  Considerable progress has been made in recent years in observations of
atmospheric signatures of giant exoplanets, but processes in rocky exoplanets
remain largely unknown due to major challenges in observing small planets.
Numerous efforts to observe spectra of super-Earths, exoplanets with masses of
1-10 Earth masses, have thus far revealed only featureless spectra. In this
paper we report a 4-$\sigma$ detection of variability in the dayside thermal
emission from the transiting super-Earth 55 Cancri e. Dedicated space-based
monitoring of the planet in the mid-infrared over eight eclipses revealed the
thermal emission from its dayside atmosphere varying by a factor 3.7 between
2012 and 2013. The amplitude and trend of the variability are not explained by
potential influence of star spots or by local thermal or compositional changes
in the atmosphere over the short span of the observations. The possibility of
large scale surface activity due to strong tidal interactions possibly similar
to Io, or the presence of circumstellar/circumplanetary material appear
plausible and motivate future long-term monitoring of the planet.
