The solar system formed between 4.5 and 4.6 billion years ago

How solar systems form

Learn how our sun, the planets, and other solar system bodies came to be with these videos and an infographic from NASA. Use this resource to visualize how the solar system formed and to model and describe the process.

Comets serve as time capsules of the early solar system

The frozen objects preserve the molecular composition of the solar system's formation, dating back about 4.6 billion years. Spectral analysis of the gases they release when heated upon approaching the sun in eccentric orbits reveals this composition and helps assess solar system formation models.

Asteroids are the rocky remains of the solar system's formation

These celestial bodies were not integrated into the precursors of planets about 4.6 billion years ago and instead continue to orbit the sun, primarily within a band between Mars and Jupiter—the asteroid belt.

The Earth orbits the sun within the Orion Spur arm of the Milky Way galaxy

The solar system is roughly halfway between the galaxy's outer rim and its center, which is located about 25,000 light years away. The Milky Way is itself one of hundreds of thousands of galaxies in the Virgo Supercluster.

Learn how the Earth was made

Four and a half billion years ago the Earth formed from dust in space to become a molten ball of rock orbiting the sun. Travel back in time to investigate how the Earth was made.

Humans have existed for just 0.004% of Earth’s history

Born from the remains of the molecular cloud that birthed the sun, Earth experienced planetary-scale collisions, asteroid impacts, and lava seas. Life became possible after the planet cooled and formed a thin crust, atmosphere, and oceans.

The sun is not as exceptional as once believed, but it remains rarer than most stars

Once believed to be the center of the universe, the sun is a G-class star, the same category to which about 6% of the Milky Way's stars belong. However, the sun is younger than 85%, more massive than 95%, and more metal-rich than about 93% of all stars. Unlike the sun, half of all stars also exist in multi-star systems.

When it formed 4.5 billion years ago, Jupiter was twice its current size

Its original size was deduced from the orbits of its moons, Amalthea and Thebe. The planet's magnetic field was also 50 times stronger than today, or 400 times stronger than Earth's.

An overview of the sun, from its formation to its role in fueling and protecting life on Earth

With a surface gravity almost 28 times Earth's, the sun's mass exerts enough pressure to raise temperatures in its core above 15 million degrees Celsius (27 million degrees Fahrenheit) and enable nuclear fusion. These reactions produce the energy that sustains Earth's photosynthesis-dependent food chains, while the sun's magnetic field protects the solar system from cosmic ionizing radiation.

Evidence for a ninth planet in our solar system

Is there a massive ninth planet on the edge of our solar system? Many of our solar system's most distant objects tend to swing out in one direction, hinting at evidence for a previously unknown ninth planet potentially larger than Earth. This theoretical planet's orbital period is estimated to be roughly 20,000 years, revolving around the sun at a distance of 60 billion miles. Experts break down the evidence in this quick video.

Hubble revealed that planet-forming disks are common around young stars

One of Hubble’s early images captured 30 young star systems in the Orion region, each surrounded by material that looked like it was forming planets. These systems increased the number of data points scientists had to test planetary formation models.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Webb discovers galaxy that formed 280 million years after the Big Bang

The James Webb Space Telescope has discovered a galaxy that formed just 280 million years after the Big Bang. It is another in a series of increasingly ancient galaxies that, according to current formation models, should not have been able to form so quickly after the birth of the universe.

Earth's core is about 2.5 years younger than its surface according to relativity

Due to differences in where objects are located within gravitational fields, time will run at different rates, which has major impacts on technology that relies on synchronization. For example, GPS satellites run about 38 microseconds faster every day than clocks on Earth's surface, resulting in GPS discrepancies of about six miles, were it not for software corrections.

Learn about solar neutrinos—about 70 billion of which pass through your thumbnail every second

About 100 quadrillion sextillion (10³⁸) of these elusive particles are created in the core every second, making up about 1% of the sun's total energy output. Because they seldom interact with normal matter, highly specialized equipment is needed to detect them, allowing scientists to probe what is happening in the solar core.

The lifetime of a star is determined by its initial mass

More massive stars burn through their fuel at ever-increasing rates, causing them to have shorter lifetimes than less massive stars, despite starting with more hydrogen to fuse. In clusters of stars that likely formed together, observing what mass stars are no longer fusing hydrogen estimates the age of the cluster.

The intensity of auroral activity approximately follows the sun's 11-year cycle

The density, speed, and temperature of material ejected by the sun are at their lowest at the start of each cycle, resulting in weaker interactions with Earth's magnetic field and muted, diffuse auroras. While the average solar wind speed is about 300 kilometers (186 miles) per second, the fastest winds can be more than three times faster.

A four-billion-year-old meteorite reignited the debate about life on Mars

Recovered from Antarctica in 1984, ALH84001 contained organic compounds, magnetite and iron sulfide grains of potential biological origin, and features that resembled fossilized bacteria. With technological advancements, scientists found abiotic origins for these features in the following decades.

The International Space Station is powered entirely by large solar arrays

Launched in 1998, its original solar panels were designed to withstand no more than 20 years of wear from temperature swings and micrometeoroid impacts in space. Replacement panels that roll out like carpets have since been installed.

Solar wind may have contributed to Mars losing its atmosphere

Scientists believe that over hundreds of millions of years, energetic particles from the sun colliding with atmospheric particles, flinging them away from Mars' weak gravitational field like colliding billiard balls. As atmospheric pressure decline, water also evaporated away from the surface.

The Planetary Society provides an active role in advancing space exploration

Founded in 1980 by Carl Sagan, Louis Friedman, and Bruce Murray in response to public interest in space not adequately reflected in government investment, it is now the world’s largest nonprofit space organization, with more than 2 million members.

Ancient civilizations predicted eclipses by tracking different cycles of their recurrence

The periodic nature of the orbits of the sun, moon, and Earth results in several series called saros cycles, in which the geometric configuration of these celestial bodies that produces an eclipse recurs after about 6585 days. Because eclipses are viewable from different locations on Earth, there exist many saros cycles, one for each ecliptic configuration.

The Antikythera mechanism is the oldest example of an analog computer

Remains of the 2,000-year-old hand-powered model of the solar system were uncovered in a shipwreck off the coast of Greece in 1900. It had been used to calculate the motions of the sun, moon, and planets to help forecast events such as solar eclipses.

View media of the sun's south pole, taken for the first time in 2025

Captured in March 2025 by the Solar Orbiter—a satellite developed by ESA and NASA—the images and video are the first to be taken by an object not moving around the sun's equator. The orbiter moved outside the plane of the planets by using Venus to slingshot it into a tilted orbit, and the data it collected will help scientists better understand the sun's magnetic activity.

The team responsible for the first interplanetary sundials included Bill Nye

While reviewing designs for instruments to be carried by future Mars rovers, Nye suggested adapting the function of a calibration tool, which would be used by the Spirit and Opportunity rovers to help calibrate the brightness and color of their panoramic cameras on the Martian surface.

How scientists discovered helium from sunlight over a decade before seeing it on Earth

In 1868, using tools that dispersed light into its constituent colors like a prism, astronomers Pierre Jules César Janssen and Joseph Norman Lockyer independently identified a bright yellow line in the solar spectrum that didn't match any known element. Fourteen years later, amid continued skepticism over the existence of a new element, the same spectral signature was observed in lava on Earth.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

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.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

11 people died from firework injuries in the US in 2024.

One disco producer saw 'Star Wars' four times on its opening weekend and was so inspired that he recorded the album 'Star Wars and Other Intergalactic Funk,' which produced a chart-topping single.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.

Use this tool to calculate the dollar value of your parental mental load, from meal planning to coordinating after-school care, then see resources that help generate solutions.

Salvador Dalí believed he was his own dead brother, who had died nine months before he was born