By Associated Press:

Today is Tuesday, July 31, the 212th day of 2018. There are 153 days left in the year.

Today’s Highlight in History:

On July 31, 1991, President George H.W. Bush and Soviet President Mikhail S. Gorbachev signed the Strategic Arms Reduction Treaty in Moscow.

In 1919, Germany's Weimar Constitution was adopted by the republic's National Assembly.

In 1954, Pakistan's K2 was conquered as two members of an Italian expedition, Achille Compagnoni and Lino Lacedelli, reached the summit.

In 1957, the Distant Early Warning Line, a system of radar stations designed to detect Soviet bombers approaching North America, went into operation.

In 1964, the American space probe Ranger 7 reached the moon, transmitting pictures back to Earth before impacting the lunar surface.

In 1971, Apollo 15 crew members David Scott and James Irwin became the first astronauts to use a lunar rover on the surface of the moon.

In 1972, Democratic vice-presidential candidate Thomas Eagleton withdrew from the ticket with George McGovern following disclosures that Eagleton had once undergone psychiatric treatment.

In 1989, a pro-Iranian group in Lebanon released a grisly videotape showing the body of American hostage William R. Higgins, a Marine lieutenant-colonel, dangling from a rope.

In 1992, the former Soviet republic of Georgia was admitted to the United Nations as its 179th member. Thai Airways Flight 311, an Airbus A310, crashed while approaching Tribhuvan International Airport in Nepal; all 113 people aboard died.

Ten years ago: Scientists reported the Phoenix spacecraft had confirmed the presence of frozen water in Martian soil. 

Five years ago: President Barack Obama's national security team acknowledged for the first time that, when investigating one suspected terrorist, it could read and store the phone records of millions of Americans. Voters in Zimbabwe went to the polls in national elections that were won by President Robert Mugabe amid opponents' allegations of fraud.