NASA Logo, National Aeronautics and Space Administration

Science Q & A

Q — What is the difference between TESS and Kepler?
— TESS and Kepler address different questions. Kepler answers how common are true Earth analogs. TESS answers where are the nearest transiting rocky planets?

Q — How will TESS build on Kepler's discoveries?
— TESS is an all-sky survey. Kepler only looks at 1/400 of what TESS will observe in the sky. Exoplanets that are identified by TESS can be potentially followed up and researched further by ground based telescopes. TESS will look at stars that are nearer and brighter than the ones Kepler has studied. Many Kepler exoplanets cannot be followed up by ground based telescopes for mass measurements since they are too far away. With both the size and the mass of an exoplanet, you can learn the density, and TESS opens that door because it looks at the nearest and brightest stars, where we can follow up with ground-based telescopes.

Q — Will TESS be able to look for atmospheres and biomarkers?
— TESS itself as a survey mission cannot, it is the first step to identify the presence of an exoplanet. After the TESS Science Team identifies the best candidates for rocky planets, large telescopes, such as the James Webb Space Telescope or ground based telescopes, can then be used to characterize atmospheres.

Q — What do you hope will come out of the TESS mission?
— Finding rocky exoplanets with solid surfaces at the right distance from their stars. These could be the best candidates for follow-up observations that fall within the "habitable zone" and be at the right temperatures for liquid water on their surface.

+ Find out more about why TESS?

NASA logo
Goddard Space Flight Center