Voyager 1 is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and interstellar space beyond the Sun's heliosphere. Launched 16 days after its twin Voyager 2, Voyager 1 has been operating for 45 years and 10 days as of September 16, 2022 UTC [refresh] and still communicates with the Deep Space Network to receive routine commands and to transmit data to Earth. Real-time distance and velocity data is provided by NASA and JPL. At a distance of 157.58 AU from Earth as of September 12, 2022, it is the most distant humanmade object from Earth.
The heliosphere is the magnetosphere, astrosphere and outermost atmospheric layer of the Sun. It takes the shape of a vast, 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 first use of the word in scientific literature in 1967. The scientific study of the heliosphere is heliophysics, which includes space weather and space climate.
The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move. The IPM stops at the heliopause, outside of which the interstellar medium begins. Before 1950, interplanetary space was widely considered to either be an empty vacuum, or consisting of "aether".
The Committee on Space Research (COSPAR) was established on October 3, 1958 by the International Council for Scientific Unions (ICSU). Among COSPAR's objectives are the promotion of scientific research in space on an international level, with emphasis on the free exchange of results, information, and opinions, and providing a forum, open to all scientists, for the discussion of problems that may affect space research. These objectives are achieved through the organization of symposia, publication, and other means. COSPAR has created a number of research programmes on different topics, a few in cooperation with other scientific Unions. The long-term project COSPAR international reference atmosphere started in 1960; since then it has produced several editions of the high-atmosphere code CIRA. The code "IRI" of the URSI-COSPAR working group on the International Reference Ionosphere was first edited in 1978 and is yearly updated.
Solar physics is the branch of astrophysics that specializes in the study of the Sun. It deals with detailed measurements that are possible only for our closest star. It intersects with many disciplines of pure physics, astrophysics, and computer science, including fluid dynamics, plasma physics including magnetohydrodynamics, seismology, particle physics, atomic physics, nuclear physics, stellar evolution, space physics, spectroscopy, radiative transfer, applied optics, signal processing, computer vision, computational physics, stellar physics and solar astronomy.
The following outline is provided as an overview of and topical guide to astronomy:
Interstellar Boundary Explorer is a NASA satellite in Earth orbit that uses energetic neutral atoms (ENAs) to image the interaction region between the Solar System and interstellar space. The mission is part of NASA's Small Explorer program and was launched with a Pegasus-XL launch vehicle on 19 October 2008.
Space physics, also known as solar-terrestrial physics or space-plasma physics, is the study of plasmas as they occur naturally in the Earth's upper atmosphere (aeronomy) and within the Solar System. As such, it encompasses a far-ranging number of topics, such as heliophysics which includes the solar physics of the Sun, the solar wind, planetary magnetospheres and ionospheres, auroras, cosmic rays, and synchrotron radiation. Space physics is a fundamental part of the study of space weather and has important implications in not only to understanding the universe, but also for practical everyday life, including the operations of communications and weather satellites.
Heliophysics is the physics of the Sun and its connection with the Solar System. NASA defines heliophysics as "(1) the comprehensive new term for the science of the Sun - Solar System Connection, (2) the exploration, discovery, and understanding of Earth's space environment, and (3) the system science that unites all of the linked phenomena in the region of the cosmos influenced by a star like our Sun."
Energetic Neutral Atom (ENA) imaging, often described as "seeing with atoms", is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere.
The Heliophysics Science Division of the Goddard Space Flight Center (NASA) conducts research on the Sun, its extended Solar System environment, and interactions of Earth, other planets, small bodies, and interstellar gas with the heliosphere. Division research also encompasses geospace—Earth's uppermost atmosphere, the ionosphere, and the magnetosphere—and the changing environmental conditions throughout the coupled heliosphere.
NASA Heliophysics is an aspect of NASA science that enables understanding the Sun, heliosphere, and planetary environments as a single connected system. In addition to solar processes, this domain of study includes the interaction of solar plasma and solar radiation with Earth, the other planets, and the galaxy. By analyzing the connections between the Sun, solar wind, and planetary space environments, the fundamental physical processes that occur throughout the universe are uncovered. Understanding the connections between the Sun and its planets will allow for predicting the impacts of solar interaction on humans, technological systems, and even the presence of life itself. This is also the stated goal of Science Mission Directorate's Heliophysics Research.
David John McComas is an American space plasma physicist, Vice President for Princeton Plasma Physics Laboratory, and Professor of Astrophysical Sciences and leads the Space Physics at Princeton Group at Princeton University. He had been Assistant Vice President for Space Science and Engineering at the Southwest Research Institute, Adjoint Professor of Physics at the University of Texas at San Antonio (UTSA), and was the founding director of the Center for Space Science and Exploration at Los Alamos National Laboratory. He is noted for his extensive accomplishments in experimental space plasma physics, including leading instruments and missions to study the heliosphere and solar wind: IMAP, IBEX, TWINS, Ulysses/SWOOPS, ACE/SWEPAM, and Parker Solar Probe. He received the 2014 COSPAR Space Science Award and the NASA Exceptional Public Service Medal.
Barbara June Thompson is an American solar physicist. She is a scientist at Goddard Space Flight Center where she researches coronal mass ejections and the dynamics of coronal structures. Thompson was the project scientist for NASA's Solar Dynamics Observatory mission through development and early flight.
In solar physics, heliospheric pickup ions are created when neutral particles inside the heliosphere are ionized by either solar ultraviolet radiation, charge exchange with solar wind protons or electron impact ionization. Pickup ions are generally characterized by their single charge state, a typical velocity that ranges between 0 km/s and twice the solar wind velocity (~800 km/s), a composition that reflects their neutral seed population and their spatial distribution in the heliosphere. The neutral seed population of these ions can either be of interstellar origin or of lunar-, cometary, or inner-source origin. Just after the ionization, the singly charged ions are picked up by the magnetized solar wind plasma and develop strong anisotropic and toroidal velocity distribution functions, which gradually transform into a more isotropic state. After their creation, pickup ions move with the solar wind radially outwards from the Sun.
The Interstellar Mapping and Acceleration Probe(IMAP) is a heliophysics mission that will simultaneously investigate two important and coupled science topics in the heliosphere: the acceleration of energetic particles and interaction of the solar wind with the local interstellar medium. These science topics are coupled because particles accelerated in the inner heliosphere play crucial roles in the outer heliospheric interaction. In 2018, NASA selected a team led by David J. McComas of Princeton University to implement the mission, which is currently planned to launch in February 2025. IMAP will be a Sun-tracking spin-stabilized satellite in orbit about the Sun–Earth L1 Lagrange point with a science payload of ten instruments. IMAP will also continuously broadcast real-time in-situ data that can be used for space weather prediction.
NASA's Solar Terrestrial Probes program (STP) is a series of missions focused on study the Sun-Earth system. It is part of NASA's Heliophysics Science Division within the Science Mission Directorate.
Space climate is the long-term variation in solar activity within the heliosphere, including the solar wind, the Interplanetary magnetic field (IMF), and their effects in the near-Earth environment, including the magnetosphere of Earth and the ionosphere, the upper and lower atmosphere, climate, and other related systems. The scientific study of space climate is an interdisciplinary field of space physics, solar physics, heliophysics, and geophysics. It is thus conceptually related to terrestrial climatology, and its effects on the atmosphere of Earth are considered in climate science.
Eckart Marsch is a German theoretical physicist, who worked from 1980 to 2012 at the originally named Max Planck Institute for Aeronomy, from 2004 on named Max Planck Institute for Solar System Research (MPS) in Katlenburg-Lindau on the physics of the solar wind, solar corona and space plasmas and taught at the University of Göttingen.
Natchimuthuk Gopalswamy is an American solar physicist. He is currently a staff scientist at the Heliophysics Division of NASA’s Goddard Space Flight Center.
