Why asteroids are not spherical

Since the International Astronomical Union is less strict on how asteroids are named when compared to other bodies, there are asteroids named after Mr. Spock of "Star Trek" and rock musician Frank Zappa, as well as more solemn tributes, such as the seven asteroids named for the crew of the Space Shuttle Columbia killed in Naming asteroids after pets is no longer allowed. The first spacecraft to take close-up images of asteroids was NASA's Galileo in , which also discovered the first moon to orbit an asteroid in In , after NASA's NEAR spacecraft intensely studied the near-earth asteroid Eros for more than a year from orbit, mission controllers decided to try and land the spacecraft.

Although it wasn't designed for landing, NEAR successfully touched down, setting the record as the first to successfully land on an asteroid. In , Japan's Hayabusa mission became the first spacecraft to land on and take off from an asteroid when it visited the near-Earth asteroid Itokawa. Although the spacecraft encountered a series of technical glitches, it returned a small amount of asteroid material to Earth in June NASA's Dawn mission launched in bound for the main asteroid belt and began exploring Vesta in After a year of work there, it left the asteroid for a trip to Ceres, arriving in Dawn was the first spacecraft to visit either Vesta and Ceres.

The mission ended in when the spacecraft ran out of fuel, although it will continue orbiting Ceres for about 50 years. Japan built on its Hayabusa experience to build a second asteroid sample-return mission, dubbed Hayabusa2.

The spacecraft visited a near-Earth asteroid called Ryugu and studied the body for about 18 months. That work included deploying small hopping rovers and blasting the asteroid with an artificial crater. In December , like its predecessor, Hayabusa2 delivered pieces of Ryugu to Earth for scientists to study with more advanced technology than they can send on spacecraft.

The spacecraft is now trekking back to Earth, with delivery scheduled for September The mission, called Lucy , will fly past one main-belt asteroid and seven Trojans. Scientists hope that by snapping photos of a broad range of Trojans, they can begin to understand why these objects are so diverse, and how their story intersects with that of the solar system at large.

Lucy will make its first flyby in , will make its first Trojan flyby in and is currently scheduled to operate until Also in , NASA will launch its first-ever planetary defense mission to an asteroid.

The DART spacecraft will slam into the small moon of the asteroid Didymos in order to test a technique scientists might be able to use on an asteroid threatening Earth. The impact will occur in late September Scientists believe that Psyche, which is located in the main asteroid belt, contains much higher amounts of metal than most asteroids do. The oddity may mean that Psyche is the bare core of a planet that lost its rocky shell. Scientists also wonder whether metal-rich worlds like these once hosted volcanoes that spilled molten iron across the asteroid's surface.

The Psyche spacecraft will arrive at its target in NASA, other space agencies and private companies are all intrigued by the possibility of extracting resources from asteroids. Water, which can be processed into rocket propellant to save spacecraft from needing to launch the weight of their return fuel, is one commonly proposed resource some are interested in extracting from asteroids, as well as from the moon.

Some people are also interested in mining metals from asteroids, arguing that there are huge amounts of money to be earned from the asteroid belt. Others say that this model is more difficult to make financially viable.

As a result, out there orbiting the Sun we have a giant space rock named for Mr. Spock — a cat named for the character of "Star Trek" fame. There's also a space rock named for the late rock musician Frank Zappa. There are more somber tributes, too, such as the seven asteroids named for the crew of the Space Shuttle Columbia killed in Asteroids are also named for places and a variety of other things. The IAU discourages naming asteroids for pets, so Mr.

Spock stands alone. Asteroids are also given a number, for example Apophis. The Harvard Smithsonian Center for Astrophysics keeps a fairly current list of asteroid names.

Introduction Asteroids, sometimes called minor planets, are rocky remnants left over from the early formation of our solar system about 4. Many Shapes and Sizes Most asteroids are irregularly shaped, though a few are nearly spherical, and they are often pitted or cratered. The S-types "stony" are made up of silicate materials and nickel-iron. Asteroid Classifications Asteroid Classifications Main Asteroid Belt: The majority of known asteroids orbit within the asteroid belt between Mars and Jupiter, generally with not very elongated orbits.

DART team members have filled the spacecraft with fuel, and are running rehearsals as they approach launch on Nov. Planets have plenty of gravity and are largely liquid or even Gas and so form an even sphere around their gravitational centre, with some adjustment for their spin. Asteroids are much smaller and colder and therefore do not respond well to their own weak gravity. Asteroids are conglomerations of smaller units that have drifted together over time.

They have simply retained their lumps and bumps. Pete Nightingale, Reading, UK They are spherical because of their consistence mainly light materials on top, and heavy materials inside and they are moving more slowly than ansteroids do. You can compare this to a raindrop: If it falls down fast, it is not perfectly round but getting an aerodynamic form.

If you compare this to a slowly moving waterdrop in space, it is a nearly perfect sphere. This is because liquids try to get into the sphere form, this is physically the best form to "exist" smallest surface. The thing with the conistence is that planets use both liquid and a more or less hard hull to create their hard cores. If you have ever looked at pictures of our planets , or lined them up side by side to inspect them, then you might notice something interesting—all the planets are round.

When rocks, gas, and dust start to run into each other in space, some pieces may stick together or clump together. As all these bits and pieces of rock, dust, and gas gather, they begin to create their own gravity, which helps hold it all together. These forming planets are very hot, and they are usually molten. Gravity then begins to work on the hot and molten materials. Gravity pulls equally from all sides.