NEID instrument lets scientists determine the density of distant planets

NASA and the National Science Foundation funded a new instrument called NEID. NEID is designed to help scientists to measure the masses of planets that are outside of our solar system. The tool observes the gravitational pull that planets exert on their parent stars.NASA says that information can help to reveal a planet's composition, which is one of the critical aspects of determining if the planet is habitable. NEID recently made its first observations on the WIYN 3.5-meter telescope at Kitt Peak National Observatory when it studied 51 Pegasi.

51 Pegasi was the first Sun-like star found to host an exoplanet and was discovered in 1995. The observatory is located in southern Arizona and is on land of the Tohono O'odham Nation. The pronunciation of NEID is meant to evoke a Native American word meaning "to see." The instrument studies planets using the radial velocity method where scientists study how the star wobbles slightly due to the orbiting planet's gravitational pull.

The more massive the planet orbiting the star, the more the star moves. With measurements of the diameter of the planet and its mass, scientists can determine its density to reveal if the planet is rocky or mostly gaseous. Scientists have been able to measure wobble speeds as low as about 3 feet per second, but NEID is capable of precision about three-times-finer.

NEID will confirm the presence and measure the mass of planets that are discovered by TESS. TESS detects planets using a different method than NEID. It will also investigate planet candidates found by other telescopes.