Exoplanet Interiors

"The first possible evidence of an exoplanet was noted in 1917..."

"The first confirmation of the detection occurred in 1992."

"As of 1 September 2023, there are 5,506 confirmed exoplanets..."

"...with 878 systems having more than one planet."

"The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and also much more about exoplanets, including composition, environmental conditions and potential for life."

"Transit photometry and Doppler spectroscopy have found the most..."

"...these methods suffer from a clear observational bias favoring the detection of planets near the star..."

"...thus, 85% of the exoplanets detected are inside the tidal locking zone."

"About 1 in 5 Sun-like stars have an 'Earth-sized' planet in the habitable zone."

"It can be hypothesized that there are 11 billion potentially habitable Earth-sized planets in the Milky Way..."

"The least massive exoplanet known is Draugr (also known as PSR B1257+12 A or PSR B1257+12 b), which is about twice the mass of the Moon."

"The most massive exoplanet listed on the NASA Exoplanet Archive is HR 2562 b..."

"Known orbital times for exoplanets vary from less than an hour (for those closest to their star) to thousands of years."

"Almost all of the planets detected so far are within the Milky Way."

"The nearest exoplanets are located 4.2 light-years (1.3 parsecs) from Earth and orbit Proxima Centauri..."

"The discovery of exoplanets has intensified interest in the search for extraterrestrial life."

"There is special interest in planets that orbit in a star's habitable zone (or sometimes called 'goldilocks zone'), where it is possible for liquid water...to exist on the surface."

"...the study of planetary habitability also considers a wide range of other factors in determining the suitability of a planet for hosting life."

"Rogue planets are those that do not orbit any star."

"The rogue planets in the Milky Way possibly number in the billions or more."