Spitzer Telescope is not old.

The Spitzer telescope is not old enough to confirm the atmospheric condition of an extrasolar planet. The planet, named LHS 3844b, was discovered last year by TESS, 48.6 light-years away and 1.3 times the radius of Earth, orbiting a smaller, cooler star. Spitzer observed its infrared radiation toward the sun and the back, and found that the temperature difference between the two is very large, and there is almost no heat exchange. This means that the planet may have no atmosphere. Picture is an art painting. Source: NASA/JPL-Caltech/R. Hurt (IPAC)