Solar System

If Pluto's downgraded status to a dwarf planet has got you down, consider this: Scientists think there's a chance our solar system could catch a new planet. The first ever observed so-called Interstellar Object was reported in 2017, a reddish, cigar-shaped rock astronomers named Oumuamua. Although it left in 2022, scientists believe an object with the right mass and trajectory might take a seat at the planetary table. Learn how it would work here.

NASA's Eyes on the Solar System allows you to track all kinds of objects in space in real time, from observatories like the James Webb Telescope to all manner of comets and asteroids. Zoom in and out, read up on space missions, and see the solar system from a totally new angle with this incredible interactive site. Jump in here.

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.

The fertile, ocean-bearing Earth is surrounded by planets that are dry to the bone. This article details how Earth might've managed to get and stay damp. In the solar system's early days, planets near the coalescing sun were too hot for water. Some worlds farther away, like Jupiter and Saturn, didn't have the same issue, so even some of their moons were covered in water. Scientists aren't exactly sure how the water came to the inner planets, but there are a few theories, such as how asteroids hitting the Earth may have acted like "cosmic water balloons."

The infographic from 2020 illustrates the complexity of our solar system, mapping over 18,000 objects including asteroids, comets, planets, and moons. Created by biologist Eleanor Lutz using data from NASA, it shows the non-linear distribution of objects due to the sun's gravitational pull. Objects nearer to the sun are more numerous, forming tighter orbits, while those farther out are fewer and more widely spaced.

This interactive model of our local neighborhood in the Orion arm of the Milky Way galaxy lets you sail and zoom around our Solar System. Learn about various different objects (include planets and manmade planet-exploring probes) and their proximity to Earth and other heavenly objects.

NASA provides a re-introduction to our solar systems's planets, and a few other neighborhood residents. In the Milky Way galaxy, there are more planets than stars. We’ve discovered thousands of planets orbiting distant stars, but it all started with the current lineup of eight planets orbiting our own star—the sun. Learn more here.

That familiar orb in our night sky must have come from somewhere. The most widely accepted theory about the Moon's origin is the giant-impact theory, suggesting the Moon formed as a result of a massive collision between early Earth and another small planet named Theia. Analysis of samples brought back from the Apollo missions revealed chemical similarities between the Earth and Moon, supporting this theory. The Moon's formation stabilized Earth's orbit and reduced polar motion, contributing to our planet's relatively stable climate. In this piece, planetary scientists weigh in on the best theories explaining the origins of the moon.

From modulating our tides to impact our climate, Earth's lone natural satellite plays a key role forming the planet's habitat. Before diving into the rest of the resources on this page, check out NASA's overview of the basics of the Moon—how it got its name, its size and distance from Earth, its structure, and much more.

Mars formed at the same time as the rest of the solar system, about 4.6 billion years ago. Today, Mars is a cold, dry world with a thin atmosphere. However, there is evidence that Mars was once much more habitable, covered in flowing rivers a large bodies of water. Scientists believe over time the planet lost its magnetic field, leading to the loss of atmosphere and ultimately the evaporation of water.