Kuiper Belt in the context of "Makemake"

The heliosphere is the magnetosphere, astrosphere, and outermost atmospheric layer of the Sun. It takes the shape of a vast, tailed bubble-like region of space. In plasma physics terms, it is the cavity formed by the Sun in the surrounding interstellar medium. The "bubble" of the heliosphere is continuously "inflated" by plasma originating from the Sun, known as the solar wind. Outside the heliosphere, this solar plasma gives way to the interstellar plasma permeating the Milky Way. As part of the interplanetary magnetic field, the heliosphere shields the Solar System from significant amounts of cosmic ionizing radiation; uncharged gamma rays are, however, not affected. Its name was likely coined by Alexander J. Dessler, who is credited with the first use of the word in the scientific literature in 1967. The scientific study of the heliosphere is heliophysics, which includes space weather and space climate.

Flowing unimpeded through the Solar System for billions of kilometers, the solar wind extends far beyond even the region of Pluto until it encounters the "termination shock", where its motion slows abruptly due to the outside pressure of the interstellar medium. The "heliosheath" is a broad transitional region between the termination shock and the heliosphere's outmost edge, the "heliopause". The overall shape of the heliosphere resembles that of a comet, being roughly spherical on one side to around 100 astronomical units (AU), and on the other side being tail shaped, known as the "heliotail", trailing for several thousands of AUs.

In astronomy, the Hills cloud (also called the inner Oort cloud and inner cloud) is a theoretical vast circumstellar disc, interior to the Oort cloud, whose outer border would be located at around 20,000 to 30,000 astronomical units (AU) from the Sun, and whose inner border, less well defined, is hypothetically located at 250–1500 AU, well beyond planetary and Kuiper Belt object orbits—but distances might be much greater. If it exists, the Hills cloud likely contains roughly 5 times as many comets as the Oort cloud.

Modified Newtonian dynamics (MOND) is a theory that proposes a modification of Newton's laws to account for observed properties of galaxies. Modifying Newton's law of gravity results in modified gravity, while modifying Newton's second law results in modified inertia. The latter has received little attention compared to the modified gravity version. Its primary motivation is to explain galaxy rotation curves without invoking dark matter, and is one of the most well-known theories of this class.

MOND was developed in 1982 and presented in 1983 by Israeli physicist Mordehai Milgrom. Milgrom noted that galaxy rotation curve data, which seemed to show that galaxies contain more matter than is observed, could also be explained if the gravitational force experienced by a star in the outer regions of a galaxy decays more slowly than predicted by Newton's law of gravity. MOND modifies Newton's laws for extremely small accelerations which are common in galaxies and galaxy clusters. This provides a good fit to galaxy rotation curve data while leaving the dynamics of the Solar System with its strong gravitational field intact. However, the theory predicts that the gravitational field of the galaxy could influence the orbits of Kuiper Belt objects through the external field effect, which is unique to MOND.

Jane X. Luu (Vietnamese: Lưu Lệ Hằng; born July 1963) is a Vietnamese-American astronomer and defense systems engineer. She was awarded the Kavli Prize (shared with David C. Jewitt and Michael Brown) for 2012 "for discovering and characterizing the Kuiper Belt and its largest members, work that led to a major advance in the understanding of the history of our planetary system".

Luu immigrated to the United States as a refugee in 1975, when the South Vietnamese government during the fall of Saigone. She and her family lived in refugee camps and motels before they settled in Kentucky, where she had relatives. She graduated from high school as valedictorian and then earned a scholarship to Stanford University, receiving her bachelor's degree in physics in 1984. Working at the Jet Propulsion Laboratory at NASA after college inspired her to study astronomy.