Across
- 3. A compound or activating form of energy (such as light or other types of radiation) that has a role to play in getting something done.
- 7. Having to do with atoms, the smallest possible unit that makes up a chemical element.
- 9. A massive group of stars bound together by gravity. Galaxies, which each typically include between 10 million and 100 trillion stars, also include clouds of gas, dust and the remnants of exploded stars.
- 10. Patterns formed by prominent stars that lie close to each other in the night sky. Modern astronomers divide the sky into 88 constellations, 12 of which (known as the zodiac) lie along the sun’s path through the sky over the course of a year.
- 11. The fourth planet from the sun, just one planet out from Earth.
- 12. Scattered fragments, typically of trash or of something that has been destroyed.
- 15. A broad and organized group of objects. Sometimes they are instruments placed in a systematic fashion to collect information in a coordinated way.
- 17. The name for a spinning, ultra-dense neutron star. When these stars rotate, they emit short, regular pulses of radio waves or X-rays
- 20. Energy that travels as a wave, including forms of light. Electromagnetic radiation is typically classified by its wavelength. The spectrum of electromagnetic radiation ranges from radio waves to gamma rays. It also includes microwaves and visible light.
- 22. A region of space having a gravitational field so intense that no matter or radiation (including light) can escape.
Down
- 1. (in physics) Devices for picking up (receiving) electromagnetic energy. (plural: antennae)
- 2. An adjective that refers to the cosmos — the universe and everything within it.
- 4. The force that attracts anything with mass, or bulk, toward any other thing with mass. The more mass that something has, the greater its ___
- 5. (in physics) A region in space where certain physical effects operate, such as magnetism (created by a magnetic field), gravity (by a gravitational field), mass (by a Higgs field) or electricity (by an electrical field).
- 6. The basic unit of a chemical element. Atoms are made up of a dense nucleus that contains positively charged protons and neutrally charged neutrons. The nucleus is orbited by a cloud of negatively charged electrons.
- 7. An area of astronomy that deals with understanding the physical nature of stars and other objects in space. People who work in this field are known as astrophysicists.
- 8. A substance formed from two or more atoms that unite (become bonded together) in a fixed proportion and structure.
- 13. (often used as a synonym for chemical) A compound is a substance formed from two or more chemical elements united in fixed proportions.
- 14. Something that is basic or serves as the foundation for another thing or idea.
- 16. (in chemistry) Each of more than one hundred substances for which the smallest unit of each is a single atom. Examples include hydrogen, oxygen, carbon, lithium and uranium.
- 18. supergiant A very large star that develops after helium-fueled fusion reactions have ceased in the core of a very massive star (a star more than 15 times the mass of our sun).
- 19. The measure how condensed an object is, found by dividing the mass by the volume.
- 21. Some outside influence that can change the motion of a body, hold bodies close to one another, or produce motion or stress in a stationary body.