Space Physics Definitions Flashcards
(34 cards)
What is Axis?
An invisible line around which an object rotates, or spins.
What is Hemisphere?
The two equal halves created when the Earth is split in horizontally – the northern hemisphere and the southern hemisphere.
What is Orbit?
a repeating circular path around another body.
What is Orbital period?
The time taken for an object to complete one orbit.
What is Periodic?
A phenomenon is one that occurs at regular intervals.
What is Planet?
A sphere of rock or gas orbiting a star with a gravitational field strong enough to pull in all nearby objects.
What is Waxing?
This term describes when the illuminated proportion of the Moon’s visible surface is increasing.
What is Waning?
This term describes when the illuminated proportion of the Moon’s visible surface is decreasing.
What is Accretion?
the process of growth or increase by the gradual accumulation of matter.
What is Asteroid?
A small rocky object in the asteroid belt between Mars and Jupiter, which orbits the sun.
What is Artificial Satellite?
Objects sent into a planet’s orbit by mankind (such as the International Space Station).
What is Comet?
An object made of dust and ice that orbits the Sun in a highly elliptical orbit, which often reaches beyond the solar system.
What is Elliptical?
The oval-shaped path with which objects orbit the sun. Some objects, such as comets, have a more elliptical orbit than others.
What is Minor Planet?
A mass that orbits the sun but does not have a gravitational field strong enough to pull in all nearby objects.
What is Natural Satellite?
Naturally occurring bodies that orbit a planet (such as a moon).
What is Solar System?
The gravitationally bound systems of a star and the objects that orbit it. Solar systems orbit around their galaxies just as planets orbit around their suns.
What is The Sun?
The star at the centre of our solar system.
What is Electromagnetic spectrum?
The range of wavelengths or frequencies over which electromagnetic radiation extends.
What is Infrared radiation?
Radiation extending from the red, longer wavelengths of the visible-light range to the microwave range. It is invisible to the eye and felt as heat.
What is Nuclear fusion?
The process of making a single heavy nucleus (part of an atom) from two lighter nuclei.
What is Star?
A ball of gas, mostly hydrogen and helium, held together by gravity.
What is Ultraviolet radiation?
Radiation of a wavelength which is shorter than visible light but longer than X-rays. It is invisible to the eye and turns skin darker.
What is Visible radiation?
Radiation of wavelengths between ultraviolet and infrared, which is visible to the human eye.
What is Astronomical distance?
The distance from one celestial body to another, measured in light-years (9.5 × 10¹⁵ m).
