ANALYSIS OF THE MARSHALL ISLANDS FIREBALL OF FEBRUARY 1, 1994

On February 1, 1994, a large meteoroid impacted over the Pacific Ocean at 2.6 degrees N, 164.1 degrees E. The impact was observed by space b ased IR sensors operated by the US Department of Defense and by visibl e wavelength sensors operated by the US Department of Energy. During e ntry the object broke into several pieces, one of which detonated at 3 4 km and another at 21 km altitude. The entry velocity of the object i s estimated to be 24-25 km/sec. Based on the visible wavelength data, the integrated intensity of the radiated energy of the fireball was ap proximately 1.3 x 10(13) joules. Assuming a 6000 K black body and a 30 % efficiency for the conversion of the kinetic energy of the body into visible light, we estimate the mass of the body to be between 1.6 x 1 0(5) kg and 4.4 x 10(6) kg, and to have a diameter of between 4.4 and 13.5 meters. The object entered at a 45 degrees angle, traveling on a heading of approximately 300 degrees, i.e. from the southeast to the n orthwest. Calculations using a gross-fragmentation model indicate that the body was most likely a stony object larger than 10 m with an Apol lo orbit prior to impact.