cận địa

Friendly

The Vietnamese word "cận địa" translates to "perigee" in English, and it is primarily used in astronomy.

Basic Definition:

• Cận địa refers to the point in the orbit of a celestial body (like the Moon or a satellite) where it is closest to the Earth.

Usage Instructions:

• You can use "cận địa" in discussions related to astronomy, space science, or when talking about the orbits of celestial bodies. It is not commonly used in everyday conversation but is important in specific scientific contexts.

Example:

• "Điểm cận địa của Mặt Trăng là khoảng cách gần nhất mà Mặt Trăng đến Trái Đất." (The perigee of the Moon is the closest distance that the Moon gets to the Earth.)

Advanced Usage:

• In advanced astronomy discussions, "cận địa" might be used in calculations involving the gravitational effects of the Earth on the Moon or satellites, such as discussing orbital mechanics or the effects of perigee on tides.

Word Variants:

• Cận địa can be paired with other words to create phrases:
  • Điểm cận địa: perigee point
  • Khoảng cách cận địa: perigee distance

Different Meaning:

• In a more general sense, "cận địa" can also imply "nearby" or "close to the ground" in non-scientific contexts, but this usage is less common.

Synonyms:

• While "cận địa" specifically refers to the perigee, it can be contrasted with "điểm viễn địa" (apogee), which is the point in an orbit farthest from the Earth.

Summary:

To sum up, "cận địa" is an important term in astronomy that denotes the closest approach of a celestial body to Earth. It’s used primarily in scientific contexts, especially in discussions about orbits and distances in space.

Academic

1. Điểm cận địa (thiên văn học)
2. Perigee