| GREENHOUSE | The ___ effect describes how the radiation from a planet's atmosphere warms the surface of that planet by preventing the heat from escaping into space |
| CHEERIO | Named after the breakfast cereal, the ... effect describes how small wettable objects clump together |
| ANTIFLASH | Describing paint on an aircraft, used to reflect thermal radiation from a nuclear explosion (4-5) |
| CIRRI | They help warm the surface of Mars |
| IMIN | "That plan sounds good to me!" |
| PTAS | Orgs. that plan some book fairs |
| DEAL | "Does that plan sound good?" |
| VACANTLY | How inanely describes how the lights are on but nobody's at home! (8) |
| BANG | Physical theory that describes how the universe began, Big _ Theory (4) |
| VENUES | Scenes of action from a planet in the east |
| ELEPHANT | Gets a huge animal from a planet he revisited (8) |
| EARTH | Soil from a planet (5) |
| SECOND | Unit of time defined as "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom" (6) |
| SALTATION | Term used to describe how the kangaroo hops with both feet pushing off the ground at the same time |
| ULTRAVIOLET | Type of radiation invisible to the human eye. Constant exposure to this radiation from the sun can be bad for the skin. |
| OZONE | ____ layer, region of the upper atmosphere absorbing ultraviolet radiation from the sun (5) |
| SOLARFLARE | A brief powerful eruption of intense high-energy radiation from the sun's surface |
| NIELSBOHR | 1922 Nobel physics laureate, for work on “the structure of atoms and [...] the radiation emanating from them” |
| CIRCLE | Meaning "ring", a closed curve resembling such; the shape of a big top's arena; a planet's orbit; a figure in magic; or, a parallel of latitude (6) |
| SOLARFLARES | Brief powerful eruptions of particles and electromagnetic radiation from the sun's surface (5,6) |
