How big is Tarantula Nebula? | Scale of the Universe

The Tarantula Nebula is a giant cloud of glowing gas where new stars are forming. It lies in the Large Magellanic Cloud, a small galaxy that orbits the Milky Way, about 160,000 light-years from Earth. The nebula is about 1,000 light-years across, where a light-year is the distance light travels in one year, about 9.46 trillion kilometers. As of 2026, it is the brightest star-forming region known in the Local Group, the family of galaxies that includes the Milky Way.

Size

A nebula has no sharp edge. The Tarantula's glowing gas, hot stars and warm dust spread over several hundred parsecs, where a parsec is about 3.26 light-years.

A 2019 review of the nebula gives it a radius of about 10 arcminutes on the sky, where an arcminute is a sixtieth of a degree. At the nebula's distance of about 50,000 parsecs, that radius is 150 parsecs. The nebula is therefore about 300 parsecs, or 980 light-years, across.

Other measurements give similar sizes. A survey of giant star-forming regions, summarized in the same review, found a diameter of 370 parsecs, about 1,200 light-years. NASA's Chandra X-ray Center describes the nebula as about 1,100 light-years across.

The brightest part of the nebula, called NGC 2070, is about 40 parsecs (130 light-years) across. At its heart is R136, a tight cluster of young stars only about 2 parsecs (6.5 light-years) across.

Size comparisons

Seen from Earth, the nebula is about 20 arcminutes wide, about two-thirds the width of the full Moon.
If the Sun were shrunk to the size of a basketball, the Tarantula Nebula would be about 1.6 million kilometers (1 million miles) across, about four times the distance from Earth to the Moon.
In a survey that measured giant star-forming regions the same way, the Tarantula is nearly twice as wide as the Great Nebula in Carina and gives off about 19 times as much light from glowing hydrogen.
It gives off about a thousand times as much of the ultraviolet light that makes gas glow as the Orion Nebula does.
It is about three times as wide as Barnard's Loop, a faint arc of glowing gas in the constellation Orion.

The stars that light it

The Tarantula glows because hot, massive young stars flood it with ultraviolet light, which strips electrons from its hydrogen atoms. Most of that light comes from stars in NGC 2070, including the R136 cluster at its center.

R136 is no more than 2 million years old. Studies of its brightest members estimate masses of 150–300 times the mass of the Sun, and a 2019 review called them the most massive stars identified to date. Such estimates are uncertain, and they would be lower if some of these stars turn out to be pairs.

Star formation here began about 25 million years ago and peaked a few million years ago. Hodge 301, an older cluster about 45 parsecs (150 light-years) from R136, is 20–30 million years old. Supernovae, the explosions that mark the death of a massive star, have probably already cleared away most of the gas there. About 90 parsecs (290 light-years) from R136, a group of stars called NGC 2060 holds a pulsar, the fast-spinning core left behind when a massive star explodes, and the remains of a supernova.

Name and discovery

The astronomer Nicolas-Louis de Lacaille first recorded the nebula in 1751. It is bright enough to see with the unaided eye from the Southern Hemisphere, in the constellation Dorado. It is named for its long, dusty filaments, which in telescope images look like the legs of a spider. Astronomers also call it 30 Doradus.