Skip to content

Traverse the graph
Tools
- CompareSide-by-side entities
- SearchThe whole knowledge graph
Hubs
More hubs
Guided
- Learning PathsStructured journeys
- TimelinesSourced chronologies
Featured paths
Open data
API
Reference
Platform
Contribute
About

Loading…

Loading content

A knowledge platform for everything above Earth — astronomy, space, the night sky, celestial events, mythology, and astrology as a clearly separate cultural tradition.

Astronomy is presented as scientific, evidence-based, and sourced. Astrology is presented as cultural, symbolic, and interpretive — never as proven science.

Astronomy

Stars
Constellations
Galaxies
Nebulae

Sky Guide

Night Sky Tonight
Moon Phase
Meteor Showers
Solar Eclipses

Astrology

Zodiac Signs
Birth Chart
Natal Chart
Rising Sign

Calculators

Natal Chart Calculator
Zodiac Sign Calculator
Rising Sign Calculator
Moon Sign Calculator

Encyclopedia

Glossary
History of Astronomy
History of Astrology
Ancient Civilizations

Observatory

Image Library
NASA Gallery
ESA Gallery
James Webb

Guides

Beginner Astronomy
How Stars Form
How Black Holes Work
How Telescopes Work

© 2026 Asteria Star. Everything above Earth — science and tradition, kept clearly apart.

About Editorial Policy Sources Policy llms.txt

Home
Timelines
Planet & Dwarf-Planet Discoveries

Timeline · 4 events

Planet & Dwarf-Planet Discoveries

When the outer worlds of the Solar System were found.

1781
Uranus discovered
Found by William Herschel — the first planet discovered with a telescope.
1846
Neptune discovered
The first planet found through mathematical prediction.
1930
Pluto discovered
Found by Clyde Tombaugh; long counted as the ninth planet.
2006
Pluto reclassified as a dwarf planet
Following the IAU's formal definition of 'planet'.

Sources & references

Facts on this topic will be cited from these primary and reference sources.

NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.
IAUInternational Astronomical Union
Official naming, definitions, constellation boundaries, and astronomical nomenclature.