrophysical Journal.
Kepler observers report that none of the new planets appears to be any larger than the well-known Neptune and that just four of them may be within what is considered to be “the habitable zone” of their respective stars. This means that they exist at a distance that at least allows the possibility of the existence of life-sustaining liquid water on their surface. The planets cannot be directly seen as they exist tens of trillions of miles away or more, instead their presence has been verified to a more than “99 percent confidence level,” making few other specifics known about them.
The hundreds of newly identified planets all exist in what are known as multi-planet systems and scientists reviewing the NASA Kepler telescope data are finding that most of these multi-planet systems are quite different from Earth’s own solar system. While Earth’s solar system consists of planets spaced at relatively large distances from each other and a good distance away from the sun, other multi-planet systems appear to consist of planets spaced closer together and closer to their star as well.
NASA scientists say that they are now beginning to believe that planets distant from their stars are actually quite rare. Some of the planets spotted by the Kepler telescope are close enough to their stars that it would appear, based on what is currently known about the way in which both planets and stars form, that they must have been formed elsewhere in the universe and migrated to their current locations over a period of time.
This isn’t the first remarkable news about the universe to result from Kepler’s work. Last fall Kepler scientists asserted that based on the space telescope’s observations of one limited portion of the sky, as many as one in five stars similar to the Earth’s sun has a planet of similar size and habitability to Earth, creating the possibility that there could be tens of billions of planets like earth in just the Earth’s galaxy.
The Kepler space telescope was first launched on March 7, 2009 and came at a cost of $600 million. Over the course of the past nearly five years it has made a name for itself as being the instrument most skilled at discovering the existence of new planets, taking credit for a total of 961 confirmed, and keeping an eye on thousands more candidate planets, more than 90 percent of which are expected to be confirmed as well. Despite experiencing a malfunction with its pointing system last year, the Kepler team has continued its impressive body of work. Today’s announcement by NASA of the discovery of hundreds of new planets, however, marks the largest batch to be confirmed by NASA.
By Michele Wessel