What is the most massive object in our solar system?
The Sun is the most prominent feature in our solar system. It is the largest object and contains approximately 98% of the total solar system mass. One hundred and nine Earths would be required to fit across the Sun's disk, and its interior could hold over 1.3 million Earths.
The Sun is the largest object in our solar system. Its diameter is about 865,000 miles (1.4 million kilometers). Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest bits of debris in orbit around it.
Believed to lurk at the heart of most large galaxies, supermassive black holes are monstrous in size. The Milky Way's supermassive black hole — Sagittarius A* (Sgr A*) — has a sizeable mass of roughly 4.5 million times that of the Sun.
Ton618 has a mass of somewhere around 66,000,000,000 solar masses. The Great Attractor has a mass of somewhere in the neighborhood of 1,000,000,000,000,000 solar masses, or six orders of magnitude more.
The biggest single entity that scientists have identified in the universe is a supercluster of galaxies called the Hercules-Corona Borealis Great Wall. It's so wide that light takes about 10 billion years to move across the entire structure. For perspective, the universe is only 13.8 billion years old.
Titan, the largest moon of Saturn, is named for the Titans of Greek mythology, which include Cronus (equated with the Roman god Saturn) and his 11 siblings. Titan is larger than the planet Mercury and more massive than Pluto, and, in significant ways, it resembles a planet more than it does a typical moon.
Its only noticeable feature is the long streamer of gas emanating from the galactic center. The source of that jet is far from prosaic, however: It's a black hole 6.6 billion times the mass of the Sun. No other known object is as massive—this black hole by itself outweighs entire star clusters and small galaxies.
Earth is closer to that limit than anything else in our Solar System, and the combination of its relatively dense composition and its enormous self-gravity, as we're 18 times as massive as Mercury, places us alone as the densest object in our Solar System.
The planet is mostly swirling gases and liquids. While a spacecraft would have nowhere to land on Jupiter, it wouldn't be able to fly through unscathed either. The extreme pressures and temperatures deep inside the planet crush, melt, and vaporize spacecraft trying to fly into the planet.
Jupiter. Jupiter is the largest planet in the solar system. It's about 11 times wider than Earth with an equatorial diameter of 88,846 miles (about 142,984 kilometers).
Astronomers discover "Farfarout" — the most distant known object in the solar system. The 250-mile-wide (400 km) dwarf planet is located about 140 times farther from the Sun than Earth (3.5 times farther than Pluto), and soon may help serve as evidence for a massive, far-flung world called Planet 9.
Ultra-massive black holes are the most massive objects in the universe. Their mass can reach millions and billions of solar masses. Supercomputer simulations on TACC's Frontera supercomputer have helped astrophysicists reveal the origin of ultra-massive black holes formed about 11 billion years ago.
Titan is extremely cold, with an annual temperature of -180 C (-291 F), but thankfully, due to its thick atmosphere, humans walking outside on titan would only need warm clothing and respirators. Titan's atmosphere lacks oxygen; however it contains ice water below its surface that can be used as a source of oxygen.
It took the Cassini-Huygens spacecraft nearly 7 years to get to Saturn, because it did not travel directly to Saturn. It had to fly by several planets on its way, using their gravity to give it the "energy boost" needed to get all the way to Saturn.
Ganymede is one of the four Galilean moons discovered by Galileo in 1610. It is the largest of Jupiter's seventy-nine moons and the largest moon in the solar system. With a diameter of 5,148 kilometers (3,273 miles), Ganymede is slightly larger than Mercury but almost 2.4 times smaller than Earth.
