Scientists Discuss: Interstellar Media

Astronomer: A scientist who specializes in the study of celestial bodies, space, and the physical universe.

Atom: The fundamental unit of chemical elements, composed of dense nuclei containing positively charged protons and neutral neutrons, with clouds of negatively charged electrons orbiting around the nucleus.

Bond: (In chemistry) a type of attachment between atoms or groups of atoms in a molecule, formed by the attractive forces of the atoms involved. When atoms combine, they function as a single unit, and energy in the form of heat or other radiation is required to separate them.

Celestial Bodies: Objects associated with the sky or the universe.

Heavenly Objects: Naturally occurring, substantial entities in space, such as comets, asteroids, planets, moons, stars, and galaxies.

Density: A measure of how compact an object is, calculated by dividing its mass by its volume.

I’ll Eject It: The act of forcefully removing or discarding something from its location, container, or housing.

Galaxy: A collection of stars, usually accompanied by invisible dark matter, all held together by gravity. Massive galaxies like the Milky Way can contain over 100 billion stars, while smaller galaxies may have only a few thousand. Some galaxies also contain gas and dust that facilitate the formation of new stars.

Helium: An inert gas and the lightest member of the Noble Gas family, which can solidify at -272 degrees Celsius (-458 degrees Fahrenheit).

Hydrogen: The lightest element in the universe, existing as a colorless and odorless gas that is highly flammable. It is a vital component of many fuels, fats, and chemicals that constitute living tissue, made up of a single proton as its nucleus and a single electron in its orbitals.

Infrared: A type of electromagnetic radiation that is not visible to the human eye, with longer wavelengths than visible light. The term means “below red” in Latin, and infrared waves can capture the thermal signature of an object or environment, along with other invisible wavelengths such as x-rays, radio waves, and microwaves.

Intergalactic: An adjective referring to the space between galaxies.

Interstellar: Relating to the space between stars.

Mass: A measure of the amount of matter in an object, indicating its resistance to acceleration.

Object: Any entity that occupies space and possesses mass, having the property known as “weight.”

Molecule: A neutral group of atoms representing the smallest unit of a compound, which can consist of the same type of atoms or different ones. For instance, oxygen in the air consists of two oxygen atoms (O₂), while water is formed from two hydrogen atoms and one oxygen atom (H₂O).

Oxygen: A gas making up about 21% of the Earth’s atmosphere, essential for the growth and metabolism of animals and many microorganisms.

Particle: A small quantity or portion of matter.

Radiation: One of the three primary methods of energy transfer in physics (the others being conduction and convection). Radiation involves the transfer of energy through electromagnetic waves without requiring a medium, allowing energy to travel through empty space.

Stars: The fundamental components that make up galaxies, formed when gravity compresses a cloud of gas. When the temperature is sufficient, stars emit light and other forms of electromagnetic radiation, with the Sun being the nearest star to Earth.

Telescope: An optical instrument that collects light to magnify distant objects, typically utilizing lenses and mirrors. Some telescopes also detect radio emissions through antennas, encompassing a broader part of the electromagnetic spectrum.

Universe: The entirety of existence within space and time, which has been expanding since its emergence during the Big Bang approximately 13.8 billion years ago.

Vacuum: A space with very low or no matter. Laboratories and manufacturing facilities may utilize vacuum technology to create vacuum chambers by removing air.

Visible Light: A type of electromagnetic radiation with wavelengths ranging from 380 nanometers (violet) to 740 nanometers (red), shorter than infrared but longer than ultraviolet, x-rays, and gamma rays.

Voyager: A pair of NASA missions aimed at exploring Jupiter, Saturn, and their rings. Voyager 2, launched on August 20, 1977, was sent 16 days after Voyager 1 and is notable for having left the solar system and entered deep space.