The Final Images We Will Ever See of Pluto and Arrokoth
The New Horizons space probe, launched in 2006, provided the first detailed images of Pluto and its moons in 2015, after a nine-year journey. Pluto, a tiny dwarf planet in the Kuiper Belt, was revealed to have an unusual relationship with its large moon Charon, with both objects tidally locked and orbiting a point in space. Pluto's surface features a giant heart-shaped ice plain called Sputnik Planitia, composed mainly of nitrogen ice, which flows like glaciers. The surface also has dark areas of tholins, tar-like organic compounds, and evidence of cryovolcanoes. Interestingly, some tholins from Pluto are transferred to Charon, creating a red polar cap. Pluto also possesses a thin, hazy atmosphere that varies in density. After Pluto, New Horizons visited Arrokoth in 2019, the most distant object ever explored. Arrokoth is a reddish, two-lobed object with few craters, suggesting it's a time capsule from the early solar system, likely formed by a slow collision or gentle merging. New Horizons continues its journey, with plans to operate as a unique observatory in the outer solar system.
Key Vocabulary
The process where a solid substance changes directly into a gas without first becoming a liquid. This occurs when the temperature and pressure conditions are such that the solid bypasses the liquid phase.
Examples:
- Dry ice is known for sublimating at room temperature, producing a smoky effect.
- On very cold planets, certain ices might be seen sublimating directly into the thin atmosphere.
- The artist used a special ink that would sublimate when heated, transferring the design onto fabric.
A compound containing one oxygen atom combined with another element, typically carbon. In the context of planetary atmospheres, it refers to a gaseous compound like carbon monoxide.
Examples:
- Carbon monoxide is a colorless, odorless gas that can be dangerous in enclosed spaces.
- Scientists detected traces of nitrogen monoxide in the upper atmosphere of the gas giant.
- The incomplete combustion of fuel can lead to the production of carbon monoxide.
To look with eyes partly closed, often to see more clearly or to protect the eyes from bright light. When applied to a telescope, it refers to its ability to focus its optics to discern faint or distant objects.
Examples:
- She squinted at the small print on the contract, trying to decipher the terms.
- The photographer squinted through the viewfinder, adjusting the focus for a sharper image.
- He squinted against the glare of the morning sun as he stepped outside.
Having an irregular shape or consistency, characterized by small, solid masses or bumps. In the context of celestial bodies, it describes a surface that is not smooth but has noticeable protuberances.
Examples:
- The clay felt lumpy in her hands as she tried to mold it into a smooth pot.
- After stirring the batter, he noticed it was still a bit lumpy, indicating not all the flour had mixed in.
- The old mattress had become lumpy and uncomfortable over the years.
A state of minimal activity and metabolic depression in endotherms, characterized by lower body temperature, slower breathing, and lower metabolic rate. In the context of spacecraft, it refers to a period of reduced activity to conserve power and minimize wear.
Examples:
- Bears enter a state of hibernation during the winter months to survive the cold and scarcity of food.
- The spacecraft was put into hibernation mode for its long journey across the solar system.
- During its hibernation, the animal's heart rate dropped significantly.
The dark shape and outline of someone or something visible against a lighter background, especially in a shadow. When observing distant objects, it refers to seeing their outline against a bright source like a star.
Examples:
- The tall trees formed a stark silhouette against the setting sun.
- She could only make out his silhouette in the dim light of the hallway.
- The mountain range created a dramatic silhouette on the horizon.
Hard but easily broken or shattered. When describing materials like ice, it means they are rigid and prone to fracturing under stress.
Examples:
- The old plastic became brittle and cracked easily after years in the sun.
- Sugar glass is a brittle material often used in movie stunts because it shatters safely.
- The dry leaves were so brittle that they crumbled to dust when touched.
Relating to gravity, the force of attraction that exists between any two masses, or the phenomenon in which objects are attracted to each other due to their mass. It describes effects or phenomena caused by this force.
Examples:
- The moon's gravitational pull is responsible for the Earth's tides.
- Scientists are studying the gravitational waves emanating from distant cosmic events.
- A strong gravitational field can bend light, creating a lensing effect.
The transfer of heat by the movement of a fluid (liquid or gas) or, in the case of planetary bodies, by the movement of solid material that behaves like a fluid over long timescales. This process often forms cells or patterns as warmer, less dense material rises and cooler, denser material sinks.
Examples:
- Convection currents in the ocean help distribute heat around the globe.
- The boiling water in the pot showed clear signs of convection, with bubbles rising to the surface.
- Heat from the Earth's core is transferred to the mantle through convection.
Tending to remind one of something. It describes a quality or appearance that brings to mind something else due to a similarity.
Examples:
- The old house had a decor reminiscent of the 1970s, with vibrant colors and bold patterns.
- Her laugh was strangely reminiscent of her grandmother's, warm and full of joy.
- The painting's style was reminiscent of the Impressionist masters, with its soft brushstrokes and play of light.
With a clear intention or aim; deliberately. It implies that an action is done with a specific goal in mind, not by accident.
Examples:
- She purposefully left the door ajar, hoping he would notice and come in.
- The architect purposefully designed the building with large windows to maximize natural light.
- He spoke slowly and purposefully, ensuring every word was understood.
Situated or occurring between the stars. It refers to the space or matter found in the vast regions between star systems within a galaxy.
Examples:
- The Voyager probes are now traveling through interstellar space, beyond the influence of our sun.
- Scientists study interstellar dust clouds to understand the conditions for star formation.
- Some theories suggest that life might be transported between star systems via interstellar objects.
Scattered small drops or particles over a surface. In the context of planetary surfaces, it refers to material dispersed across an area, giving the appearance of being lightly scattered.
Examples:
- She sprinkled cheese over the pasta before serving it.
- The baker sprinkled powdered sugar on top of the freshly baked pastries.
- Tiny lights were sprinkled across the night sky, resembling distant stars.
A mass of snow, ice, and rocks rapidly sliding down a mountainside. In a broader sense, it can refer to a sudden, overwhelming quantity of something that descends or falls.
Examples:
- The skiers were warned about the risk of avalanches after a heavy snowfall.
- A small rock avalanche blocked the mountain road, delaying travelers.
- He felt an avalanche of emotions as he received the surprising news.
Pertaining to the sky or heavens, or to the divine. In astronomy, it refers to objects or phenomena observed in the sky or outer space.
Examples:
- Ancient cultures often attributed divine powers to celestial bodies like the sun and moon.
- The observatory was built to study distant celestial phenomena.
- Navigators once relied on celestial navigation, using the stars to find their way.
Composed of or involving two things. In astronomy, a binary system typically refers to two celestial objects, such as stars or asteroids, that are gravitationally bound and orbit around a common center of mass.
Examples:
- Many star systems are in fact binary, with two stars orbiting each other.
- The computer operates using a binary code, represented by ones and zeros.
- Researchers discovered a binary asteroid system, where two asteroids orbit each other.
Relating to astronomy, the scientific study of celestial objects and phenomena. It can also mean extremely large or vast, often used to describe numbers or distances.
Examples:
- The costs associated with launching a new space telescope are astronomical.
- Astronomical observations have greatly expanded our understanding of the universe.
- The distance to the nearest galaxy is truly astronomical, requiring light-years to measure.
To change from a gas or vapor to a liquid, or from a gas/liquid to a solid. In atmospheric science, it refers to gases cooling and forming liquid droplets or solid particles.
Examples:
- As the warm, moist air rises, it cools and condenses, forming clouds.
- Water vapor condenses on cold surfaces, creating dew or frost.
- When the steam condenses, it turns back into water.
A cavity in the ground, especially in limestone bedrock, caused by water erosion and providing a route for surface water to disappear underground. On celestial bodies, it refers to a depression formed by the collapse of a surface layer into an underlying cavity, often due to the escape of volatile substances.
Examples:
- Heavy rains caused a massive sinkhole to open up in the middle of the road.
- Explorers discovered an ancient Mayan temple hidden within a large sinkhole.
- The sudden appearance of a sinkhole prompted an investigation into the underground water system.
The region of a planetary body between the crust and the core. It is typically composed of solid rock that can flow slowly over geological timescales due to high temperatures and pressures.
Examples:
- The Earth's mantle is responsible for the movement of tectonic plates.
- Scientists study seismic waves to understand the composition and structure of the planet's mantle.
- Volcanic eruptions often bring material from deep within the mantle to the surface.