October 9, 1984

During Sunday's debate on the economy and domestic affairs, President Reagan played his strongest card by asking Americans whether they were better off than they were four years ago - a question he had used devastatingly in his campaign against President Carter. Whereas, four years ago, Mr. Reagan had suggested that the answer was no, today he thinks it is obviously yes. But Mr. Mondale, well prepared for the President's card, finessed it by pitching the issue to the future. ''The real question,'' he said, is: 'Will we be better off? Will our children be better off?' '' Mr. Mondale's questions focused on the future growth of the economy and what might arrest that growth unless the budget deficits are narrowed. He thus raised the question of whether Americans will be looking forward or backward when they go to the polls on Nov. 6. And, apart from the merits of the arguments, Mr. Mondale appeared to have scored with the public with his greater command of economic data and logic.

Political analysts and poll takers on both sides asserted today that Walter F. Mondale's performance in the debate Sunday night had created a chance for him to revive his campaign against President Reagan. But poll takers agreed that it would be several days before it became clear if the Democratic nominee got significant help in cutting Mr. Reagan's lead of 15 to 23 percentage points in most national surveys of voting preference. On the campaign trail today, Mr. Reagan's re-election team appeared on the defensive for the first time in weeks, as the President's spokesman sought to explain a series of polls taken Sunday night showing that many voters believed that Mr. Mondale had made a better showing in the 90-minute debate broadcast on radio and televison. Aides to the President, who appeared today in Charlotte, N.C., and Baltimore, acknowledged that the Mr. Reagan's performance had been less than overwhelming, but they said Mr. Mondale had not achieved ''a knockout.'' (Page A29.)

The Dining Out Guide in Weekend on Friday, Sept. 28, gave an incorrect address for the Parioli Romanissimo restaurant. It is at 24 East 81st Street.

IN an effort to learn, at last, the true dimensions of the universe, several groups of astronomers are undertaking highly automated searches of the heavens for exploding stars, or supernovas. Each group hopes to scan several thousand galaxies every night in the hope of glimpsing light that has not been seen there before, evidence of an explosion. Underlying these efforts is the belief that the light from exploding stars may give astronomers their long-sought ''standard candle,'' enabling them to estimate distances to galaxies at the fringes of the universe. A standard candle is a light source whose intrinsic brightness is well enough known so that the extent to which its brightness has been dimmed by distance can be used as a yardstick. When lights are observed across a darkened landscape their relative distances can be estimated only when one knows how bright they would be up close.

Police Commissioner Benjamin Ward announced new police communications procedures yesterday that direct the transit police to notify the city police immediately whenever a transit officer loses contact with a partner or is involved in police action outside the transit system. The directive, which was announced without comment at Police Headquarters, came in the aftermath of the killing of a transit police officer, Irma Lozada, on Sept. 21 in the Bushwick section of Brooklyn. She was fatally shot after she and her partner, Nat Giambalvo, split up to chase a suspected chain-snatcher who fled from a subway station.