Astronomy Check-in

4. The time it takes for the Sun to go from its highest position in the sky on one day to its highest position on the next day.
5. Time measured by using Earth's position relative to distant stars, instead of relative to the Sun. (Also called sidreal time.)
7. A fuzzy-looking patch of dust, gases, and ionized matter in interstellar space.
9. One of Jupiter's major moons. It has a heavily cratered surface.
12. A group of stars that is smaller than a constellation and may be part of a constellation.
13. The only known moon with a substantial atmosphere.
14. __________ solar time is the time based on the apparent solar time, averaged over the course of the year.
16. __________ solar time is time measured from the direct observation of the Sun.

1. A device that records the Sun's daily motion across the sky.
2. A spacecraft sent to study Jupiter and its moons. It was dropped into Jupiter's atmosphere to prevent an unwanted impact (and bacterial contamination) on Europa.
3. A group of stars that forms a pattern in the sky.
6. A spacecraft that visited Saturn and its moons, capturing amazing images. It was also dropped into the atmosphere to prevent an unwanted impact with a moon.
8. The art and science of mapping celestial bodies.
10. The largest of Neptune's moons. Scientists believe that it was a Kuiper Belt object from beyond Neptune's orbit, captured by Neptune's gravity.
11. A pair of spacecraft which are currently the most distant man-made objects from Earth.
15. The first spacecraft to orbit two extraterrestrial objects. It had a special solar-electric engine that powered it to 25,700 mph.