以表彰他們發現海王星以外物體及描述其特性，對研究太陽系最初之形成及追尋短週期彗星來源提供寳貴資料。
朱維特(Jewitt) 和劉(Luu) 在1993 年發現海王星以外物體。在此之前，人們對太陽系遠處，在海王星軌道至奧特雲(Oort cloud) 之間的空間，所知甚少。(海王星離太陽30天文單位，而奧特雲則離開太陽超過一萬天文單位，為長週期彗星之源。) 例如，在這個區域到底有些甚麼物體？從朱維特和劉的硏究，我們現在得知，在30至50天文單位之間的區域，充滿了數以萬計的冰凍物體，直徑超出50公里。這些物體因吸積而匯集，吸積過程屬於行星形成的早期。但受到某些現在尚未確定的過程影響，它們的速度分佈增濶，以至吸積過程終止。其後，由於它們互相遠離，很少發生碰撞，因而沒有進一步的演變。所以這些物體為我們提供了最佳的記錄，讓我們可以了解行星形成過程中早期的情況。
這搜索與研究直至發現第一顆海王星外物體，是歷時五年努力的成果。在進行搜索的初期，朱維特為麻省理工學院教授，而劉為他的研究生。
Astronomy is arguably the oldest science. Observations of the motion of heavenly bodies date back more than 2,500 years. Nevertheless, as recently as 1992, immediately prior to the detection of the first Kuiper belt objects (KBOs) by Jewitt and Luu,1 little was known about the contents of the solar system beyond 30 AU.2 Distant bodies are dim because they reflect little sunlight back to Earth and our most powerful telescopes can only image small angular regions at a single pointing. Thus searches for widely-spaced, faint images are tedious and resource intensive. Before Jewitt and Luu’s discovery, Pluto and its large satellite Charon were the only directly detected bodies orbiting beyond Neptune.
Comets provide indirect information about reservoirs of bodies beyond 30 AU. Although comets are directly detected only when they come within a few AU, their orbits can be traced back to show where they came from. By 1950 it had been established that most long-period comets were visitors from distances in excess of 10,000 AU and that their orbits were randomly oriented with respect to the mean orbit plane of the solar system. These facts led Jan Oort to hypothesize that comets are stored in an enormous spherical cloud beyond 10,000 AU and that gravitational deflections by nearby stars are responsible for injecting those we detect into the inner solar system. Oort’s model is widely accepted and the hypothetical comet cloud carries his name. However, his assumption that short-period comets are descendants of long-period ones did not fare as well.
