Solar System
Articles in this section
Comet 3I/ATLAS: A Visitor From Another Star System, Seen by Hubble, Mars Orbiters and More
3I/ATLAS is only the third known interstellar object to pass through our solar system. NASA's telescopes and spacecraft, from Hubble to orbiters at Mars, watched it come and go.
Near-Earth Object 1998 SH2, Tracked as an Asteroid Since 1998, Is Reclassified as a Comet
A NASA-led study in Nature Astronomy found that 1998 SH2 shows a faint tail and gas-driven orbital nudges, so the long-tracked asteroid is now treated as a comet.
Jupiter's Great Red Spot: A Centuries-Old Storm That Keeps Shrinking
The Great Red Spot is a giant storm that has been watched for well over a century and may have been seen in the 1600s. It is smaller than ever, and measurements of its size vary by source.
Why Pluto Isn't a Planet, and Why People Still Argue About It
In 2006 the International Astronomical Union adopted a formal definition of a planet. Pluto does not satisfy all of its criteria.