Psst, hey there. We’re about to let you in on a really big secret. You know space? It’s a humongous place filled with enormous stuff.
In space, nothing is measured in football fields. For example, the distance between objects in the universe is typically measured in light years, or the distance that light travels in one year (which is about 6 trillion miles).
And objects are also measured on a grand scale. For example, Earth is kind of small in the cosmic scheme of things. We’re easily dwarfed by the planet Jupiter. More than 1,000 Earths would fit in the planet, according to NASA. And the sun? More than a million Earths would fit in there, according to Cornell University.
But guess what? Jupiter and the sun aren’t really that big. There are objects in the universe that make these familiar giants seem puny. Here are five of them.
UP FIRST: Big, big star
The sun is the largest object in our solar system (though some argue that the sun’s heliosphere is actually the largest continuous structure in our corner of the galaxy). But even our sun looks little when it’s compared to the biggest stars we know of.
The sun is a G-type star, a yellow dwarf — pretty average-size on the cosmic scale. But some “hypergiant” stars are much, much larger. Perhaps the biggest star known is UY Scuti, which could fit more than 1,700 of our suns, according to Gizmodo. UT Scuti is only about 30 times more massive than the sun, however, which demonstrates that mass and size don’t necessarily correlate in space.
And while UY Scuti is pretty huge, it isn’t the most massive star out there. That honor goes to a star called R136a1, Gizmodo reports. R136a1 is 265 times more massive than the sun, but its radius is only 30 times that of our nearest star.
In addition to being the most massive star we know of, R136a1 also has the highest luminosity of any known star.
UP NEXT: Big black hole
Ok, so stars are pretty huge, but they’re not the only humongous objects in the universe. Progressing up the list of big cosmic objects, other things to consider are black holes and in particular, supermassive black holes that typically reside in the center of a galaxy. (Our Milky Way hosts one that is about 4 million times the mass of the sun.)
The biggest supermassive black hole is roughly 21 billion times the sun’s mass, and lives in the Coma Cluster, which includes more than 1,000 galaxies. (For comparison, the black hole lurking at the center of the Milky Way totals around 4 million solar masses.)
Astronomers discovered another supermassive black hole in April 2016. That giant is located at the center of the galaxy NGC 1600 and contains roughly 17 billion times the mass of the sun. It’s a little strange that this huge black hole resides in NGC 1600, which is something of a cosmic backwater.
The newly spotted black hole lies 200 million light-years from Earth in the constellation Eridanus and belongs to an average-size galaxy group, whereas other monster black holes discovered to date tend to be found in dense clusters of galaxies. So researchers may have to rethink their ideas about where gigantic black holes reside, and how many of them might populate the universe.
UP NEXT: Gigantic galaxy
Monster black holes are, well, monstrous, but they are also not the biggest things in the whole wide universe. What’s bigger than a supermassive black hole? A galaxy, for one thing.
Galaxies are collections of star systems and all that is inside those systems (such as planets, stars, asteroids, comets, dwarf planets, gas, dust and more). Our own Milky Way is about 100,000 light-years across, NASA says; a light-year is the distance light travels in a year. It’s difficult to characterize what the largest galaxies are, because they don’t really have precise boundaries, but the largest galaxies we know of are millions of light-years across.
Take the supergiant elliptical galaxy IC 1101, for example. Located at the center of the Abell 2029 galaxy cluster, IC 1101 is approximately 1.04 billion light-years from Earth, and is often referred to as the largest galaxy in the universe (though, again, there’s no way of definitively proving how large it really is). What we do know for certain is that IC 1101 is much bigger than our Milky Way — about 50 times the size of our galaxy and 2,000 times more massive, to be exact.
UP NEXT: Bigger than the biggest galaxy
Now at last we are starting to approach the biggest structures in the universe. Galaxies are often bound to each other gravitationally in groups that are called galaxy clusters. (The Milky Way, for example, is part of the small Local Group that comprises about two dozen galaxies, including the Andromeda Galaxy.)
Galaxy clusters are collections of galaxies that formed once stars and individual galaxies had been built. Gravity binds hundreds of thousands of galaxies together in collections so large, they can distort the fabric of space-time. According to present understanding, the massive objects should take billions of years to form.
In 2012, scientists used NASA’s Spitzer Space Telescope to measure the galactic cluster IDCS 1426, which lies approximately 10 billion light-years from Earth. Because light takes a full year to travel the distance of 1 light-year, that means astronomers are able to study the cluster as it appeared when the universe was only 3.8 billon years old.
Initial estimates suggested that IDCS 1426 contained an enormous mass at a significant distance, but were not conclusive. Brodwin and his colleagues decided to use NASA’s Hubble Space Telescope, Keck Observatory and Chandra X-ray Observatory to refine measurements of the mass of the cluster, using three different methods.
All three observations independently provided a mass 250 trillion times higher than the mass of the sun, or 1,000 times more massive than the Milky Way. But IDCS 1426 is not the most massive galaxy cluster in the universe. That distinction is held by a massive cluster that lies only 7 billion light-years from Earth.
Known informally as ‘El Gordo,’ the hefty cluster weighs in at a whopping 3 quadrillion times the mass of the sun (that’s 3 followed by 15 zeros, or one thousand million million). However, according to Brodwin, the cluster is on track to grow into something that large.
UP NEXT: Super sized
For a while, astronomers thought that galaxy clusters were the biggest structures in the universe. In the 1980s, however, astronomers realized that groups of galaxy clusters are also connected by gravity and connected in a supercluster.
The biggest supercluster known in the universe is the Hercules-Corona Borealis Great Wall. It was first reported in 2013 and has been studied several times by teams led by the same person. It’s so big that light takes about 10 billion years to move across the structure. For perspective, the universe is only 13.7 billion years old.
The structure first came to light as the research team (led by Istvan Horvath, with the National University of Public Service in Hungary) was looking at brief cosmic phenomena known as gamma-ray bursts. It is thought that they come from supernovas, or massive stars that explode at the end of their lifetimes.
Gamma-ray bursts are thought to be a good indication of where huge masses of stuff lie in the universe, because big stars tend to congregate in dense areas. The first survey showed gamma rays particularly concentrated about 10 billion light-years away in the direction of the Hercules and Corona Borealis constellations.
UP NEXT: Super, super sized
So galaxy clusters may be the largest things in the universe, but it’s still a puzzle as to just how giant structures like the Hercules-Corona Borealis Great Wall came to be. A 2013 article from Discovery News (a partner site to Space.com) pointed out that this structure appeared to go against a principle of cosmology, or how the universe formed and evolved. Specifically, this principle says that matter should be uniform when seen at a large enough scale. The largest known supercluster, however, is not uniform.
“I would have thought this structure was too big to exist. Even as a coauthor, I still have my doubts,” Jon Hakkila, an astronomy researcher at the College of Charleston in South Carolina, said in a 2014 press release. He said there is a very small chance the researchers saw a random number of gamma-rays in that location, but it is far less than one in 100.
“Thus we believe that the structure exists,” he added. “There are other structures that appear to violate universal homogeneity: the Sloan Great Wall and the Huge Large Quasar Group … are two. Thus, there may very well be others, and some could indeed be bigger. Only time will tell.”