Diamond rain is thought to form within Uranus and Neptune, whose interiors can compress carbon atoms from methane into these falling crystals.

Diamonds have been made from substances such as peanut butter and carbon dioxide, though they can be created from any carbon-rich material under extreme pressure and temperature.

Despite being called 'ice giants,' Uranus and Neptune do not contain plentiful frozen water—the term refers to their abundance of elements heavier than hydrogen and helium.

How diamonds form in the deep earth

Deep within Earth's mantle, diamonds form from carbon-bearing fluids. The formation of these beautiful gemstones, the only direct samples we have of the mantle, helps scientists uncover how carbon functions deep inside our planet. Understanding this complex process aids in the exploration for new diamond deposits.

Some synthetic diamonds are purposely made with defects for new technologies

Grown in plasma-filled chambers or reactors where pressures reach 800,000 pounds per square inch, diamonds can develop properties like electrical conductivity and magnetic field sensitivity through exposure to elemental impurities or removal of some of their carbon atoms.

There may be 74,963 kinds of ice, resulting from water molecules rearranging themselves

The theoretical limit greatly expands the known types of ice, with type Iₕ being the most common on Earth and forming hexagonal crystals. The extreme environments of planets like Uranus and Neptune can create a variety of ice with unique structures and properties, as these conditions can reshape these crystals into new geometries.

A look at Uranus, our distant icy cousin

NASA provides a profile of the seventh planet from the sun and the third largest—Uranus. More than just a punchline, the planet is cold, windy, and utterly inhospitable. It's also a lovely blue-green, due to the large amounts of methane it contains, with faint rings and two dozen moons. Learn more about this not-so-gentle gas giant.

A diamond's color comes from impurities, defects, and unique formation processes

While most diamonds are transparent and sparkly, the presence of nitrogen and boron during formation can make them yellow, orange, or blue. Radiation can produce green diamonds, and structural deformities can introduce red hues.

Metallic hydrogen exists in Jupiter and Saturn due to high pressure and temperature

This state of hydrogen has metallic properties, including conductivity, which powers these planets' magnetic fields. First theorized in the 1930s, its existence was confirmed through indirect evidence before being created in a Harvard lab in 2017.

The new phenomenon of 15-minute lab-grown diamonds

In 2024, scientists developed a groundbreaking method to create diamonds at normal room temperature and pressure. This efficient and simple process contrasts with the traditional high-pressure, high-temperature method. While limitations still exist, such as minuscule sizes, this discovery moves us toward an exciting new era in diamond synthesis. Check out the article for further information about how diamonds are made.

While published images have suggested that Neptune is much bluer than Uranus, the two ice giants are a similarly pale shade of greenish-blue.

Jupiter’s size forced the creation of modified planetary formation models

Since solar winds remove gases from protoplanetary disks within millions of years of a star’s birth, models needed to provide a mechanism to jump-start Jupiter’s formation and growth. The solution involved incorporating pebbles of matter into the disk.

Research shows that cosmic rays may trigger the cascade of displaced electrons needed to produce lightning, which is also enabled by pointed ice crystals that create strong electric fields.

Synthetic diamonds may be used to cool microchips

The strong carbon bonds in diamonds efficiently carry vibrations, allowing them to conduct heat several times faster than copper, a metal commonly used in heat sinks. AI and high-performance computing have pushed researchers to investigate alternative materials for cooling solutions.

Since 1989, storms resembling Jupiter's Great Red Spot have been observed on Neptune, but darker and lasting no more than a few years.

A return to Uranus

There's been only one mission to Uranus before—Voyager 2 passed by the ice giant in 1986 before heading off into interstellar space. NASA's recent planned itinerary for space missions lists Uranus as the highest priority over the next decade. The seventh planet is 20 times as far from the sun as Earth, and researchers say its study will shed light on how the outer half of the Solar System formed.

Although no such planet exists in our solar system, the most common subtype of exoplanet in the galaxy is the sub-Neptune world, which is larger than Earth but smaller than the ice giants.

Extraterrestrial volcanoes spew material present during their formation

Unlike Earth's volcanoes that release lava, cryovolcanoes on distant moons erupt cold jets of water, ammonia, and other light gases present during the formation of their host planet. The movement of internal heat produced during formation is thought to drive icy plume movement.

Astronomers inferred Neptune's existence through mathematics while attempting to explain irregularities in Uranus' orbit, but Neptune had been directly observed 234 years earlier by Galileo.

Earth's magnetic field can trap high-energy charged particles produced by the sun and distant cosmic events in doughnut-shaped rings called Van Allen belts.

There may be over one trillion comets in the Kuiper Belt

Named after Gerard Kuiper, who theorized the existence of a band of icy objects beyond Neptune in 1951, direct evidence for its existence did not arrive until 1992, when the first trans-Neptunian object, besides Pluto and its moon Charon, was observed. Comets with periods of less than 200 years originate from this belt.

Reaching 2,400 kilometers per hour (1,500 miles per hour), Neptune's winds are the strongest in the solar system.

One of the hottest known exoplanets seems to snow an active ingredient of sunscreen, titanium dioxide—but only on the dark side of the planet.

Cloud formation requires water vapor and condensation nuclei to build from

The nuclei—particles like dust, salt, and smoke—act like jumpstarts that water molecules can start to accumulate onto to form clouds. Condensation nuclei are about 1/100th the size of cloud droplets, which are mostly water.

Some research suggests Jupiter formed near Uranus’ current orbit and migrated inward

Scientists from the University of Zurich and NCCR PlanetS proposed the mechanism after using computer modeling to replicate Jupiter’s formation to match its observed concentration of heavy elements. The work may help understand how Jupiter-like exoplanets exist near host stars.

The composition of comets earned them the nickname 'dirty snowballs'

The icy relics of the solar system are composed of rock, gravel, dust, and frozen molecules, such as carbon dioxide, carbon monoxide, methane, ammonia, and water. Once close to the sun, these compounds sublimate into gases, creating a fuzzy cloud that earned the comets another nickname in history: hairy stars.

The dynamo theory explains how planets generate their own magnetic fields

According to the theory, a large magnetic field generator, or dynamo, is created when liquid metal flows through the planet's outer core, producing electric currents that generate a magnetic field. Magnetization patterns in rocks on the surface of planets can serve as evidence for the presence of this internal structure at some point in the celestial object's past.

Hail forms in freezing temperatures thousands of feet above the ground

Even if surface temperatures are well above freezing during the summer, updrafts during thunderstorms can push raindrops high into the atmosphere, where they can freeze and form hail. Giant hailstones the size of softballs require updrafts of close to 100 mph.

Watch a visualization of the formation of the planets

The nebular hypothesis proposes that a swirling cloud of gas and dust coalesced into a dense center, forming a star amid nuclear fusion. Lighter elements were blown far from the star while heavier elements remained nearby, serving as primary materials for terrestrial and jovian planets, respectively.

Hypotheses on the origins of Earth's water, from comets and asteroids to magma oceans

Before Earth's atmosphere formed, any liquid water would have boiled off, preventing the accumulation of water early on to create today's oceans. Planetary scientists continue to debate whether this water was delivered later from comet or asteroid collisions or via reactions between iron oxide in Earth's molten surface and hydrogen gas from the planetary nebula.

A 37.41 carat, bicolor diamond likely formed from two distinct geological processes

Discovered in a Botswana mine, half the stone is clear, having formed from carbon being squeezed under extreme heat and pressure into a tight crystal structure. The pink half formed earlier and resulted from minor bending of the crystal during tectonic activity without causing it to brown or break.

As crystals form, their properties and the shapes they take on, including cubic, tetragonal, and hexagonal patterns, reflect the arrangement of their constituent atoms.

Several birthstones play key roles across modern technologies

Diamonds are used in drills and quantum computing, while peridot and zircon help in steelmaking and carbon capture. Rubies, sapphires, and alexandrite enable several varieties of lasers found in medicine and advanced optics. Garnets are found in water filtration systems and radiation detectors. Sapphires are used as substrates in semiconductors.

The conditions needed for cloud iridescence, or rainbow clouds

The relatively rare phenomenon occurs when sunlight scatters off tiny water droplets or ice crystals in thin, newly-forming or semi-transparent clouds, such as altocumulus, cirrocumulus, lenticular, and cirrus varieties. This effect is similar to what is seen in soap bubbles and mother-of-pearl shells and produces pastel-like colors.

James Webb telescope shows new views of Uranus

Following in the footsteps of the Neptune image released in 2022, NASA’s James Webb Space Telescope has taken a stunning image of the solar system’s other ice giant, the planet Uranus. The new image features dramatic rings as well as bright features in the planet’s atmosphere.

In 2025, astronomers confirmed that Neptune has auroras, which were observed at mid-latitudes because its magnetic field is tilted 47 degrees from its rotation axis.

Ice found in another star system for the first time

NASA's James Webb Space Telescope has discovered frozen water in a young star system. The ice is similar to that found in Kuiper Belt objects in our solar system, and provides insights into planetary formation processes.

As seen in the dark region of the Horsehead Nebula, clouds of space dust can block some forms of light from reaching telescopes, impairing observations and data collection.

Cosmogenic nuclide dating reveals how long a surface has been exposed to air by measuring the abundance of rare isotopes produced when cosmic rays interact with minerals.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

Juno has revealed Jupiter’s polar cyclones, complex atmosphere, and diffuse core

The continent-sized cyclones at Jupiter’s poles generate strong winds and ammonia-laden storms. The spacecraft has also collected data on Jupiter’s unique magnetic field, which resembles a blend of Earth’s and Uranus/Neptune's.

Particle detection has evolved from cloud and bubble chambers to digital 3D displays

As invisible particles passed through cloud and bubble chambers, they disrupted supersaturated vapor and superheated liquid, respectively, creating trails that served as proxies for cosmic rays. The transition from photographed events to digital sensors enhanced data collection and accuracy.

Except for Mercury, every planet in the solar system experiences auroras

Lacking magnetic fields, Venus and Mars exhibit auroras when the solar wind collides directly with their atmospheres, without deflection. Some particles behind the atmospheric collisions that generate auroras on gas giants come from their moons and the surrounding environments.

Explore a 3D interactive visualization of Neptune, the smallest of the solar system's giant planets.

Simulations suggest ice's slipperiness comes from rearranging molecules

Past models have proposed that slipperiness arises from a thin layer of liquid water formed at the ice's surface by frictional melting. However, new research suggests that electromagnetic forces between interacting surfaces push water molecules out of an ordered, crystalline structure and into a shapeless, soft, slippery layer. This process occurs solely through contact, independent of pressure or friction.

A startup is trying to create the diamond equivalent of the gold standard

It's called the Diamond Standard Co, and it uses an algorithm to assign standard values to a variety off small diamonds, grouping them together into individual coins. Historically, diamonds haven't been able to be classified as commodities or standardized like gold because they aren't uniform—factors such as clarity, cut, color, and carat size significantly influence the value of a diamond.

Visualize water's abundance across the solar system, and its relative rarity on Earth

Despite covering almost three-quarters of its surface, water only makes up about 0.12% of Earth's volume. Water in some of Jupiter's and Saturn's moons comprises a larger share of those celestial bodies and of the total water in the solar system. For example, Jupiter's moon Ganymede is believed to harbor almost nine times Earth's oceans beneath its icy shell.

Geode formation begins with trapped gas bubbles in igneous or sedimentary rock

Over thousands or millions of years, water seeps into the cavity created by the bubble and deposits minerals, which slowly build and crystallize into quartz, agate, amethyst or other crystals.

Scientists are experimenting with ways to probe the multiverse theory

Researchers are simulating vacuum bubbles—the theorized starting points of universes—using quantum computers, digital models, and exotic lab setups to study how they form, expand, and possibly collide. One experiment aims to "blow" artificial universe-like bubbles inside ultra-cold quantum gases, potentially capturing real-time glimpses of cosmic birth processes in a lab.

Earth's first oceans may have been as much as 230 degrees Celsius (446 degrees Fahrenheit), with atmospheric pressure preventing them from boiling.

Dust particles on Mars can generate lightning

Through triboelectric charging, sand and dust on the Martian surface can become electrified when they rub against one another, causing friction to displace electrons and create charged particles. If this matter forms a strong enough electric field, it can overcome atmospheric insulation and produce electrical discharges, resembling lightning on Earth.