Israeli airstrikes hit multiple Iran nuclear sites. Here's what we know about them.

The Israeli military targeted Iranian nuclear facilities, research scientists and senior military commanders in dozens of preemptive airstrikes early Friday morning in what it dubbed "Operation Rising Lion."

The strikes — which the Israel Defense Forces said included dropping "over 330 different munitions" on more than 100 targets in Iran — prompted Iran to launch about 100 missiles at Israel in a retaliatory attack later Friday. The IDF said its Iron Dome missile defense system intercepted most of the missiles, and U.S. officials confirmed that the United States helped Israel intercept Iranian missiles. 

IDF spokesman Brig. Gen. Effie Defrin claimed intelligence showed "the Iranian regime has made significant progress in achieving nuclear capability and its ability to act against us," calling it an emerging and existential threat to Israel. Secretary of State Marco Rubio said the U.S. was not involved in Israel's airstrikes on Iran.