Across
- 4. Two words for a measure of time by the stars, ---- marks the right ascension of stars on your local meridian at any moment.
- 5. The moment when a celestial object crosses the meridian and is thus at its highest above the horizon.
- 6. A supermassive black hole gorging on gas at the center of a distant galaxy.
- 10. The angle between the plane of an orbit and a reference plane.
- 13. The diameter of a telescope’s main lens or mirror
- 14. A measure of the atmosphere’s stability.
- 16. A slight tipping and tilting of the Moon from week to week that brings various features along the limb into better view.
- 20. When the Moon or a planet passes directly in front of a more distant planet or star.
- 22. A temporary dark blemish on the surface of the Sun that is a planet-size region of gas cooler than its surroundings.
- 24. Two words for a device for aiming your telescope that shows the sky as it appears to your unaided eye, without magnification.
- 25. The celestial equivalent of latitude, denoting how far (in degrees) an object in the sky lies north or south of the celestial equator.
- 26. The apparent offset of a foreground object against the background when your perspective changes.
- 27. The edge of a celestial object’s visible disk.
- 31. Sunlight reflected by Earth that makes the otherwise dark part of the Moon glow faintly. It’s especially obvious during the Moon’s thin crescent phases.
- 35. Two words for A concentration of mass so dense that nothing — not even light — can escape its gravitational pull once swallowed up.
- 38. A device that can be adjusted to show the appearance of the night sky for any time and date on a round star map.
- 39. The path among the stars traced by the Sun throughout the year.
- 40. Any prominent star pattern that isn’t a whole constellation
Down
- 1. Two words for a material that allows safe viewing of the Sun by blocking nearly all of its light.
- 2. Latin for “cloud.”
- 3. When Mercury or Venus crosses the disk of the Sun, making the planet visible as a black dot in silhouette, or when a moon passes across the face of its parent planet.
- 5. When the Moon or a planet appears especially close either to another planet or to a bright star.
- 7. A small telescope used to aim your main scope at an object in the sky.
- 8. The measure of how much an orbit deviates from being circular.
- 9. Two words for an entry in a catalog of 103 star clusters, nebulas, and galaxies compiled by a French comet hunter between 1758 and 1782.
- 11. The changing illumination of the Moon (or other body) over time. (more illuminated, between its new and full phases)
- 12. When an object moves in the reverse sense of “normal” motion.
- 15. Two words for the celestial equivalent of longitude, denoting how far an object lies east of the Sun’s location during the March equinox.
- 17. A timetable with celestial coordinates that indicates where a planet, comet, or other body moving in relation to background stars will be in the sky.
- 18. When the Moon or other body appears more than half, but not fully, illuminated.
- 19. Aligning the optical elements of a telescope so that they all point in the proper direction.
- 21. The imaginary north-south line that passes directly overhead.
- 23. Greek for “circle of animals.”
- 28. Two words for a few "beads" of sunlight, shining between mountain peaks and through the valleys along the Moon's edge in the moment before totality.
- 29. Two words for a star whose brightness changes over the course of days, weeks, months, or years.
- 30. The point in the sky that’s directly overhead.
- 32. Two words for two stars that lie very close to, and are often orbiting, each other.
- 33. A type of Newtonian reflector that uses a simple but highly effective wooden mount.
- 34. The changing illumination of the Moon (or other body) over time. (less illuminated, between its full and new phases)
- 36. Denotes an object near a celestial pole that never dips below the horizon as Earth rotates and thus does not rise or set.
- 37. The two times each year, near March 20th and September 22nd, when the Sun is directly overhead at noon as seen from Earth’s equator.