The Solar System - Word Search - PUZZLE #46 HALLEY'S COMET - August 2025

PUZZLE #46 - HALLEY'S COMET 

IN-CONTEXT WORD DEFINITIONS

Gases: The coma and tail of Halley's Comet are composed of various gases, including water vapor, carbon dioxide, carbon monoxide, and other volatile compounds. These gases are released from the nucleus as the Sun's heat causes the comet's ices to sublimate (turn directly from solid to gas).

Perihelion: This is the point in a celestial object's orbit where it is closest to the Sun. Halley's Comet's perihelion occurs approximately every 75-76 years, and it is at this point that the comet is brightest and most active, as the Sun's heat causes significant outgassing and tail formation. Its most recent perihelion was in 1986.

Aphelion: This is the point in a celestial object's orbit where it is furthest from the Sun. Halley's Comet's aphelion takes it far beyond the orbit of Neptune, into the depths of the outer Solar System. At aphelion, the comet is a dormant, icy body with no visible coma or tail.

Edmond Halley: An English astronomer who, in the 17th and 18th centuries, studied the orbits of several comets. He famously deduced that the comets observed in 1531, 1607, and 1682 were in fact the same object and successfully predicted its return in 1758. The comet was subsequently named in his honor. [1]

Giotto: The European Space Agency (ESA) launched the Giotto probe in 1985 to intercept Halley's Comet during its 1986 perihelion. Giotto flew within 596 kilometers (370 miles) of the comet's nucleus, providing the first close-up images of a comet's nucleus and detailed data on its composition and activity.

Vega: The Soviet Union's Vega 1 and Vega 2 spacecraft were also part of the international effort to study Halley's Comet in 1986. They performed flybys of the comet's nucleus before the Giotto probe, providing valuable data that helped guide Giotto's approach.

Meteor Shower: This astronomical event occurs when Earth passes through the trail of dust and debris left behind by a comet or asteroid. The particles enter Earth's atmosphere and burn up, creating streaks of light known as meteors.

Eta Aquariids: This is one of two annual meteor showers associated with Halley's Comet. It occurs in early May each year when Earth passes through the comet's debris trail. The meteors appear to radiate from the constellation Aquarius.

Orionids: This is the second annual meteor shower linked to Halley's Comet. It occurs in late October when Earth once again intersects the comet's orbital path and passes through its debris. The Orionids appear to radiate from the constellation Orion.

Secret Word: Halley's Comet, like other comets, develops one or more of these as it approaches the Sun. These are formed when solar radiation and the solar wind vaporize the ice and dust from the comet's nucleus. It is usually broad and curved, while the ion (or gas) component is typically straight and points directly away from the Sun due to the solar wind.