Orbital period change of Dimorphos due to the DART kinetic impact.

The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, the secondary of near-Earth binary asteroid (65803) Didymos, and changing the orbital period of Dimorphos. A change in orbital period of approximately 7 min was expected if the incident momentum from the DART spacecraft was directly transferred to the asteroid target in a perfectly inelastic collision, but studies of the probable impact conditions and asteroid properties indicated that a considerable momentum enhancement (β) was possible. In the years before impact, we used lightcurve observations to accurately determine the pre-impact orbit parameters of Dimorphos with respect to Didymos.

Femtosecond optical parametric oscillator based on periodically poled stoichiometric LiTaO3 crystal.

Efficient optical parametric oscillation is demonstrated in periodically poled stoichiometric lithium tantalate crystal pumped by a mode-locked Ti:sapphire laser. The optical parametric oscillator (OPO) delivers a maximum average power of more than 345 mW in signal and 180 mW in idler beams. The OPO is continuously tunable across the 940-1350 nm wavelength range in its signal branch, delivering nearly transform-limited 160-180 fs pulses.