main asteroid belt

基本解释

It is the first probe to enter orbit around an object in the main asteroid belt between Mars and Jupiter .
它是爲進入火星和木星之間的小行星帶中環繞一個天躰的軌道而進行的第一次探索。
The object, dubbed P/2010 A2, orbits the sun well within the main asteroid belt, according to observations taken as part of the Lincoln Near Earth Asteroid Research sky survey.
根據林肯近地小行星研究小組進行天空觀測時所記錄下來的觀察資料， P/2010 A2 在小行星帶主帶內部圍繞著太陽鏇轉。
huzhangao.blog.163.com
ScienceDaily (July 18, 2011) —NASA's Dawn spacecraft on July 16, 2011 became the first probe ever to enter orbit around an object in the main asteroid belt between Mars and Jupiter.
2011年7月16號，NASA的曙光探測器進入位於火星和木星之間的小行星帶，成爲進入這一地帶的第一個探測器。

Although downward-looking diagrams of the Main Asteroid Belt make it look incredibly dense, the region has significant gaps, clumps and clusters.
FORBES: Main Asteroid Belt No Remnant Of Exploded Planet
Abell says the best estimates now are that the Russian object was initially a rocky silicate asteroid that almost certainly originated from the main asteroid belt.
FORBES: NASA Eager To Analyze Russian Meteor Fragments
But astronomers have been unable to figure out how they get from the main asteroid belt between Mars and Jupiter to the vicinity of the Earth.
ECONOMIST: Celestial mechanics