“101955 Bennu (provisional designation 1999 RQ36) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999. It is a potentially hazardous object that is listed on the Sentry Risk Table with the second-highest cumulative rating on the Palermo Technical Impact Hazard Scale. It has a cumulative 1-in-2,700 chance of impacting Earth between 2175 and 2199. Its name references Bennu, the ancient Egyptian mythological bird associated with the Sun, creation, and rebirth.
101955 Bennu has a mean diameter of approximately 492 m (1,614 ft; 0.306 mi) and has been observed extensively with the Arecibo Observatory planetary radar and the Goldstone Deep Space Network.
Bennu is the target of the OSIRIS-REx mission which is intended to return samples to Earth in 2023 for further study. On 3 December 2018, the OSIRIS-REx spacecraft arrived at Bennu after a two-year journey. Before attempting to obtain a sample from the asteroid, it will map out Bennu’s surface in detail and orbit the asteroid to calculate its mass.”
“NASA’s InSight has been busy. After landing on the Red Planet, the mission sent home pictures and sound, then placed its first instrument on the planet’s surface. Plus, find out what the Curiosity rover has been up to. “
“InSight is a robotic lander designed to study the interior of the planet Mars. The mission launched on 5 May 2018 and is expected to land on the surface of Mars at Elysium Planitia on 26 November 2018, where it will deploy a seismometer and burrow a heat probe. It will also perform a radio science experiment to study the internal structure of Mars.
The mission is managed by the Jet Propulsion Laboratory for NASA. The lander was manufactured by Lockheed Martin Space Systems and was originally planned for launch in March 2016. The name is a backronym for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport.
InSight’s objective is to place a stationary lander equipped with a seismometer called SEIS produced by the French space agency CNES, and measure heat transfer with a heat probe called HP3 produced by the German space agency DLR to study the planet’s early geological evolution. This could bring new understanding of the Solar System’s terrestrial planets — Mercury, Venus, Earth, Mars — and the Earth’s Moon. By reusing technology from the Mars Phoenix lander, which successfully landed on Mars in 2008, it is expected that the cost and risk will be reduced.”
“InSight is a robotic lander designed to study the interior of the planet Mars. The mission launched on 5 May 2018 and is expected to land on the surface of Mars at Elysium Planitia on 26 November 2018, where it will deploy a seismometer and burrow a heat probe. It will also perform a radio science experiment to study the internal structure of Mars.
The mission is managed by the Jet Propulsion Laboratory for NASA. The lander was manufactured by Lockheed Martin Space Systems and was originally planned for launch in March 2016. The name is a backronym for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport.
InSight’s objective is to place a stationary lander equipped with a seismometer called SEIS produced by the French space agency CNES, and measure heat transfer with a heat probe called HP3 produced by the German space agency DLR to study the planet’s early geological evolution. This could bring new understanding of the Solar System’s terrestrial planets — Mercury, Venus, Earth, Mars — and the Earth’s Moon. By reusing technology from the Mars Phoenix lander, which successfully landed on Mars in 2008, it is expected that the cost and risk will be reduced.”
“Less than 2 minutes after the launch of a 58-foot-tall (17.7-meter) Black Brant IX sounding rocket, a payload separated and began its dive back through Earth’s atmosphere. When onboard sensors determined the payload had reached the appropriate height and Mach number (38 kilometers altitude, Mach 1.8), the payload deployed a parachute. Within four-tenths of a second, the 180-pound parachute billowed out from being a solid cylinder to being fully inflated. It was the fastest inflation in history of a parachute this size and created a peak load of almost 70,000 pounds of force.”
“The Dawn mission was designed to study two large bodies in the asteroid belt in order to answer questions about the formation of the Solar System, as well as to test the performance of its ion drive in deep space. Ceres and Vesta were chosen as two contrasting protoplanets, the first one apparently “wet” (i.e. icy and cold) and the other “dry” (i.e. rocky), whose accretion was terminated by the formation of Jupiter. The two bodies provide a bridge in scientific understanding between the formation of rocky planets and the icy bodies of the Solar System, and under what conditions a rocky planet can hold water.
The International Astronomical Union (IAU) adopted a new definition of planet on August 24, 2006, which introduced the term “dwarf planet” for ellipsoidal worlds that were too small to qualify for planetary status by “clearing their orbital neighborhood” of other orbiting matter. Dawn is the first mission to study a dwarf planet, arriving at Ceres a few months before the arrival of the New Horizons probe at Pluto in July 2015.
Ceres comprises a third of the total mass of the asteroid belt. Its spectral characteristics suggest a composition similar to that of a water-rich carbonaceous chondrite. Vesta, a smaller, water-poor achondritic asteroid comprising a tenth of the mass of the asteroid belt, has experienced significant heating and differentiation. It shows signs of a metallic core, a Mars-like density and lunar-like basaltic flows.
Available evidence indicates that both bodies formed very early in the history of the Solar System, thereby retaining a record of events and processes from the time of the formation of the terrestrial planets. Radionuclide dating of pieces of meteorites thought to come from Vesta suggests that Vesta differentiated quickly, in three million years or less. Thermal evolution studies suggest that Ceres must have formed some time later, more than three million years after the formation of CAIs (the oldest known objects of Solar System origin).
Moreover, Vesta appears to be the source of many smaller objects in the Solar System. Most (but not all) V-type near-Earth asteroids, and some outer main-belt asteroids, have spectra similar to Vesta, and are thus known as vestoids. Five percent of the meteoritic samples found on Earth, the howardite–eucrite–diogenite (HED) meteorites, are thought to be the result of a collision or collisions with Vesta.
It is thought that Ceres may have a differentiated interior; its oblateness appears too small for an undifferentiated body, which indicates that it consists of a rocky core overlain with an icy mantle. There is a large collection of potential samples from Vesta accessible to scientists, in the form of over 1,400 HED meteorites, giving insight into Vesta geologic history and structure. Vesta is thought to consist of a metallic iron–nickel core, an overlying rocky olivine mantle and crust.”
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