You searched for: “planetary
Word Entries at Get Words containing the term: “planetary
geoengineering, planetary engineering
1. The artificial manipulation of the environments of the earth; especially, as a means of counteracting global warming.
2. Proposals to deliberately manipulate the earth's climate to counteract the effects of global warming from greenhouse gas emissions.

So far, no large-scale geoengineering projects have been undertaken, nor has a consensus been reached that geoengineering is desirable.

President Obama’s science adviser, Dr. John Holdren, after giving his first round of interviews (April 10, 2009) immediately caused a ruckus by airing his thoughts on geoengineering; the large-scale tinkering with the earth’s climate to chill runaway global warming climate changes that could potentially slow or reverse global warming.

Holdren emphasized that even if he personally thinks it prudent to start evaluating geoengineering options, he still believes that the most pressing concern should be curbing greenhouse gas emissions to prevent global warming from reaching catastrophic proportions.

—Compiled from information found in the article,
"Obama’s Science Adviser Kicks Up a Fuss Over Geoengineering"
by Eliza Strickland; Discover, Science, Technology, and the Future
Web Site, April 10, 2009.
This entry is located in the following unit: Geology or Related Geological Terms + (page 5)
planetary albedo
The fraction (approximately 30 percent) of incident solar radiation that is reflected by the earth-atmosphere system and returned to space, mostly by scattering from clouds in the atmosphere.
This entry is located in the following units: Astronomy and related astronomical terms (page 19) Geography Terms + (page 5)
planetary astronomer
Someone who studies planets, moons, and planetary systems, in particular those of the solar system and the processes that form them.

It includes the studies of objects ranging in size from micrometeoroids to gas giants, with the objectives of determining their compositions, dynamics, formations, interrelations, and histories.

This entry is located in the following unit: Astronomy and related astronomical terms (page 19)
planetary astronomy
The investigation of the solar system and planetary systems using both ground and spacecraft-based observations.

It includes the study of Kuiper belt objects, dwarf planets, Titan, other icy satellites, extra-solar planetary systems (from brown dwarfs to stellar disks), and the occasional inner solar system body.

This entry is located in the following unit: Astronomy and related astronomical terms (page 19)
planetary boundary layer, PBL
The lower part of the earth's atmosphere that is directly influenced by conditions on the surface; such as, evapotranspiration.

Its height is variable and ranges from 100 to 3,000 meters.

This entry is located in the following unit: Astronomy and related astronomical terms (page 19)
planetary conjunction
Planetary conjunction takes place when a planet is closely aligned with another celestial object; such as, the moon, a star, or another planet.
This entry is located in the following unit: Astronomy and related astronomical terms (page 19)
planetary nebula
1. The cloud of expanding gas surrounding a star that has blown off its outer layers, possibly in a nova stage.
2. A shell of gas thrown off by a star at the end of its life.

Planetary nebulae have nothing to do with planets. They were named by William Herschel, who thought their rounded shape resembled the disk of a planet.

After a star; such as, the sun has expanded to become a red giant, its outer layers are ejected into space to form a planetary nebula, leaving the core as a white dwarf at the center.

This entry is located in the following unit: Astronomy and related astronomical terms (page 19)