Solar System
25 reportsPlanet formation and small bodies support the strongest interpretation available. The account remains focused on which formation questions remain open and what meteorites reveal, showing how sparse measurements or incomplete records limit certainty.
Webb spots puzzling changes in Chariklo's rings between Saturn and Uranus
The James Webb Space Telescope has recorded unexpected changes in the rings of Chariklo, a small centaur object between Saturn and Uranus, challenging assumptions about the stability of minor ring systems in the outer solar system.
Why Venus Is Hotter Than Mercury, Even Though It's Farther from the Sun
Venus's surface is hotter than Mercury's, despite being farther from the Sun. The reason lies in Venus's thick, heat-trapping atmosphere-not its distance from our star.
Mercury's Surface Hides Evidence of Greater Planetary Shrinkage
A new study using NASA MESSENGER data finds Mercury may have shrunk by up to 30 percent more than earlier models indicated, with impact debris masking the true scale of planetary contraction
Venus Reveals Its Crescent Phase as It Approaches Inferior Conjunction
Venus is now visible as a striking crescent through small telescopes as it draws closer to Earth and prepares to pass between our planet and the Sun, offering a rare chance to observe its changing phases and orbital motion
Meteorite dust reveals magnetic forces shaped the infant solar system
Analysis of ancient meteorite grains has uncovered evidence that strong magnetic fields influenced the earliest stages of the solar system's formation, challenging the long-held view that gravity alone sculpted the protoplanetary disk
Comet McNaught Surges in Brightness After Solar Outbursts
Comet 220P/McNaught unexpectedly brightened by a factor of 20,000 during two recent outbursts near its closest approach to the Sun, offering a rare opportunity for telescopic observation before it fades from view
Pioneer 11's Saturn Flyby Tested the Limits of Deep Space Navigation
NASA's Pioneer 11 spacecraft became the first probe to traverse Saturn's rings in 1979, gathering data on the planet's moons, rings, and magnetic field while clearing the way for later missions to the outer solar system
Pluto's Planet Status Revisited as Astronomers Debate IAU Definition
Two decades after Pluto was reclassified as a dwarf planet, new observations and ongoing debate among planetary scientists are challenging the criteria that define what counts as a planet in our solar system
Voyager 2's Launch Opened the Outer Solar System to Exploration
NASA's Voyager 2 spacecraft began its journey to the outer planets on August 20, 1977, using a rare planetary alignment to visit Jupiter, Saturn, Uranus, and Neptune and extend humanity's reach into interstellar space
How to Observe a Shadow Cast by Venus in the Night Sky
Venus is nearing its peak brightness, offering a rare chance to observe whether the planet can cast a visible shadow. Astronomers explain the conditions and techniques needed to detect this subtle phenomenon.
Comet 220P/McNaught Imaged in Unusual Bright Outburst Over Namibia
Astrophotographers in Namibia have captured a rare, vivid image of comet 220P/McNaught during a dramatic brightening event, using a 12-inch telescope and advanced camera equipment
Pluto's Atmosphere Shows Signs of Collapse as It Moves Away from the Sun
Astronomers tracking Pluto's atmosphere with stellar occultation techniques report a measurable drop in atmospheric pressure, suggesting the dwarf planet's nitrogen-rich envelope is beginning to freeze out as Pluto recedes from the Sun
What to Expect During the Five Stages of the 2026 Total Solar Eclipse
On August 12, 2026, a total solar eclipse will cross parts of Europe and the Arctic, offering a rare opportunity to observe the Sun's atmosphere and dynamic eclipse phenomena as the Moon's shadow sweeps across Earth's surface
Crescent Moon and Mars Align Over Taurus Before Dawn on August 9
Observers in the Northern Hemisphere will see the crescent Moon pass close to Mars in the constellation Taurus before sunrise on August 9, offering a preview of the winter starscape and a rare opportunity for binocular viewing.
NASA's Juno Mission Transformed Jupiter Science After 2011 Launch
NASA's Juno spacecraft, launched in 2011 on an Atlas V rocket, reached Jupiter in 2016 and has since delivered unprecedented data and images, reshaping our understanding of the giant planet's atmosphere, magnetic field, and moons
Neptune's Inner Moons May Preserve Debris From Ancient Ice Worlds
Infrared observations from the James Webb Space Telescope reveal unexpected clay minerals on two small Neptunian moons, supporting a debris-origin scenario while leaving the fate of their original ice unresolved
Aug. 12, 2026, brings an unusually complete night of skywatching
On Aug. 12, 2026, observers can follow a solar eclipse by day, then watch Venus, the Perseid meteor shower and the Milky Way under a nearly moonless sky
Mercury and Jupiter Meet as Venus Rules August Skies
Venus reaches its widest evening separation from the Sun on Aug. 15, while Mercury and Jupiter pass within 0.6 degrees before dawn in a difficult but rewarding conjunction
Triple-Lobed Asteroid 44 Nysa Imaged With Orbiting Moon in Asteroid Belt
Astronomers have resolved asteroid 44 Nysa as the first known triple-lobed body in the main belt, using adaptive optics on major ground-based telescopes. The object also hosts a small moon, raising new questions about asteroid formation and evolution.
Galileo's 1610 Observation of Saturn's Rings Changed Planetary Science
In July 1610, Galileo Galilei used a newly invented telescope to observe Saturn, recording features that would later be identified as the planet's rings-a finding that reshaped our understanding of planetary systems
New Horizons Resumes Science at Solar System's Edge After Hibernation
NASA's New Horizons spacecraft has exited a 321-day hibernation and is now transmitting data from the outer solar system, preparing to study the boundary between the Sun's influence and interstellar space with advanced instruments
Juno Mission Probes Subsurface Heat on Jupiter's Volcanic Moon Io
NASA's Juno spacecraft has measured temperatures beneath Io's surface, revealing intense internal heating and unexpectedly smooth, low-density terrain. The findings, published in a peer-reviewed journal, offer new insight into tidal heating on active moons
How Perseid Meteors Trace a Journey from Comet to Night Sky
The Perseid meteor shower offers a glimpse into the solar system's ancient debris, as fragments from comet 109P/Swift-Tuttle enter Earth's atmosphere and produce visible streaks of light each August
James Webb Telescope Detects Unidentified Infrared Signal on Titan and Pluto
The James Webb Space Telescope has recorded a mysterious infrared absorption feature on both Saturn's moon Titan and the dwarf planet Pluto, hinting at shared surface chemistry despite their contrasting environments
How the Heliosphere Shields the Solar System from Interstellar Space
Researchers are mapping the heliosphere, the vast bubble created by the solar wind that surrounds the Sun and planets, to understand how it protects the solar system from cosmic radiation and shapes planetary environments