How Big Is Jupiter’s Great Red Spot?
The Great Red Spot has no single fixed size. NASA reported a width of about 10,250 miles — 16,500 km — in 2014. That is a dated observation, not a measurement of the storm today.
See observation dates and sourcesCould Earth fit across the 2014 measurement?
In the width direction, yes: about 16,500 km was roughly 1.3 Earth equatorial diameters. That comparison describes one axis. It does not establish how an Earth-sized circle would fit inside the storm’s complete outline.
For context, NASA’s historical comparison reported widths of about 13,020 miles in 1995 and 11,130 miles in 2009. The shrinking width is visible in the common-scale bars above.
A storm changes shape as well as size
A later Hubble study watched the storm over roughly 90 days, from December 2023 to March 2024. Its size and elliptical shape varied over that observation period. Long-term shrinkage does not mean every short-term measurement must decrease smoothly.
The NASA page carrying the 2014 measurements was maintained in 2025. Its later webpage date does not turn those observations into 2025 measurements.
Why older comparisons disagree
A claim that the storm spans one, two or more Earths may refer to a different year or a different axis. Check the observation date, whether the figure measures width or another dimension, and the source that supplied it.
We do not extend an old annual shrinking rate forward to invent a current diameter or a disappearance date. This guide presents the dated measurements it cites, rather than a live estimate.
For the scale of the whole planet, see our Jupiter and Earth size comparison, which distinguishes diameter, volume and mass.
A little more perspective
What is the Great Red Spot’s current size?
This page does not provide a live measurement. The width diagram covers the cited 1995, 2009 and 2014 observations; the later study describes changes seen from December 2023 to March 2024.
Is the Great Red Spot a circle?
Not a fixed one. Its shape changes, and an elliptical feature can have different long and short axes. The diagram compares reported width only rather than inventing an unmeasured shape.
Why use bars instead of a picture of the storm?
Bars make the measured widths directly comparable. A detailed outline would suggest additional shape and area information that these particular width measurements do not supply.
Sources and measurement notes
- NASA · Hubble’s historical Great Red Spot measurements
May 15, 2014. Reports the 1995, 2009 and 2014 widths used in the diagram. The page’s later maintenance date does not change those observation years.
- NASA · The Great Red Spot behaves like a stress ball
October 9, 2024. Describes approximately 90 days of observations from December 2023 to March 2024; supports changing size and shape, not a live 2026 width.
- NASA · Planetary comparison reference
Earth’s equatorial diameter supplies the common width reference.
Content reviewed . Observation dates and measurement conventions are stated separately above.