High Quality Content by WIKIPEDIA articles! In addition to known extrasolar planets, there are many planet candidates whose existence is more or less uncertain, or they are now known not to exist. On February 2, 2011, the Kepler Space Observatory Mission team released a list of 1235 (unconfirmed) extrasolar planet candidates. 68 candidates are "Earth-size" (smaller than 1.25 of the radius of Earth); 54 candidates are thought to be in the "Habitiable Zone (HZ);" Six candidates (KOI 326.01, KOI 701.03, KOI 268.01, KOI 1026.01, KOI 854.01, KOI 70.03 - Table 6) in the HZ are less than twice the size of the Earth; one candidate in the HZ is "Earth-size" (namely, KOI 326.01 at 0.85 the radius of Earth). Nonetheless, there are 53 unconfirmed extrasolar planets listed here.