How do we know we are in recession ?

It's not as if a recession lands like some typhoon or shakes like an earth quake. The noticable point in 2008 crisis was the Lehman Brothers crashing down and mass layoffs happened during that period. Are we gonna expect something like this time too ? $S&P 500 Index(.SPX.US)$ $SPDR S&P 500 ETF(SPY.US)$ $Invesco QQQ Trust(QQQ.US)$ $iShares Russell 2000 ETF(IWM.US)$ $Nasdaq Composite Index(.IXIC.US)$ $Dow Jones Industrial Average(.DJI.US)$ $Imperial Petroleum(IMPP.US)$ $Camber Energy(CEI.US)$