FORBES - NASA reports that its official tally of extrasolar planets has hit the 6,000 mark. This thirty-year milestone has been in the works since two little known Swiss astronomers, Michel Mayor and Didiez Queloz, first detected 51 Pegasi b.
The first of the so-called “hot Jupiters” to be detected, “51 Peg” is a gas giant planet half the mass of our own Jupiter on a crazily short 4.2-day orbit around its parent star, 51 Pegasus, some 50 light years away. In contrast, our planet Mercury, which is scorchingly hot itself, orbits the sun in just under 88 days.
Confirmed planets are added to the count on a rolling basis by scientists from around the world, so no single planet is considered the 6,000th entry, NASA says. The number is monitored by NASA’s Exoplanet Science Institute in Pasadena, with 8,000 more awaiting confirmation, notes the space agency.
The most important thing that exoplanets bring to the planetary science table is vast numbers, Stephen Kane, a planetary geophysicist at the University of California in Riverside, tells me via email. This enables a statistical analysis of planetary properties across various axes, such as planet mass, size, composition, age, and formation processes, Kane tells me.