Halley's Comet is making its mark almost everywhere -- even on stamps -- during this, its 29th recorded visit. The stamps offer a quick course of what astronomers hope to learn about the comet and recall visits of the past.

The United States paid its respects with a 36-cent aerogram that came out last week and that also marked the 150th anniversary of the birth of Mark Twain, whose life spanned visits of the comet.

Actually, the first stamp came out three weeks ago in Aitutaki, one of the larger Cook Islands, which issues its own stamps though a dependency of New Zealand. Also in the vanguard have been the Marshall Islands, Palau, Bermuda and the English Channel island of Jersey. More issues are expected before the comet completes its journey around the sun and its return swing by Earth.

Aitutaki has put out a pair of stamps reproducing the painting by Giotto that shows the comet over a traditional birth of Christ scene. In 1301, the painter was so awestruck by the sight of the comet that he substituted it for the Star of Bethlehem in the painting, "Adoration of the Magi."

The issue consists of a 95-cent for airmail to the United States and Asia and a $1.15 airmail for Europe and South America. The stamps also show two of the space probes sent up to study the comet, one by the European Space Agency and one by Japan. The European capsule is named "Giotto."

The issue from the Marshall Islands, focusing on current efforts to learn more about Halley's Comet, is made up of a se-tenant strip of five vertical stamps joined to each other to make an expanse of darkened sky above an island at the end of Kwajalein Atoll. The comet fills the sky across the five stamps. The island country, now issuing its own stamps, has been a Pacific trust territory of the United States ever since World War II.

The first of the five 22-cent stamps shows a NASA space shuttle bearing an astro-telescope for detailed observations. Shown on the second stamp is the Japanese spacecraft, Planet A, which will pass within 40,000 miles of the comet next March.

The middle stamp depicts the 11-nation European Space Agency's "Giotto," launched from French Guiana last July and scheduled to pass within 300 miles of the comet.

Two Soviet space probes appear on the fourth stamp. Vega I is to come within 6,000 miles of the nucleus and transmit information to "Giotto." Vega II is supposed to get within 2,000 miles.

The final stamp, instead of a spacecraft, shows Edmund Halley, for whom the comet is named.

The stamps have been produced in multicolor lithography in sheetlets of three se-tenant strips. Additional information or servicing of orders is provided by the Marshall Islands Philatelic Bureau, Box 59648, Washington, D.C. 20012.