November 11 () –
A new instrument at Hawaii’s Keck Observatory is primed and ready to search for and characterize hundreds and ultimately thousands of exoplanets, including the little ones.
The Keck Planet Finder (KPF) instrument, which uses the “wobble” or radial velocity method of searching for planets, achieved the so-called first light on November 9, which means that it captured its first data from the sky, in this case from the planet Jupiter. While KPF will routinely observe stars, the KPF team chose to celebrate KPF’s planet-hunting capabilities by directly observing Jupiter in our own solar system.
“The advent of KPF marks an important and exciting step forward in our ability to advance the search to eventually find habitable Earth-like planets around other stars,” he says. it’s a statement Hilton Lewis, director of the Keck Observatory. “We have been awaiting the arrival of KPF for almost a decade and are delighted to be able to take our already successful exoplanet discovery program to the next level.”
The search for small planets similar to Earth, the most promising in the search for extraterrestrial life, has been limited due to the minuscule effects these planets have on their host stars.
KPF detects planets by looking for the periodic motions of their host stars caused by the planets as they orbit and gravitationally “pull” on the stars. When stars move from side to side, or wobble, their light shifts in the same way that the sound of a siren changes frequency depending on whether the noise is moving away from you or towards you, known as doppler shift.
KPF will detect planets by looking for this stellar wobble in the spectra of the stars (a spectrum shows the different frequencies of light from a star). The less massive the planet, the less wobble that occurs. The instrument’s state-of-the-art technology means it can detect planets as small as Earth, and even smaller in some cases.
It can also detect Earth-mass planets in the habitable zones of smaller, cooler stars, although it still can’t see them in the habitable zones of Sun-like stars. A habitable zone is the region around a star where temperatures are suitable for liquid water, a necessary ingredient for life as we know it.
In addition to discovering new planets, the instrument will determine the compositions of up to thousands of known planets and solve mysteries about the amazing diversity of planetary systems identified so far. KPF will also discover nearby planets that are ideal candidates for future portraits by other telescopes, such as the planned Thirty Meter Telescope, which could take direct images of planets orbiting close to their stars.
