Intergalactic travel is hypothetical crewed or uncrewed travel between galaxies. Due to the enormous distances between our own galaxy the Milky Way and even its closest neighbors --tens of thousands to millions of light-years-- any such venture would be far more technologically demanding than even interstellar travel. Intergalactic distances are roughly a hundred-thousandfold (five orders of magnitude) greater than their interstellar counterparts.

The technology required to travel between galaxies is far beyond humanity's present capabilities, and currently only the subject of speculation, hypothesis, and science fiction.

However, theoretically speaking, there is nothing to conclusively indicate that intergalactic travel is impossible. There are several hypothesized methods of carrying out such a journey, and to date several academics have studied intergalactic travel in a serious manner

Due to the distances involved, any serious attempt to travel between galaxies would require methods of propulsion far beyond what is currently thought possible in order to bring a large craft close to the speed of light.

According to the current understanding of physics, an object within space-time cannot exceed the speed of light, which means an attempt to travel to any other galaxy would be a journey of millions of earth years via conventional flight.

Manned travel at a speed not close to the speed of light, would require either that we overcome our own mortality with technologies like radical life extension or traveling with a generation ship. If traveling at a speed closer to the speed of light, time dilation would allow intergalactic travel in a timespan of decades of on-ship time.

Additional constraints include the variety of unknowns regarding the durability of a spaceship for such complex travel. Fluctuating temperatures as in the warm-hot intergalactic medium could potentially disintegrate future spacecraft if not properly shielded.

These challenges also mean a return trip would be very difficult, and the time for a return trip might possibly exceed the species lifetime of humans on Earth. Therefore, all future studies on the risks and feasibility of intergalactic travel would have to include a wide range of simulations to increase chances of a successful payload.

The cosmos is the Universe. Using the word cosmos rather than the word universe implies viewing the universe as a complex and orderly system or entity; the opposite of chaos. The cosmos, and our understanding of the reasons for its existence and significance, are studied in cosmology a very broad discipline covering any scientific, religious, or philosophical contemplation of the cosmos and its nature, or reasons for existing. Religious and philosophical approaches may include in their concepts of the cosmos various spiritual entities or other matters deemed to exist outside our physical universe.

Observations with the Hubble Space Telescope and other observatories showed that the universe is expanding at an ever-increasing rate, implying that some day - in the very distant future - anyone looking at the night sky would see only our Galaxy and its stars. The billions of other galaxies will have receded beyond detection by these future observers. The origin of the force that is pushing the universe apart is a mystery, and astronomers refer to it simply as "dark energy". This new, unknown component, which comprises ~68% of the matter-energy content of the universe, will determine the ultimate fate of all. Determining the nature of dark energy, its possible history over cosmic time, is perhaps the most important quest of astronomy for the next decade and lies at the intersection of cosmology, astrophysics, and fundamental physics.

NASA Planetary Science aims to answer the many questions of the solar system from how life began to how the solar system is evolving. The solar system is a place of beauty and mystery, incredible diversity, extreme environments, and continuous change. The solar system is also a natural laboratory, on a grand scale, within which we seek to unravel the mysteries of the universe and our place within it.

How did life begin and evolve on Earth, and has it evolved elsewhere in the Solar System?
Microbial life forms have been discovered on Earth that can survive and even thrive at extremes of high and low temperature and pressure, and in conditions of acidity, salinity, alkalinity, and concentrations of heavy metals that would have been regarded as lethal just a few years ago.

How did the solar system evolve to its current diverse state?
Many of the other solar systems have massive Jupiter like planets close to their sun, closer even than Mercury. Many scientists now believe that these gas giants could not have formed there. Rather, they must have began out where our Jupiter is, and moved inwards, scattering the smaller planets with their powerful gravity as they went.

How did the sun's family of planets and minor bodies originate?
For the first time in human history we know of planets around other stars and many of those other planetary systems look quite different from our own. Many have a planet like Jupiter, or even bigger, nearest to the sun. If we are to understand why this is the case, and how likely it is that there are Earth-like planets elsewhere, we need to better understand how planets form.

What are the characteristics of the Solar System that lead to the origins of life?
The possibility of finding life elsewhere is for many people the most compelling reason for humankind to explore beyond the Earth. We believe that liquid water and carbon are required for life to arise and thrive, as well as a source of energy. Many places in the solar system provide these, at least for a time; not only planets, but also some moons and even certain comets. But for life to arise we presume that a hospitable environment must be more than just transient.

The Science Mission Directorate Heliophysics Division studies the nature of the Sun, and how it influences the very nature of space  and, in turn, the atmospheres of planets and the technology that exists there. Space is not, as is often believed, completely empty; instead, we live in the extended atmosphere of an active star. Our Sun sends out a steady outpouring of particles and energy -- the solar wind  as well as a constantly writhing magnetic system. This extensive, dynamic solar atmosphere surrounds the Sun, Earth, the planets, and extends far out into the solar system.

Studying this system not only helps us understand fundamental information about how the universe works, but also helps protect our technology and astronauts in space. NASA seeks knowledge of near-Earth space, because -- when extreme -- space weather can interfere with our communications, satellites and power grids. The study of the Sun and space can also teach us more about how stars contribute to the habitability of planets throughout the universe.

Mapping out this interconnected system requires a holistic study of the Suns influence on space, Earth and other planets. NASA has a fleet of spacecraft strategically placed throughout our heliosphere -- from Parker Solar Probe at the Sun observing the very start of the solar wind, to satellites around Earth, to the farthest human-made object, Voyager, which is sending back observations on interstellar space. Each mission is positioned at a critical, well-thought out vantage point to observe and understand the flow of energy and particles throughout the solar system -- all helping us untangle the effects of the star we live with.

NASA's Earth Science Division (ESD) missions help us to understand our planet's interconnected systems, from a global scale down to minute processes. Working in concert with a satellite network of international partners, ESD can measure precipitation around the world, and it can employ its own constellation of small satellites to look into the eye of a hurricane. ESD technology can track dust storms across continents and mosquito habitats across cities.

ESD delivers the technology, expertise and global observations that help us to map the myriad connections between our planet's vital processes and the effects of ongoing natural and human-caused changes.

Using observations from satellites, instruments on the International Space Station, airplanes, balloons, ships and on land, ESD researchers collect data about the science of our planet's atmospheric motion and composition; land cover, land use and vegetation; ocean currents, temperatures and upper-ocean life; and ice on land and sea. These data sets, which cover even the most remote areas of Earth, are freely and openly available to anyone.

The four program elements of ESD design the science and technology, launch airborne and space missions, analyze the data and observations, and develop ways to put the information to use for societal benefit. ESD also sponsors research and extends science and technology education to learners of all ages, inspiring the next generation of explorers.

More than collecting the data, however, ESD works with government and commercial partners in the U.S. and internationally to put that unique information to work as we explore our home planet, improve lives and safeguard the future for people all over the world. Earth science research also helps advance space exploration by helping scientists recognize the basic markers for life across the universe.