Across
- 1. Moons – also known as natural satellites – orbit planets and asteroids in our solar system. Earth has one moon, and there are more than 200 moons in our solar system. Most of the major planets – all except Mercury and Venus – have moons
- 3. The Universe is everything we can touch, feel, sense, measure or detect
- 4. Galaxies are sprawling systems of dust, gas, dark matter, and anywhere from a million to a trillion stars that are held together by gravity
- 7. A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit
- 9. solar system, assemblage consisting of the Sun—an average star in the Milky Way Galaxy—and those bodies orbiting around it: 8 (formerly 9) planets with about 210 known planetary satellites (moons); countless asteroids, some with their own satellites; comets and other icy bodies
Down
- 2. a group of galaxy clusters typically consisting of 3 to 10 clusters and spanning as many as 200,000,000 light-years
- 5. A star is any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. Of the tens of billions of trillions of stars in the observable universe, only a very small percentage are visible to the naked eye
- 6. Clusters are aggregates of atoms, molecules, or ions that adhere together under forces like those that bind the atoms, ions, or molecules of bulk matter
- 8. void space, a vacuum