Asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called asteroids or minor planets. It is also called the main asteroid belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids. About half its mass is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid belt is about 4% that of the Moon. Ceres, the only object in the asteroid belt large enough to be a dwarf planet, is about 950 km in diameter, whereas Vesta, Pallas, and Hygiea have mean diameters less than 600 km. The remaining bodies range down to the size of a dust particle. — Wikipedia
Dawn was a space probe that was launched by NASA in September 2007 with the mission of studying two of the three known protoplanets of the asteroid belt: Vesta and Ceres. Dawn entered orbit around Vesta on July 16, 2011, and completed a 14-month survey mission before leaving for Ceres in late 2012. It entered orbit around Ceres on March 6, 2015. In 2017, NASA announced that the planned nine-year mission would be extended until the probe’s hydrazine fuel supply was depleted. On November 1, 2018, NASA announced that Dawn had depleted its hydrazine, and the mission was ended. The spacecraft is currently in a derelict, but stable, orbit around Ceres. Dawn is the first spacecraft to orbit two extraterrestrial bodies, the first spacecraft to visit Vesta and Ceres, and the first to orbit a dwarf planet. — Wikipedia
In 1596, Johannes Kepler wrote, “Between Mars and Jupiter, I place a planet,” in his Mysterium Cosmographicum, stating his prediction that a planet would be found there. While analyzing Tycho Brahe’s data, Kepler thought that too large a gap existed between the orbits of Mars and Jupiter to fit Kepler’s then-current model of where planetary orbits should be found.
In an anonymous footnote to his 1766 translation of Charles Bonnet’s Contemplation de la Nature, the astronomer Johann Daniel Titius of Wittenberg noted an apparent pattern in the layout of the planets, now known as the Titius-Bode Law. If one began a numerical sequence at 0, then included 3, 6, 12, 24, 48, etc., doubling each time, and added four to each number and divided by 10, this produced a remarkably close approximation to the radii of the orbits of the known planets as measured in astronomical units, provided one allowed for a “missing planet” (equivalent to 24 in the sequence) between the orbits of Mars (12) and Jupiter (48).
When William Herschel discovered Uranus in 1781, the planet’s orbit matched the law almost perfectly, leading astronomers to conclude that a planet had to be between the orbits of Mars and Jupiter.
On January 1, 1801, Giuseppe Piazzi, chairman of astronomy at the University of Palermo, Sicily, found a tiny moving object in an orbit with exactly the radius predicted by this pattern. He dubbed it “Ceres”, after the Roman goddess of the harvest and patron of Sicily. Piazzi initially believed it to be a comet, but its lack of a coma suggested it was a planet. Thus, the aforementioned pattern predicted the semimajor axes of all eight planets of the time (Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, and Uranus). — Wikipedia
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- Modeling reveals how dwarf planet Ceres powers...on August 1, 2022 at 1:37 pm
For a long time, our view of Ceres was fuzzy, said Scott King, a geoscientist in the Virginia Tech College of Science. A dwarf planet and the largest body found in the asteroid belt—the region between Jupiter and Mars speckled with hundreds of thousands of asteroids—Ceres had no distinguishable surface features in existing telescopic observations from Earth.
- NASA releases Webb images of Jupiteron July 15, 2022 at 1:59 pm
On the heels of Tuesday's release of the first images from NASA's James Webb Space Telescope, data from the telescope's commissioning period is now being released on the Space Telescope Science Institute's Mikulski Archive for Space Telescopes. The data includes images of Jupiter and images and spectra of several asteroids, captured to test the telescope's instruments before science operations officially began July 12. The data demonstrates Webb's ability to track solar system targets and […]
- China is considering a nuclear-powered mission to...on July 12, 2022 at 2:23 pm
One look at the Planetary Decadal Survey for 2023–2032, and you will see some bold and cutting-edge mission proposals for the coming decade. Examples include a Uranus orbiter and probe (UOP) that would study Uranus' interior, atmosphere, magnetosphere, satellites, and rings; and an Enceladus orbiter and surface lander to study the active plumes emanating from Enceladus' southern polar region. Not to be outdone, China is also considering a nuclear-powered Neptune Explorer to explore the ice […]
- Equivalent to 1,800 metric tons of TNT: What we...on July 11, 2022 at 3:57 pm
Meteorites hit New Zealand three or four times a year, but the fireball that shot across the sky above Cook Strait last week was unusual.
- When did the sun blow away the solar nebula?on July 11, 2022 at 1:30 pm
The story of our solar system's origin is pretty well known. It goes like this: the sun began as a protostar in its "solar nebula" over 4.5 billion years ago. Over the course of several million years, the planets emerged from this nebula and it dissipated away. Of course, the devil is in the details. For example, exactly how long did the protoplanetary disk that gave birth to the planets last? A recent paper submitted to the Journal of Geophysical Research takes a closer look at the planetary […]
- Study provides new insights about the surface and...on July 7, 2022 at 8:27 pm
When NASA's OSIRIS-REx spacecraft collected samples from asteroid Bennu's surface in 2020, forces measured during the interaction provided scientists with a direct test of the poorly understood near-subsurface physical properties of rubble-pile asteroids. Now, a Southwest Research Institute-led study has characterized the layer just below the asteroid's surface as composed of weakly bound rock fragments containing twice the void space as the overall asteroid.
- NASA asteroid mission on hold due to late...on June 25, 2022 at 10:11 am
NASA put an asteroid mission on hold Friday, blaming the late delivery of its own navigation software.
- Mars as a base for asteroid exploration and miningon June 16, 2022 at 2:14 pm
Mining the asteroids for resources like iron, precious metals, water, or other valuable species may someday become profitable. Mining will probably starting with near Earth objects (NEOs), asteroids whose paths cross the Earth's orbital path. In the long-term, however, mining will want to access the Main Belt of asteroids that orbit between Mars and Jupiter.
- Dead star's cannibalism of its planetary system...on June 16, 2022 at 8:06 am
The violent death throes of a nearby star so thoroughly disrupted its planetary system that the dead star left behind—known as a white dwarf—is sucking in debris from both the system's inner and outer reaches, UCLA astronomers and colleagues report today.
- New maps of asteroid Psyche reveal an ancient...on June 15, 2022 at 4:18 pm
Later this year, NASA is set to launch a probe the size of a tennis court to the asteroid belt, a region between the orbits of Mars and Jupiter where remnants of the early solar system circle the sun. Once inside the asteroid belt, the spacecraft will zero in on Psyche, a large, metal-rich asteroid that is thought to be the ancient core of an early planet. The probe, named after its asteroid target, will then spend close to two years orbiting and analyzing Psyche's surface for clues to how […]
Here are links to pages about closely related subjects.
Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid