Characteristics of the flares of gamma rays detected from the Crab Nebula by the AGILE and
Fermi-LAT satellite instruments are compared with those of a gamma ray burst recorded by
several air shower arrays on February 23, 1989. It is demonstrated that though pulsar-periodicity
and energy spectra of emissions at 100 MeV (satellite gamma ray telescopes) and 100 TeV (EAS
arrays) are different, their time structures seem to be similar. Moreover, may be the difference
between “flares” and “waves” recently found in the Crab Nebula emission by the AGILE team
also exists at ultra-high energies.