The age of a sample expressed in years.

The collapsed core of a massive star resulting from a supernova explosion.

Changes in an orbiting body's axis of rotation or orbit due to gravitational tugs by celestial bodies.

The thin layer of gases surrounding planets and stars held by gravity.

The process by which an unstable atom loses particles from its nucleus.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

A scientist who studies the origin and dynamics of the universe.

Single-celled organisms with calcium carbonate shells that live in marine and freshwater environments.

The atom that undergoes radioactive decay in a nuclear reaction.

The collapsed core of a massive star resulting from a supernova explosion.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

An instrument used to view distant objects using lenses and/or mirrors.

The product atom from the radioactive decay of a parent atom.

The point in Earth's orbit closest to the Sun.

An intense burst of radiation from the release of magnetic energy associated with sunspots.

The time it takes for half of a radioactive substance to decay.

A state of matter consisting of ionized atoms and free electrons.

The outer planets of the solar system, including Jupiter, Saturn, Uranus, and Neptune, composed mostly of hydrogen, helium, and methane.

A unit of measurement used in astronomy to describe large distances.

The long-term pattern of weather conditions in a region.

The ratio of the distance between the foci and the length of the major axis of an ellipse.

A large, cold cloud of molecular hydrogen and helium, with other gases, in space.

An intense burst of radiation from the release of magnetic energy associated with sunspots.

The average climatic conditions over Earth's surface determined by a large number of spatially distributed observations.

The part of the electromagnetic spectrum detectable by human eyes.

A star formed when the temperature in the center of a cloud reaches 15 million K, initiating stellar fusion.

The climatic conditions in the geologic past reconstructed from direct or indirect data sources.

Bright emissions caused by charged particles entering Earth's upper atmosphere.

The wavelength of electromagnetic radiation with the most energy emitted by an object.

A scientist who studies the universe.

A large sheet of ice, often referred to as a glacier, that covers a continent.

Interglacial Interval

A period of warmer than glacial interval climate with receding glaciers.

A dark, cooler area on the surface of the Sun.

Atoms of a given element that differ in mass due to different numbers of neutrons in the nucleus.

The period from the mid-1300s to the mid-1800s when global temperatures were at their coldest since the beginning of the Holocene.

Electromagnetic radiation with wavelengths between about 0.7 to 1000 μm.

The collapsed core of a massive star resulting from a supernova explosion.

Continental Ice Sheet

A large sheet of ice, often referred to as a glacier, that covers a continent.

The apparent change of wavelength occurring when an object is moving toward or away from an observer.

An instrument used to observe radio waves.

The study of waves generated within the Sun that reveal its internal structure.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

Any feature or data set that indirectly measures climatic factors.

The long-term pattern of weather conditions in a region.

The point in Earth's orbit closest to the Sun.

Atoms of a given element that differ in mass due to different numbers of neutrons in the nucleus.

The solar radiation received in Earth's atmosphere or at its surface.

The apparent change of wavelength occurring when an object is moving toward or away from an observer.

Single-celled organisms with calcium carbonate shells that live in marine and freshwater environments.

The long-term pattern of weather conditions in a region.

A planet similar in size, composition, and density to Earth, including Mercury, Venus, Earth, or Mars.

Windblown silt deposits in mid-latitudes during glacial and postglacial times.

The period from the mid-1300s to the mid-1800s when global temperatures were at their coldest since the beginning of the Holocene.

Cyclical changes in the geometric relationship between Earth and the Sun causing variations in solar radiation received at Earth's surface.

The ratio of the distance between the foci and the length of the major axis of an ellipse.

The climatic conditions in the geologic past reconstructed from direct or indirect data sources.

The tilt of Earth's rotation axis measured from the perpendicular to the plane of Earth's orbit.

The thin layer of gases surrounding planets and stars held by gravity.

A small body formed from the solar nebula that eventually grew into protoplanets.

Changes in an orbiting body's axis of rotation or orbit due to gravitational tugs by celestial bodies.

A relatively large clump of material formed in the early stages of solar system formation, which became the seed of the planets we see today.

The visible surface of the Sun.

The science that studies the interaction of light with matter.

Factors describing the orientation and movement of an orbiting body or the shape of its orbital path.

An intense burst of radiation from the release of magnetic energy associated with sunspots.

The period from the mid-1300s to the mid-1800s when global temperatures were at their coldest since the beginning of the Holocene.

A unit of measurement used in astronomy to describe large distances.

The solar radiation received in Earth's atmosphere or at its surface.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

The process by which an unstable atom loses particles from its nucleus.

The law stating that the amount of radiation passing through an area is inversely proportional to the square of the distance from the energy source.

The study of waves generated within the Sun that reveal its internal structure.

An intense burst of radiation from the release of magnetic energy associated with sunspots.

A cloud of interstellar gas and dust, appearing as a fuzzy patch in the sky.

The point in Earth's orbit closest to the Sun.

The study of waves generated within the Sun that reveal its internal structure.

The core of a massive star after a supernova, exerting such strong gravity that not even light can escape.

The point in Earth's orbit farthest from the Sun.

The range of frequencies of electromagnetic radiation.

The period from the mid-1300s to the mid-1800s when global temperatures were at their coldest since the beginning of the Holocene.

The slow rotation of Earth's axis around a cone due to gravitational tugs by celestial bodies.

A relatively large clump of material formed in the early stages of solar system formation, which became the seed of the planets we see today.

The time it takes for half of a radioactive substance to decay.

The scientific idea that our solar system formed from a giant, rotating cloud of gas and dust.

Rotation of the major axis of Earth's elliptical orbit about the Sun.

The solar radiation received in Earth's atmosphere or at its surface.

Electromagnetic radiation with wavelengths between about 0.7 to 1000 μm.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

Cyclical changes in the geometric relationship between Earth and the Sun causing variations in solar radiation received at Earth's surface.

The process by which an unstable atom loses particles from its nucleus.

The ratio of the distance between the foci and the length of the major axis of an ellipse.

The solar radiation received in Earth's atmosphere or at its surface.

The Sun, planets, and other bodies that orbit the Sun.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

The solar radiation received in Earth's atmosphere or at its surface.

A large, round body that orbits the Sun.

The amount of matter in an object.

A scientist who studies the universe.

Bright emissions caused by charged particles entering Earth's upper atmosphere.

The period from the mid-1300s to the mid-1800s when global temperatures were at their coldest since the beginning of the Holocene.

A unit of measurement equal to the average distance between the Sun and Earth.

Rotation of the major axis of Earth's elliptical orbit about the Sun.

The range of frequencies of electromagnetic radiation.

A celestial object that emits its own light and is made up of gas held together by gravity.

The point in Earth's orbit farthest from the Sun.

A unit of measurement equal to the average distance between the Sun and Earth.

A large grouping of stars in space.

A celestial object that emits its own light and is made up of gas held together by gravity.

A small planetary body in orbit around the Sun, larger than a meteoroid but smaller than a planet.

An instrument used to observe radio waves.

A unit of measurement equal to the distance light travels in one year.